Unexplained infertility: evaluation of the luteal phase; results of the National Center for Infertility Research at Michigan

Overview of infertility

Having a child is an innate trait in animals, including humans, and is required for the continued existence of all animal species. Therefore, for most women, the inability to conceive or to do so in a timely fashion - termed infertility - to enable the continuation of the family line can be emotionally distressing. The definition of infertility is controversial because of its separation into primary and secondary. This is further complicated by the loosely used term subfertility, which relates to couples who have reduced ability because they take longer than the natural time to conceive, as opposed to those who are infertile and are entirely unable to conceive after 6 to 12 months, depending on age. Infertility evaluation requires a thorough male and female history, physical examination of both partners, and targeted investigation to determine the cause of infertility in a particular couple. Various treatments apply to infertile couples depending on the age of the female partner, the results of investigations, the reason for infertility, the presence of inheritance of abnormal genes, the pregnancy rates the couple is happy with, the resources available, how desperate the couple is to achieve a live birth, and how much they want to commit to treatment. Infertility treatment could include counseling and expectant management only, intrauterine insemination in a natural or stimulated cycle, and IVF and or ICSI. Men with azoospermia will need surgical options to retrieve sperm for IVF/ ICSI, but rarely for IUI. This review overviews infertility's etiology, diagnosis, investigations, and treatment.

A novel way of regression of pregnant corpus luteum during parturition in mice: The ferroptosis associated with NCOA4-mediated ferritinophagy

Numerous studies have shown that inappropriate regression of corpus luteum would lead to adverse pregnancy outcomes during gestation. However, the detailed mechanisms and types of programmed cell death involved in the regression of pregnant corpus luteum are largely unknown. Here, we investigated whether ferroptosis and ferritinophagy were involved in luteal regression during parturition in mice and related mechanisms. The results showed that ferroptosis and ferritinophagy were both involved in luteal regression during mice peri-parturition in vivo. Erastin (ferroptosis agonist) treatment significantly accelerated luteal regression and induced premature labor in pregnant mice. PGF2α treatment induced the ferroptosis and ferritinophagy of luteal cells in vitro. Nevertheless, inhibition or promotion of ferroptosis significantly altered the states of PGF2α-induced luteal cell viability and ferroptosis. Furthermore, inhibition of autophagy (3-methyladenine co-treatment) alleviated PGF2α-induced ferritinophagy and ferroptosis of luteal cells, and knockdown of NCOA4 reduced the degradation of FTH1 and the level of ferroptosis of luteal cells induced by PGF2α. In summary, our current data demonstrated that the ferroptosis associated with NCOA4-mediated ferritinophagy was a novel way of luteal regression during peri-parturition in mice. Targeting ferroptosis in the corpus luteum may be a therapeutic strategy for preventing luteal insufficiency in the future.

Luteal Phase Defects and Progesterone Supplementation

Importance

Luteal phase defects (LPDs), or an insufficiency of progesterone production during the luteal phase of the menstrual cycle, have been identified as a potential cause of recurrent pregnancy loss (RPL), but its exact contribution to RPL is not well-defined. In addition, the role of exogenous progesterone supplementation during pregnancy remains controversial.

Objective

The goal of this review is to provide an updated, evidence-based summary of LPD, including prevalence and potential pathophysiologic mechanisms, and to explore the current controversies regarding progesterone supplementation for management and treatment of RPL.

Evidence Acquisition

A literature review identified relevant research using a PubMed search, Cochrane summaries, review articles, textbook chapters, databases, and society guidelines.

Results

Endogenous progesterone plays a crucial role in the first trimester of pregnancy, and therefore, insufficiency may contribute to RPL. However, the precise relationship between LPD and RPL remains unclear. Luteal phase defect is primarily a clinical diagnosis based on a luteal phase less than 10 days. Although there may be a possibility of incorporating a combined clinical and biochemical approach in defining LPD, the current lack of validated diagnostic criteria creates a challenge for its routine incorporation in the workup of infertility. Moreover, no treatment modality has demonstrated efficacy in improving fertility outcomes for LPD patients, including progesterone supplementation, whose inconsistent data do not sufficiently support its routine use, despite its minimal risk. It is imperative that women diagnosed with LPD should be worked up for other potential conditions that may contribute to a shortened luteal phase. Future work needs to focus on identifying a reproducible diagnostic test for LPD to guide treatment.

