WO2012070569A1 - Endometrial receptivity measurement method and measurement device, and method for operation of the measurement device - Google Patents

Abstract

Provided are: a method for measuring the mother body's receptivity of implanting an embryo in the uterus (i.e., endometrial receptivity); and a measurement device for use in the method (i.e., an endometrial receptivity measurement device). This method is characterized by employing at least one item selected from the group consisting of an endometrial potential difference, an endometrial impedance and a vaginal mucosal impedance in a living body, which are obtained in a subject, as a measure.

Description

Method of measuring uterine implantation ability, measuring device and method of operating measuring device

The present invention uses a method for measuring the maternal receptive ability (uterine implantation ability) by which a fertilized egg is implanted in the uterus (also referred to as “uterine implantation ability measurement method” in the present invention), and this method is used. The present invention relates to a measuring device (in the present invention, this is also referred to as “uterine implantation ability measuring device”) and a method of operating the measuring device. According to the measurement method, the measurement device, and the operation method of the measurement device of the present invention, it is possible to measure whether or not the maternal uterus is in a state suitable for implantation of a fertilized egg. It is possible to provide visual diagnosis of uterine implantation ability and treatment resulting therefrom, and as a result, the probability of establishment of pregnancy per treatment cycle can be increased.

In the case of humans, infertility is defined as having no sexual intercourse without contraception for one year. Currently, it is said that 10-15% of all reproductive age couples suffer from infertility. In recent years, with the advancement of women into society, it is considered that there is an increasing trend in the future due to late marriage, late birth and the spread of sexually transmitted diseases.

女性 There are some causes of infertility on the female side, one with ovary (ovulation), one with oviduct (ovum transport), and one with unknown cause. Of these, many infertility with unknown causes are thought to be due to implantation failure. “Implantation” refers to the process by which a fertilized egg (embryo) adheres to and infiltrates the endometrium and is medically defined as having become pregnant at this point. In this implantation process, there is a problem with the endometrium on the receiving side, and as a result, no implantation is called “implantation failure”. That is, “implantation failure” refers to a state in which an embryo that has been successfully developed upon fertilization moves to the uterine lumen but does not normally implant.

Based on the concept that human implantation is controlled by three factors: hormonal environment and endometrial function and morphology, (1) search for blood progesterone levels, and (2) ultrasound diagnostic equipment. There is a history of measuring the thickness of the endometrium used, and (3) collecting the endometrial tissue and conducting a histological examination. The method (3) is highly invasive and is not a forward-looking search even though the endometrial implantation ability changes with each menstrual cycle. I have not been told. On the other hand, (1) and (2) are still performed on a daily basis in clinical practice. However, there are reports that the methods (1) and (2) are insufficient to evaluate the implantation ability of the uterus in a prospective manner, and there are no problems with these parameters on a daily basis. Too many cases do not lead to pregnancy.

In vitro fertilization (in vitro fertilized embryo transfer) has long been one of the common options for infertility treatment, but the pregnancy rate is still less than 30% worldwide. The process until pregnancy is roughly divided into (i) ovulation, (ii) fertilization, and (iii) implantation. However, in the current infertility treatment, if there are any problems regarding (i) and (ii), there are diagnostic methods and treatment methods, but (iii) no diagnostic method is currently used for implantation. Moreover, in in vitro fertilization-embryo transfer, 83% -89% of embryos can develop in vitro, but do not become pregnant. One third of the cause is thought to be caused by the embryo itself, while the remaining two thirds are thought to be caused by a problem in the receiving uterus, so-called implantation failure. For this reason, in current infertility treatment, it is required to diagnose and treat implantation failure. The low success rate of in vitro fertilization often results in excessive economic and mental and physical burdens for couples suffering from infertility. Considering the perinatal prognosis, it is necessary for a couple who wants to raise their children to get pregnant as soon as possible, and for that reason it is necessary to provide efficient infertility treatment. If we can evaluate the implantation ability of the uterus for each menstrual cycle in a forward-looking manner, we can provide treatment that suits the menstrual cycle and can provide efficient treatment. Can alleviate the economic and economic burden.

As described above, in the current infertility treatment, although there is a demand for diagnosis and treatment of implantation failure, there is actually no method for evaluating the implantation ability of the uterus in a forward view. There is currently no diagnostic method for failure.

Conventionally, since the vaginal mucosal impedance of rats shows a high value in the first estrus when non-pregnant, the vaginal mucosal impedance has been put to practical use as a parameter indicating the breeding time (Non-patent Document 1). It has also been reported that this shows a high value in the mouse estrus. However, there is no attempt to evaluate uterine implantation using this parameter.