Conclusions and Relevance

Currently, the perceived relationship between LPD and RPL is challenged by conflicting data. Therefore, patients with an abnormal luteal phase should undergo a thorough workup to address any other potential etiologies. Although supplemental progesterone is commonly utilized for treatment of LPD and RPL, inconsistent supporting data call for exogenous hormone therapy to be only used in a research setting or after a thorough discussion of its shortcomings.

Diagnosis and treatment of luteal phase deficiency: a committee opinion

Luteal phase deficiency (LPD) is a clinical diagnosis associated with an abnormal luteal phase length of ≤10 days. Potential etiologies of LPD include inadequate progesterone duration, inadequate progesterone levels, or endometrial progesterone resistance. LPD has not only been described in association with medical conditions but also in fertile, normally menstruating women. Although progesterone is important for the process of implantation and early embryonic development, LPD has not been proven to be an independent entity causing infertility or recurrent pregnancy loss. Controversy exists regarding the multiple proposed measures for diagnosing LPD and, assuming it can be diagnosed accurately, whether treatment improves outcomes. This document replaces the document entitled "Current clinical irrelevance of luteal phase deficiency: a committee opinion," last published in 2015 (Fertil Steril 2015;103:e27-e32).

Effect of the anterior uterocervical angle in unexplained infertility: a prospective cohort study

OBJECTIVE

The present study aimed to evaluate an anatomical region, the anterior uterocervical angle (UCA), to determine whether it plays a role in unexplained infertility.

METHODS

In this prospective, cross-sectional study, unexplained infertile and healthy fertile (controls) women were compared. The longitudinal and transverse axes of the uterine cervix and uterine corpus were measured by transvaginal ultrasonography. The UCA was determined as the angle between two lines. One line was drawn between the internal and the external os, and the other was drawn through the internal cervical os and was parallel to the lower side of the front part of the uterine wall in the internal os. Demographic characteristics and uterocervical ultrasonographic measurements were compared between the two groups.

RESULTS

Eighty participants, aged from 20 to 35 years, were enrolled (unexplained infertile [n = 30] and healthy fertile women [n = 50)]. The mean lengths of the uterine corpus longitudinal axis, uterine corpus transverse axis, and uterine cervix longitudinal axis were similar between the groups. The mean UCA was significantly higher in healthy fertile women (131.9 ± 22.9 degrees) than in women with unexplained infertility (114.2 ± 17.3 degrees).

CONCLUSION

The present study shows that a narrow anterior UCA is associated with unexplained infertility.

Menstrual Cycle in Women Who Co-use Marijuana and Tobacco

OBJECTIVE

Marijuana is the most commonly used illicit drug in the United States and co-use with tobacco is increasing. Preliminary studies have indicated that marijuana may suppress luteinizing hormone (LH) or shorten the luteal phase. Although the literature is mixed, these sex hormones may play a role in smoking cessation outcomes. This secondary subgroup analysis aims to explore the menstrual cycle of females who co-use marijuana and tobacco compared with females who only use tobacco in a sample of tobacco treatment-seeking individuals.

METHODS

Female participants, aged 18 to 50 years, who self-reported regular menstrual cycles and co-use of marijuana and tobacco were matched 1:3 by age to participants who only use tobacco. Length of the follicular and luteal phases was determined using First Response Urine LH tests. Wilcoxon 2-sample t tests were used to determine differences in phase lengths between groups.

RESULTS

Thirteen women who co-use marijuana and tobacco, and 39 women who only use tobacco were included in this analysis. Overall, participants were 37.3 ± 8.0 (SD) years of age, mostly Caucasian (67%), and smoked 12.6 ± 5.2 (SD) cigarettes per day. The luteal phase length among participants who co-use marijuana and tobacco (11.4 days ± 2.2 [SD]) was significantly shorter than among participants who only use tobacco (16.8 days ± 11.3 [SD]; P = 0.002). No differences were found in follicular phase length or menstrual cycle length.

CONCLUSIONS

These data suggest that females who co-use marijuana and tobacco may have a shortened luteal phase in comparison with females who only use tobacco. Further studies are needed to better understand how marijuana use may impact the menstrual cycle and affect smoking outcomes.