Aplin JD et al., Ann N Y Acad Sci. 2008 Apr; 1127: 116-20. FEBS Lett. 2006, Vol.580, pp.2717-2722 Masao Koto, et al., “Determining the right time for mating of F344 rats using the vaginal impedance method”, Experimental Animal Technology, 22 (2), 82-85, 1987

An object of the present invention is to provide a method for measuring the uterine implantation ability of a mother. Furthermore, an object of the present invention is to provide a uterine implantation ability measuring apparatus useful for simply measuring the uterine implantation ability of a mother and an operating method of the measurement apparatus.

In order to solve the above-mentioned problems, the present inventors were diligently examining parameters serving as indicators of uterine implantation ability using human implantation failure model mice produced by Nakamura et al., The present inventors. By using the potential difference of the endometrium, endometrial impedance and vaginal mucosa impedance, it is measured forward-looking whether the uterine implantation ability is good, in other words, whether the uterus is ready for implantation. I found that I can do it. Also, as a measuring device, an electrode that can contact the vaginal mucosa epithelium, or that can be inserted into the uterine vagina and can contact the endometrium, can measure the potential emitted from the endometrium or the vaginal mucosa epithelium. When used, the potential difference and impedance can be measured in real time, and as a result, it is considered that efficient embryo transfer can be performed. We were convinced that this would significantly improve the efficiency of current infertility treatment.

The present invention has been completed based on the above findings and includes the following aspects.

(1) Method of measuring uterine implantation ability (1-1) Using at least one selected from the group consisting of endometrial potential difference, endometrial impedance, and vaginal mucosal impedance obtained from the subject as an index Of measuring the endometrial implantation ability of the rat.
(1-2) The method described in (1-1) having the following steps:
(A) At least one value (test value) selected from the group consisting of an endometrial potential difference obtained from a subject, endometrial impedance, and vaginal mucosa impedance is set as the above test value for a fertile woman. A step of comparing with at least one value (control value) selected from the group consisting of a corresponding endometrial potential difference, endometrial impedance, and vaginal mucosal impedance; and (b) the test value is greater than the corresponding control value. And determining that the subject's implantation ability in the menstrual cycle is poor, and determining that the subject's implantation ability in the menstrual cycle is good when the test value is the same or lower than the corresponding control value.
(1-3) The method described in (1-1) having the following steps:
(A ′) comparing at least one value (test value) selected from the group consisting of an endometrial potential difference obtained from a subject, endometrial impedance, and vaginal mucosal impedance with a corresponding threshold value; And (b ′) if the test value is higher than the corresponding threshold value, the subject's implantation ability is determined to be poor, and if the test value is equal to or lower than the threshold value, The process of determining the floor ability as good.
(1-4) The method described in (1-2) or (1-3), which further comprises the following steps:
(C) A step of determining that embryo transfer is to be performed on a subject in the menstrual cycle evaluated as having good implantation ability.

(2) Measuring device for uterine implantation ability (2-1) An apparatus for measuring the implantation ability of the subject's endometrium, which can contact the endometrium or vaginal mucosa epithelium of the subject; Measuring means for measuring an endometrial potential difference generated at the interface between the electrode and endometrium, or an endometrial impedance or vaginal mucosa impedance generated between the electrode and the endometrium or vaginal mucosa epithelium And measuring means for measuring the endometrial implantation ability of the subject using as an index at least one selected from the group consisting of a potential difference of the endometrium obtained from the subject, endometrial impedance, and vaginal mucosal impedance A device comprising:
(2-2) at least one value (test value) selected from the group consisting of an endometrial potential difference obtained from the subject, endometrial impedance, and vaginal mucosal impedance, a predetermined threshold value corresponding thereto, Alternatively, at least one value selected from the group consisting of an endometrial potential difference, endometrial impedance, and vaginal mucosal impedance corresponding to the test value for a fertile woman measured in advance (control value) Comparison means to compare with).
(B) If the test value is higher than the corresponding threshold value or control value as a result of the comparison by the comparison means, the subject's implantation ability in the menstrual cycle is determined to be poor, and the test value corresponds to the corresponding threshold value or A determination means for determining that the implantation ability of the subject in the menstrual cycle is good when the value is equal to or lower than the control value.
(2-3) The apparatus described in (2-1) or (2-2), further comprising the following means:
(C) Output means for outputting the implantation ability of the subject's endometrium obtained by the measurement means.

(3) Method of operating the device for measuring uterine implantation ability (3-1) An apparatus for measuring the implantation ability of a subject's endometrium, which is equipped with an electrode disposed on the endometrium or vaginal mucosal epithelium of the subject. A method for measuring an endometrial potential difference, endometrial impedance, or vaginal mucosal impedance based on a potential generated in the endometrium or vaginal mucosa epithelium of a subject measured by contact with the electrode. Measuring the implantation ability of the subject's endometrium using at least one selected from the group consisting of the measured potential difference of the endometrium of the subject, the endometrial impedance, and the vaginal mucosa impedance as an index. A method of operating the device.
(3-2) The method according to (3-1), further comprising the following steps:
(A) at least one value (test value) selected from the group consisting of the measured potential difference of the endometrium of the subject, endometrial impedance, and vaginal mucosa impedance, and a predetermined threshold corresponding thereto, or , At least one value selected from the group consisting of endometrial potential difference, endometrial impedance, and vaginal mucosal impedance corresponding to the test value for a fertile woman measured in advance (control value) And a step of comparing
(B) If the test value is higher than the corresponding threshold value or control value according to the comparison result, the subject's implantation ability in the menstrual cycle is determined to be poor, and the test value is the corresponding threshold value or control value. The step of determining that the subject's implantation ability in the menstrual cycle is good when the same or lower.
(3-3) The method described in (3-2), which further comprises the following steps:
(C) A step of outputting the measured endometrial implantation ability of the subject.

It is said that 10-15% of all reproductive age couples suffer from infertility. In recent years, with the advancement of women into society, it is considered that there is an increasing trend in the future due to late marriage, late birth and the spread of sexually transmitted diseases. The total number of patients undergoing in vitro fertilization and embryo transfer in Japan is on the rise, and in 2006 the total number of patients exceeded 90,000 per year, and the demand for this treatment from society is increasing. In vitro fertilized embryo transfer has long been one of the common options for infertility treatment, but the pregnancy rate is still less than 30%. If the implantation ability of the uterus can be evaluated in a forward view, an efficient infertility treatment can be provided. As a result, I think that it is possible to get a baby faster than the current situation. The cost of infertility treatment required for pregnancy is reduced, so that couples who have not been able to receive infertility treatment for economic reasons can now receive treatment. As a result, the fertility rate will be improved, and it is expected that this will lead to guaranteeing Japan's economic and social infrastructure that is currently shaken by the declining birthrate problem.

Also, if infertility treatment can be succeeded with a high probability, the cost of medical care is high and the number of times of ovarian stimulation and egg collection with a heavy burden on the mother can be reduced. Furthermore, if the pregnancy rate per embryo transfer improves, the number of transplanted embryos can be limited to one, and iatrogenic multiple pregnancies derived from infertility treatment, which are considered problematic in current perinatal medicine, can be eliminated It is expected.

The result of measuring the pH change of the endometrium of female mice over time after mating ICR mice is shown (Experimental Example 1). The result of having measured the change in the potential difference of the endometrium of female mice over time after mating ICR mice is shown (Experimental Example 2). The result of contrasting the potential difference between the endometrium of the human implantation failure model mouse and the potential difference of the endometrium of the control mouse on the 2.5th day after the mating (immediately before the implantation period) is shown (Experimental Example 3). (A) shows the results of daily measurement of changes in vaginal impedance in vivo in the early pregnancy of untreated ICR mice. (B) shows the results of a comparative study of vaginal impedance in human implantation failure model mice and control mice on day 2.5 after mating (immediately before implantation). It is a block diagram which shows schematic structure of the uterine implantation ability measuring apparatus of one Embodiment of this invention. It is a block diagram which shows schematic structure of the uterine implantation ability measuring apparatus of other embodiment of this invention.

(1) Method for Measuring Uterine Implantability The method for measuring uterine implantation ability according to the present invention is characterized by using the potential difference of the endometrium obtained from the subject or the impedance of the endometrium or vaginal mucosa as an index. .

The potential difference of the endometrium is measured with a known potentiometer, for example, by contacting an electrode made of a glass electrode or a glass-coated antimony electrode with the endometrium, and the contact potential generated between the electrode and the endometrium Can be measured. The electrode is a probe-type electrode so that it can be inserted into the uterine cavity.

The impedance (AC electrical resistance value) of the vagina and endometrium is such that at least two electrodes, such as platinum electrodes or tungsten electrodes, are brought into contact with the vaginal mucosa epithelium or endometrium, and a predetermined frequency is set between the electrodes. An alternating current is applied by applying an alternating voltage. And by this, the current value of the current flowing between each electrode and the vaginal mucosa epithelium or endometrium and the potential generated in the vaginal mucosa epithelium or endometrium (potential difference (voltage value) between the electrodes) are measured. Thus, the impedance of the vagina and endometrium can be detected based on the current value and the voltage value. As in the case of measuring the potential difference as described above, the electrode preferably has a shape (probe type) that can be inserted into the vagina or uterine cavity. In measuring this impedance, either the two-terminal method in which two electrodes are arranged on the vaginal mucosa epithelium or the endometrium or the four-terminal method in which four electrodes are arranged may be used. In some cases, the “Vaginal Impedance Checker” (IMPEDANCE CHECKER FOR RATS MK-11) has already been marketed for the purpose of determining the optimal mating time. The impedance (AC electrical resistance value) of the film may be measured.