Menstrual Disruption with Exercise Is Not Linked to an Energy Availability Threshold

INTRODUCTION

Chronic reductions in energy availability (EA) suppress reproductive function. A particular calculation of EA quantifies the dietary energy remaining after exercise for all physiological functions. Reductions in luteinizing hormone pulse frequency have been demonstrated when EA using this calculation is <30 kcal·kg·fat-free mass (ffm)·d.

PURPOSE

We determined whether menstrual disturbances (MD) are induced when EA is <30 kcal·kg ffm·d.

METHODS

Thirty-five sedentary, ovulatory women age 18 to 24 yr (weight, 59.0 ± 0.8 kg; body mass index, 21.8 ± 0.4 kg·m) completed a diet and exercise intervention over three menstrual cycles. Participants were randomized to groups that varied in the magnitude of negative energy balance created by the combination of exercise and energy restriction. Menstrual disturbances were determined using daily urinary estrone-1-glucuronide and pregnanediol glucuronide, midcycle luteinizing hormone, and menstrual calendars. In a secondary analysis, we calculated EA from energy balance data and tested the association of EA with MD.

RESULTS

A generalized linear mixed-effects model showed that the likelihood of a MD decreased by 9% for each unit increase in EA (odds ratio, 0.91; 95% confidence interval, 0.84-0.98; P = 0.010). No specific value of EA emerged as a threshold below which MD were induced. When participants were partitioned into EA tertile groups (low EA, 23.4-34.1; n = 11; moderate EA, 34.9-40.7; n = 12, and high EA, 41.2-50.1; n = 12 [kcal·kg ffm·d]), estrone-1-glucuronide (P < 0.001), pregnanediol glucuronide (P < 0.001), and luteal phase length (P = 0.031) decreased significantly, independent of tertile.

CONCLUSIONS

These findings do not support that a threshold of EA exists below which MD are induced but do suggest that MD increase linearly as EA decreases. Menstrual disturbances can likely be prevented by monitoring EA using a simplified assessment of metabolic status.

Dydrogesterone: pharmacological profile and mechanism of action as luteal phase support in assisted reproduction

The pharmacological and physiological profiles of progestogens used for luteal phase support during assisted reproductive technology are likely to be important in guiding clinical choice towards the most appropriate treatment option. Various micronized progesterone formulations with differing pharmacological profiles have been investigated for several purposes. Dydrogesterone, a stereoisomer of progesterone, is available in an oral form with high oral bioavailability; it has been used to treat a variety of conditions related to progesterone deficiency since the 1960s and has recently been approved for luteal phase support as part of an assisted reproductive technology treatment. The primary objective of this review is to critically analyse the clinical implications of the pharmacological and physiological properties of dydrogesterone for its uses in luteal phase support and in early pregnancy.

Leptin as a Predictive Marker in Unexplained Infertility in North Indian Population

INTRODUCTION

According to WHO, the primary infertility in India is about 3.9% (age-standardized to 25-49 year) and 16.8% (age-standardized to 15-49 year), using the "age but no birth" definition. Several factors which affect fertility include low sperm production in men, poor egg quality and blocked fallopian tubes in women and also hormonal imbalances. Leptin plays a critical role in women's reproduction and neuroendocrine health. It is used for treating exercise-induced bone loss, eating disorders and infertility.

AIM

To evaluate the serum leptin levels in Indians and to ascertain the relationship between serum leptin levels, Unexplained Infertility (UI) and related variables [height, weight, Waist Hip Ratio (WHR), Body Mass Index (BMI)] between obese infertile, non-obese infertile and healthy subjects.

MATERIALS AND METHODS

The present case-control study was conducted at the Department of Obstetrics and Gynaecology, King George's Medical University (KGMU), Lucknow, India and funded by Department of Science and Technology, New Delhi, India. The study included 229 female participants in the age group of 18-40 years (120 cases and 109 controls) who were randomly selected. The blood samples were collected from the Infertility Clinic, Queen Mary's Hospital, KGMU, Lucknow, India. All the participants underwent complete physical examination. Initially, the participants were categorized into fertile and infertile groups, they were further divided on the basis of BMI, normal (BMI- 18.5-24.5) and overweight or obese (BMI≥25). Leptin level was measured by Active Human Leptin ELISA kit and BMI of all subjects was calculated in kg/m² (weight in kg and height in m).