Specifically, the measurement method of the present invention is a method for measuring the potential difference of the subject's endometrium, the endometrial impedance, or the vaginal mucosa impedance (collectively referred to as “test value”). ) Values of endometrial potential, endometrial impedance, or vaginal mucosal impedance obtained from a fertile woman (hereinafter referred to as “control”) (collectively these values are referred to as “control values”). "). Here, "fertile woman" literally refers to a woman who can get pregnant. Preferably refers to women who have a history of becoming pregnant.

The measurement can be performed by selecting at least one of the above-described endometrial potential difference, endometrial impedance, and vaginal mucosal impedance values. Although it does not restrict | limit in particular, Two or more can be selected arbitrarily and can also be measured. Although it is one from the viewpoint of simplicity, it is preferable to measure two or more, preferably all three, in order to obtain high accuracy.

Suppose that during the menstrual cycle, sexual intercourse is performed according to ovulation, the rate of live birth per menstrual cycle is considered to be between about 10-25%. In other words, even a fertile woman (a woman who has a history of becoming pregnant) cannot be pregnant every cycle. Implantation failure means that in vitro fertility embryo transfer has become one of the most common treatment methods for infertility, so there are problems in the process of (i) ovulation and (ii) fertilization pregnancy. It is only a concept of the pathology that indicates the situation in which the situation does not lead to pregnancy despite the fact that there is no problem in (i) and (ii) in the situation that can be clearly made. This is because there is currently no diagnostic method for implantation failure. At present, there is no standard for determining that the uterine implantation ability is normal. So far, it has been predicted as a result by (1) blood progesterone level, (2) measurement of endometrial thickness under ultrasound, and (3) date endometrial examination and the presence or absence of consequent pregnancy. . Rather than irreversibly presenting implantation failure in infertility patients, the situation will change with that cycle. In other words, many patients who appear to have infertility due to implantation failure can be treated. Or I think that it is possible to show the state of the endometrium suitable for implantation. This is because it is not uncommon for patients to become naturally pregnant during the treatment suspension. For this reason, it is necessary to evaluate the implantation ability of the uterus forwardly for each menstrual cycle, and to perform treatment appropriate to it.

Note that the subject targeted by the measurement method of the present invention is a woman who wishes to raise a child. In particular, women who are treated for in vitro fertilization and embryo transfer are considered effective as subjects.

As a result of the above comparison, if the test value is higher than the corresponding control value, the implantation ability of the subject in the uterus during the menstrual cycle is not sufficient for embryo implantation, that is, “poor implantation ability” On the other hand, if the test value is the same or lower than the corresponding control value, the implantation ability of the subject in the uterus during the menstrual cycle is sufficient for embryo implantation. That is, it can be judged and determined as “good landing ability”.

For example, if a woman who is going to undergo in vitro fertilization embryo transfer receives the judgment / decision of the former, stop the embryo transfer, cryopreserve the embryo, and until the menstrual cycle becomes “good implantation ability” By postponing embryo transfer, useless embryo transfer can be avoided. On the other hand, if the latter judgment / decision is received, it is judged that the implantation ability of the uterus in the menstrual cycle is appropriate. Therefore, an embryo that has been transplanted or cryopreserved using a fresh embryo is thawed. Perform transplantation. Thus, according to the method of the present invention, an efficient infertility treatment can be provided, and the patient's economic and mental and physical burden can be reduced.

In addition, the measurement method of the present invention can also compare each test value (the potential difference of the subject's endometrium, the endometrial impedance, or the vaginal mucosa impedance) with each preset threshold value. Can be implemented.

As a result of the comparison, if the test value is higher than the corresponding threshold value, the implantation ability of the subject in the uterus during the menstrual cycle is not sufficient for the implantation of the embryo, that is, “poor implantation ability” On the other hand, if the test value is equal to or lower than the corresponding threshold value, the subject's implantation ability in the uterus during the menstrual cycle is sufficient for embryo implantation, that is, Can be judged / decided as “good landing ability”.

(2) Uterine Implantability Measuring Device and Method of Operating the Measuring Device FIG. 5 is a block diagram showing the configuration of a measuring device (uterine implantation ability measuring device) 1 according to an embodiment of the present invention. The uterine implantation ability measuring apparatus 1 includes a measuring electrode 2 inserted into a uterine vagina of a subject, an impedance measuring instrument 10, a control device 6, and an output device 7.

The measurement electrode 2 is formed in a needle shape (probe type) as a whole so that it can be inserted into the uterine vagina of the subject. In the present embodiment, the distal end portion of the needle-like (probe type) body portion 20 is formed. In addition, two electrodes 21 made of a platinum electrode, a tungsten electrode or the like are arranged at a predetermined interval. The distal end portion of the body portion 20 is rounded to prevent rounding of the subject's uterine vagina. When each electrode 21 is brought into contact with the endometrium, a current path is formed between each electrode 21 and the endometrium. When a voltage is applied between the electrodes 21, a current corresponding to an impedance (endometrial impedance) generated between each electrode 21 and the endometrium flows through the current path.

The impedance measuring instrument 10 includes a power source 3, an ammeter 4 that measures a current flowing through the current path, a voltmeter 9 that measures a potential difference (voltage value) between the electrodes 21, and an impedance measuring unit 5. Yes. The power source 3, ammeter 4 and voltmeter 5 and each electrode 21 of the measurement electrode 2 are electrically connected via lead wires.

The power source 3 is a power source for applying an alternating voltage of a predetermined frequency between the electrodes 21, and ON / OFF control of voltage application to the electrodes 21 is performed by the switching element 8. The switching element 8 is controlled to be turned on and off by the impedance measuring means 5.

Impedance measuring means 5 performs energization control to each electrode 21 and control of ammeter 4 and voltmeter 9. The impedance measuring means 5 receives an operation signal from the subject side, performs ON-OFF control of the switching element 8 to control energization of each electrode 21, and uses the voltage value measured by the voltmeter 5 and the ammeter 4. The endometrial impedance is obtained from the measured current value. The impedance measurement method described above is based on a conventionally known method. Moreover, as the impedance measuring instrument 10 for measuring impedance by the two-terminal method as described above, it is preferable to use a “vagina impedance checker” (IMPEDANCE CHECKER FOR RATS MK-11) manufactured by Muromachi Kikai Co., Ltd. it can.

The control device 6 uses the endometrial impedance measured by the impedance measuring instrument 10 to perform measurement processing of the subject's uterine implantation ability. The control device 6 includes a microcomputer, and includes a storage unit such as a ROM 61 and a RAM 62 in addition to the CPU 60 that is a main body of control and calculation. The ROM 61 stores measurement values (control values) of endometrial impedance of fertile women. The RAM 62 temporarily stores the endometrial impedance of the subject measured by the impedance measuring device 10.

The CPU 60 reads the test value of the subject stored in the RAM 62 and compares it with the control value of the fertile woman stored in the ROM 61. If the test value is higher than the corresponding control value, the subject's implantation ability in the menstrual cycle is determined to be poor. On the other hand, when the test value is the same or lower than the corresponding control value, a process for determining that the subject's implantation ability in the menstrual cycle is good is performed.

The output device 7 is composed of a display device such as a liquid crystal display, for example, and the measured value (test value) of the endometrial impedance measured by the impedance measuring instrument 10 or the uterine implantation ability of the subject determined by the control device 6. Display measurement results. Note that the output device 7 is not necessarily limited to the display device, and the measured value (test value) of the endometrial impedance measured by the impedance measuring instrument 10 or the uterine implantation of the subject determined by the control device 6. Various modes can be used as long as the measurement results of performance can be output to the outside.

According to the uterine implantation ability measuring apparatus 1 according to the present embodiment described above, the potential generated in the endometrium of the subject is detected by bringing the electrode 21 into contact with the endometrium of the subject, and this is detected. By measuring the endometrial impedance of the subject based on the potential, the implantation ability of the uterus can be evaluated in real time. This evaluation makes it possible to evaluate the implantation ability of the uterus in front of each menstrual cycle and to treat it.

As mentioned above, although one embodiment of the uterine implantation ability measuring device and the operation method of the measurement device of the present invention was described, the uterine implantation ability measurement device of the present invention and the operation method of the measurement device are limited to this. is not. For example, in the above-described embodiment, the test value (measured value of endometrial impedance) is compared with the measured value (control value) of fertile female endometrial impedance (control value). Although uterine implantation ability is measured, it can also be carried out by comparing the test value with a preset threshold value. Moreover, in the said embodiment, although the measured value of endometrial impedance is used as a test value, by contacting each electrode 21 of the measurement electrode 2 with the subject's vaginal mucosa epithelium, the impedance value of the vaginal mucosa ( By measuring the vaginal mucosal impedance and comparing this vaginal mucosal impedance measurement to a fertile female vaginal mucosal impedance measurement (control value) or a predetermined threshold, subjects in a menstrual cycle It is possible to measure the uterine implantation ability.