RESULTS

A highly positive linear correlation (R=0.754, p<0.001) was found between BMI and serum leptin in unexplained infertile women, which indicates a strong relationship between BMI and serum leptin. The variation in serum leptin is explained by the independent variable, BMI. There was a partial positive linear correlation between BMI and serum leptin in the control group. Statistically there was no significant correlation (R=0.109, p=0.258) between BMI and serum leptin in the control group.

CONCLUSION

The present study clearly demonstrates that level of leptin is higher in unexplained infertile than in the fertile group, and also shows that a strong relationship exists between BMI and serum leptin in the obese group. Serum leptin level was significantly higher in obese than non-obese subjects. Thus, leptin is an important factor for normal reproductive function. Obesity, the main cause of infertility may be controlled by regulating the leptin concentration.

Combination therapeutic options in the treatment of the luteal phase deficiency

Luteal phase deficiency (LPD) is described as a condition of insufficient progesterone exposure to maintain a regular secretory endometrium and allow for normal embryo implantation and growth. There is evidence that both follicular and luteal phase abnormalities can result in LPD cycles. The aim of this randomized prospective noncomparative study is to evaluate the effectiveness of combination therapy in patients with LPD. This prospective study included 35 women of the reproductive age. They were diagnosed with the LPD with sonographically and laboratory-verified methods. The age of patients was 36 ± 0.46 years. The results of the study sonographically demonstrated an increase in the diameter of the corpus luteum from 1.36 ± 0.32 (initially) to 2.16 ± 0.21 mm after combination therapy. In addition, there was a statistically significant increase in the level of estrogens and progesterone in the corresponding phases of the menstrual cycle. Thus, the combination therapy for patients with LPD contributes to the recovery of cyclic events in the hypothalamic-pituitary-gonadal system, which determines the restoration of the endocrine function of the ovaries and promotes adequate secretory rearrangement of the endometrium in women of reproductive age.

Dydrogesterone use in early pregnancy

Successful oocyte implantation and a favorable pregnancy outcome rely on optimal progesterone levels. Therefore, progesterone deficiencies associated with infertility and miscarriage have commonly been treated with progestogens that mimic the activity of progesterone. Among those is dydrogesterone, an oral retrosteroid with a structure closely related to that of progesterone yet with a greater bioavailability and higher selectivity for the progesterone receptor. This review describes the efficacy of dydrogesterone for the treatment of threatened and recurrent miscarriage, and infertility due to luteal phase insufficiency. Data from clinical trials evaluating dydrogesterone in assisted reproductive technology are also discussed. Prospective clinical trials, systematic reviews and meta-analyses have demonstrated that dydrogesterone significantly improves pregnancy outcomes in women with threatened miscarriage or with a history of miscarriage. Although this is not yet a registered indication, dydrogesterone was as effective as vaginal micronized progesterone for luteal phase support in the setting of assisted reproductive technology. The safety and tolerability of dydrogesterone treatment in pregnant women are also briefly addressed and the data support a well-established and favorable benefit-risk profile.

Progesterone and the luteal phase: a requisite to reproduction

Progesterone production from the corpus luteum is critical for natural reproduction. Progesterone supplementation seems to be an important aspect of any assisted reproductive technology treatment. Luteal phase deficiency in natural cycles is a plausible cause of infertility and pregnancy loss, though there is no adequate diagnostic test. This article describes the normal luteal phase of the menstrual cycle, investigates the controversy surrounding luteal phase deficiency, and presents the current literature for progesterone supplementation during assisted reproductive technologies.

Return of ovulation and menses in postpartum nonlactating women: a systematic review

OBJECTIVES

To estimate, from the literature, when nonlactating postpartum women regain fertility.

DATA SOURCES

We searched PubMed and Cochrane Library databases for all articles (in all languages) published in peer-reviewed journals from database inception through May 2010 for evidence related to the return of ovulation and menses in nonlactating postpartum women. Search terms included "Fertility" (Mesh) OR "Ovulation" (Mesh) OR "Ovulation Detection" (Mesh) OR "Ovulation Prediction" (Mesh) OR fertility OR ovulat* AND "Postpartum Period" (Mesh) OR postpartum OR puerperium AND Human AND Female.

METHODS OF STUDY SELECTION

We included articles assessing nonlactating women's first ovulation postpartum. Studies in which women breastfed for any period of time or in whom lactation was suppressed with medications were excluded.