In the above embodiment, when measuring the impedance, the impedance is measured by the two-terminal method using two electrodes 21 arranged as the measurement electrode 2, but the impedance is measured by the four-terminal method. It doesn't matter. FIG. 6 shows an impedance measuring instrument 10 ′ according to another embodiment. Similarly to the measurement electrode 2 shown in FIG. 5, the measurement electrode 2 ′ shown in FIG. 6 is formed in a needle shape (probe type) as a whole so that it can be inserted into the uterine vagina of the subject. Four electrodes 21A to 21D made of a platinum electrode, a tungsten electrode, or the like are arranged at a predetermined interval at the distal end of a body (probe type) body 20. The distal end portion of the body portion 20 is rounded to prevent rounding of the subject's uterine vagina.

The electrodes 21A to 21D are electrically connected to the impedance measuring instrument 10 'by lead wires. In this embodiment, it is divided into two electrodes for passing current and two electrodes for measuring voltage, whereas the electrodes 21A, 21D at both ends are electrically connected to the ammeter 4, whereas The remaining electrodes 21B and 21C are electrically connected to the voltmeter 9. The impedance measuring means 5 performs energization control to the electrodes 21A to 21D and control of the ammeter 4 and voltmeter 9. The impedance measuring means 5 receives the operation signal from the subject side, performs ON / OFF control of the switching element 8 to control energization of the electrodes 21A, 21D, and each of the electrodes 21A, 21D as in the above embodiment. Current flows in a current path formed between the uterine and the endometrium. Then, from the current value measured by the ammeter 4 and the voltage value measured by the voltmeter 5, the endometrial impedance can be obtained based on a conventionally known method. As the impedance measuring instrument 10 that measures impedance by the above four-terminal method, “body composition analyzer MLT-50” manufactured by Sekisui Medical Electronics Co., Ltd. can be preferably used.

Furthermore, the uterine implantation ability of the subject can also be measured by using the endometrial potential difference as the test value. In this embodiment, for example, an electrode made of, for example, a glass electrode or a glass-coated antimony electrode as an electrode is brought into contact with the endometrium of the subject, and a contact potential generated between the electrode and the endometrium Is measured by a known potentiometer to measure the potential difference of the subject's endometrium. The potential difference of the endometrium is compared with a measured value (control value) of the potential difference of the endometrium of a fertile woman or a predetermined threshold value, thereby determining the uterine implantation ability of the subject in a certain menstrual cycle. It becomes possible to measure.

Hereinafter, the configuration and effects of the present invention will be described in detail using experimental examples. However, the present invention is not limited to such experimental examples. In the following experimental examples, all animal experiments were conducted with the approval of the Ethics Committee on Animal Experiments at Osaka University Graduate School of Medicine.

Experimental Example 1 Measurement of endometrial pH The expression of various mucins and sugar chains in the uterine cavity controls the adhesion between the fertilized egg (embryo) and the endometrium in the first stage of implantation. (Non-patent document 1: Aplin JD et al., Ann NY Acad Sci. 2008 Apr; 1127: 116-20.). There are mucins and sugar chains at various stages in the endometrium during the implantation phase, and it is generally known that the pH changes when the substance is sulfated or sialylated. Therefore, it is considered that the surface charge changes to negative when mucin and sugar chains are sulfated or sialylated in the endometrium. From this, there is a possibility that the state before and after the implantation of the endometrium can be grasped as a change in pH.

Therefore, the pH of the in vivo endometrium in the early pregnancy was measured every day using ICR mice (CLEA Japan). The pH of the endometrium in vivo was determined by opening the mouse under anesthesia, inserting a probe into the uterine cavity from the vagina, and using a laboratory precision digital pH / mV meter (MODEL: CL-9D01, CHEMICAL INS LTD.) Was used to measure the pH of the in vivo endometrium.

The results are shown in FIG. As shown in FIG. 1, the pH of the endometrium was 6.97 from the mating to the implantation phase (5th day after mating), and no change was observed in the measured value at the initial gestational day. From this, it was determined that the state before and after the implantation of the endometrium cannot be grasped as a change in pH.

Experimental Example 2 Measurement of Endometrial Potential Difference In vivo endometrial potential difference (mV) was measured every day using ICR mice (CLEA Japan). The mouse was opened under anesthesia, an antimony electrode was inserted into the uterine cavity from the vagina, and the in vivo using a laboratory precision digital pH / mV meter (MODEL: CL-9D01, CHEMICAL INS Co., LTD.) The potential difference of the endometrium was measured.

The results are shown in FIG. As shown in FIG. 2, a change was observed in the potential difference of the endometrium from ovulation (1.5 days after mating) to the implantation period (3.5-5.5 days after mating). From this, it was determined that there is a possibility that the state of the endometrium before and after implantation can be grasped as a change in potential difference. *

Experimental Example 3 Measurement of endometrial potential difference using human implantation failure model mouse (1) Production of experimental animal (a) Human implantation failure model mouse FEBS Lett. 2006, Vol.580, pp.2717-2722 ( According to the description of Non-Patent Document 2), a human implantation failure model mouse was prepared. The mouse implanted STAT-3 decoy consisting of double-stranded DNA designed to suppress the signal transducer and activator of transcription-3 (STAT-3) gene, one of the multifunctional transcription factors, into the uterus. This is a transiently transfected mouse. The mice have about 50% suppression of STAT-3 activity in the implantation uterus, resulting in implantation failure despite normal blood progesterone levels. The mouse is a human implantation failure model animal that well reproduces the pathology often seen in human infertility.
(B) Control Mouse A control mouse for a human implantation failure model mouse was prepared according to the description in FEBS Lett. 2006, Vol. 580, 2717-2722 (Non-patent Document 2). As a control for gene transfer, the mouse is a mouse that has been gene transferred as a scramble decoy that is a double-stranded DNA having the same length as the STAT-3 decoy and that does not bind to a specific gene sequence. After gene transfer, it has been confirmed that this gene transfer does not affect pregnancy in terms of normal implantation, maintenance of pregnancy, parturition, number of pups, birth weight, etc. (Nakamura, H. et. al., Mol. Hum. Reprod. 2003, 9: 603-609.).

(2) Measurement of the potential difference of the endometrium Using the human implantation failure model mouse and the control mouse prepared above, the potential difference of the endometrium immediately before the implantation phase is measured, and the potential difference of the in vivo endometrium We examined whether the parameters can evaluate uterine implantation ability prospectively. Specifically, the gene transfer is carried out 1.5 days after mating, and the potential difference of the in vivo endometrium immediately before the implantation (2.5 days after mating), that is, immediately before the implantation period is described in Experimental Example 2. According to the method, measurement was made in human implantation failure model mice and control mice for comparison.

The results are shown in FIG. As shown in FIG. 3, it was confirmed that the endometrial potential difference of the human implantation failure model mouse was significantly higher than that of the control mouse. From this, it was shown that when the uterine implantation ability is not appropriate, the potential difference of the in vivo endometrium increases significantly. From this result, it was suggested that the potential difference of the uterus in vivo can be a parameter that can evaluate the implantation ability of the uterus in a forward view.

Experimental Example 4 Measurement of vaginal impedance using a human implantation failure model mouse By measuring the impedance of the vaginal mucosa (AC electrical resistance value) in a rat, it is possible to determine the proestrus, that is, the optimal mating period. Known (Non-Patent Document 3: Masao Furuto et al., “Determining the appropriate mating time of F344 rats by vaginal impedance method”, Experimental Animal Technology, 22 (2), 82-85, 1987) The “IMPEDANCE CHECKER FOR RATS MK-11” for rats is sold. The vaginal impedance method is a method for determining a suitable time for mating from a phenomenon in which impedance rises in the pre-estrus period. However, it is not known whether the endometrial implantation ability can be evaluated by the vaginal impedance method.

Using the human implantation failure model mouse and the control mouse prepared in Experimental Example 3, the AC electrical resistance value (vaginal impedance) of the vaginal mucosa after mating was measured every day in the early stage of pregnancy and compared.

FIG. 4 (A) shows the results of tracking changes in vaginal impedance in the early stage of pregnancy for untreated mice over time. FIG. 4 (B) shows the results of examining vaginal mucosal impedance on the 2.5th day after mating, which is just before the implantation period, in human implantation failure model mice and control mice.

As shown in FIG. 4 (A), in the untreated mice, the impedance tends to decrease as the number of days of pregnancy progresses from the early pregnancy stage to the implantation stage (3.5-5.5 days after mating). Admitted. Further, as shown in FIG. 4 (B), it was confirmed that the vaginal impedance of the human implantation failure model mouse was significantly higher than that of the control mouse at 2.5 days after mating immediately before the implantation period. It was.

It was confirmed that the vaginal impedance showed a significantly high value when the uterine implantation ability was not appropriate. This suggests that the vaginal impedance can be a parameter that can evaluate the implantation ability of the uterus in a forward view.

From these results, the potential difference of the endometrium in the living body or the impedance of the endometrium or vaginal mucosa is measured, and the value is used as an index to evaluate the implantation ability of the endometrium in a forward view. It was suggested that it can be reflected in the treatment policy for each menstrual cycle.

∙ Many infertility is not an irreversible condition like a gene-deficient mouse, but is a condition that is temporarily out of balance, so it can be said that it is a treatable condition. Therefore, a forward-looking diagnosis for each menstrual cycle and a treatment adapted thereto are effective. If the uterine implantation ability can be measured in real time in a forward view, it can be reflected in infertility treatment. Specifically, if it is determined that the implantation ability of the uterus is good (the preparation for implantation of the uterus is sufficient) as a result of the measurement, an embryo transfer using a fresh embryo or a cryopreserved embryo is performed. If it is determined that the uterine implantability is poor (the uterus is not ready for implantation), the cycle is cryopreserved without embryo transfer, and no embryo transfer is performed during that cycle. . By performing embryo transfer at a cycle determined to be suitable for uterine implantation, it is possible to provide highly efficient infertility treatment. In other words, since wasteful embryo transfer is reduced, the number of ovarian overstimulations and egg collections that have been repeatedly performed can be reduced.

DESCRIPTION OF SYMBOLS 1 Uterine implantation ability measuring apparatus 2 Electrode 6 Control apparatus 7 Output apparatus 10 Impedance measuring instrument

Claims (10)

A method of measuring the endometrial implantation ability of a subject using as an index at least one selected from the group consisting of an endometrial potential difference obtained from the subject, endometrial impedance, and vaginal mucosal impedance. The method of claim 1, comprising the following steps:
(A) At least one value (test value) selected from the group consisting of an endometrial potential difference obtained from the subject, endometrial impedance, and vaginal mucosal impedance is used for the above test for a fertile woman. Contrasting with at least one value (control value) selected from the group consisting of endometrial potential difference corresponding to the value, endometrial impedance, and vaginal mucosal impedance, and (b) the test value corresponds to it. If the test value is higher than the control value, the subject's implantation ability is determined to be poor, and if the test value is the same or lower than the corresponding control value, the subject's implantation ability is determined to be good. Step to determine. The method of claim 1, comprising the following steps:
(A ′) a step of comparing at least one value selected from the group consisting of an endometrial potential difference obtained from a subject, endometrial impedance, and vaginal mucosal impedance (test value) with a corresponding threshold value. And (b ′) the subject's implantation ability is determined to be poor when the test value is higher than the corresponding threshold value, and the subject's implantation ability is determined to be good when the test value is equal to or lower than the threshold value. Process. The method according to claim 2 or 3, further comprising the following steps:
(C) A step of determining that embryo transfer is performed on a subject in the menstrual cycle determined to have good implantation ability. An apparatus for measuring the implantation ability of a subject's endometrium,
An electrode capable of contacting the endometrium or vaginal mucosa epithelium of the subject;
Measurement to measure the potential difference of the endometrium generated at the interface between the electrode and the endometrium, or the endometrial impedance generated between the electrode and the endometrium or vaginal mucosa epithelium, or vaginal mucosa impedance Means,
Measuring means for measuring the implantation ability of the subject's endometrium, using as an index at least one selected from the group consisting of a potential difference of the endometrium obtained from the subject, endometrial impedance, and vaginal mucosa impedance Equipment provided. The measurement means has at least one value (test value) selected from the group consisting of an endometrial potential difference obtained from a subject, endometrial impedance, and vaginal mucosal impedance, a predetermined threshold value corresponding thereto, Alternatively, at least one value selected from the group consisting of an endometrial potential difference, endometrial impedance, and vaginal mucosal impedance corresponding to the test value for a fertile woman measured in advance (control value) Comparison means to compare with)
As a result of the comparison by the comparison means, when the test value is higher than the corresponding threshold value or control value, the subject's implantation ability in the menstrual cycle is determined to be poor, and the test value is the corresponding threshold value or control value. The apparatus according to claim 5, further comprising: a determination unit that determines that the subject's implantation ability in the menstrual cycle is good when they are the same or lower. The apparatus according to claim 5 or 6, further comprising output means for outputting the endometrial implantation ability of the subject obtained by the measurement means. A method of operating a device for measuring the implantation ability of a subject's endometrium, comprising an electrode placed on the subject's endometrium or vaginal mucosal epithelium,
Measuring the endometrial potential difference, endometrial impedance, or vaginal mucosal impedance based on the potential generated in the endometrium or vaginal mucosal epithelium of the subject measured by contact with the electrode;
Measuring the implantation ability of the subject's endometrium using as an index at least one selected from the group consisting of the measured potential difference of the endometrium of the subject, endometrial impedance, and vaginal mucosal impedance How the device works. At least one value (test value) selected from the group consisting of the measured potential difference of the endometrium of the subject, endometrial impedance, and vaginal mucosa impedance, and a predetermined threshold corresponding thereto, or previously measured Comparison of at least one value (control value) selected from the group consisting of endometrial potential difference, endometrial impedance, and vaginal mucosal impedance corresponding to the above test values for a fertile woman And a process of
When the test value is higher than the corresponding threshold value or control value, the subject's implantation ability is determined to be poor in the menstrual cycle, and the test value is the same or lower than the corresponding threshold value or control value. The method according to claim 8, further comprising: determining that the subject's implantation ability in the menstrual cycle is good. The method for operating the apparatus according to claim 9, further comprising a step of outputting the measured endometrial implantation ability of the subject.

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