TABULATION, INTEGRATION AND RESULTS

We identified 1,623 articles; six articles reported four studies met our inclusion criteria. In three studies utilizing urinary pregnanediol levels to measure ovulation, mean day of first ovulation ranged from 45 to 94 days postpartum; 20%-71% of first menses were preceded by ovulation and 0%-60% of these ovulations were potentially fertile. In one study that used basal body temperature to measure ovulation, mean first ovulation occurred on day 74 postpartum; 33% of first menses were preceded by ovulation and 70% of these were potentially fertile.

CONCLUSION

Most nonlactating women will not ovulate until 6 weeks postpartum. A small number of women will ovulate earlier, potentially putting them at risk for pregnancy sooner, although the fertility of these early ovulations is not well-established. The potential risk of pregnancy soon after delivery underscores the importance of initiating postpartum contraception in a timely fashion.

Serum leptin level in women with unexplained infertility

INTRODUCTION

The aim of this study was to compare serum levels of leptin in women with unexplained infertility with fertile subjects.

MATERIAL AND METHOD

Serum leptin levels of 27 infertile and 30 fertile women on day 3 of the menstrual cycle were assessed and compared in this prospective age and body mass index (BMI) comparable controlled study.

RESULTS

The mean age in the infertile group was 29.3 (range, 23-38), while this figure was 28.9 (range, 19-39) in the fertile group; the mean BMIs were 24.5 (range, 20.6-27.8) and 25.0 (range, 21.8-28.7), respectively. The mean serum leptin level was significantly higher in women with unexplained infertility compared with fertile subjects. Considering normal weight subjects, mean serum leptin levels were increased significantly in the unexplained infertile group compared with the fertile group (7.2 (range, 4.3-10.4) versus 3.5 (range, 1.9-6.2)ng/ml, respectively; p<0.0001, Mann-Whitney U-test). The significant increase in serum leptin levels was observed also in overweight patients (6.8 (range, 1.3-5.2) versus 3.3 (range, 4.2-8.9)ng/ml, respectively; p<0.0001, Mann-Whitney U-test).

CONCLUSION

A significant difference in serum leptin levels between unexplained infertile and fertile women suggests that this cytokine may be involved in pathophysiology of unexplained infertility.

Luteal phase defect: myth or reality

Although the diagnosis of luteal phase defect (LPD) has been described convincingly in the research setting, it remains a controversial clinical entity. Apart from many uncertainties that surround the diagnosis of LPD, there is no convincing evidence that LPD is associated with infertility and recurrent abortion. Once diagnosed, the treatment options are empiric and include those that are recommended for unexplained infertility. The efforts to diagnose LPD in patients who have infertility or recurrent abortion are not justified.

Characterizing the endometrium in unexplained and tubal factor infertility: A multiparametric investigation

OBJECTIVE

To characterize endometrial development in unexplained and tubal factor infertility.

DESIGN

Prospective study of 20 women with unexplained infertility, 22 with tubal factor infertility, and 21 fertile controls in the midproliferative, periovulatory, and midluteal phases of the menstrual cycle.

SETTING

Reproductive Medicine Department of St. Mary's Hospital, Manchester, United Kingdom.

PATIENT(S)

Women awaiting assisted conception.

INVESTIGATION(S)

Serum hormone assays, transvaginal ultrasound, Doppler, and midluteal endometrial biopsies.

MAIN OUTCOME MEASURE(S)

Serum levels of E2, P, and LH, endometrial ultrasound morphometry, uterine and subendometrial artery Doppler, and endometrial histology and biochemistry.

RESULT(S)

Women with unexplained infertility demonstrated significantly reduced uterine artery flow velocity in all phases, significantly elevated uterine and subendometrial artery impedance in the periovulatory and midluteal phases, and significantly reduced endometrial texture in the midproliferative phase. Women with tubal factor infertility demonstrated significantly reduced uterine artery flow velocity, without a concomitant increase in impedance, and significantly greater expression of endometrial glandular and luminal keratan sulphate.

CONCLUSION(S)

Unexplained infertility is associated with a profound impairment of endometrial perfusion that might be amenable to treatment by perfusion enhancers. Tubal factor infertility is associated with endometrial developmental defects that might be corrected by salpingectomy. Endometrial ultrasound and Doppler studies are likely to become a vital tool in the investigation of infertility.

Present concept of unexplained infertility

Despite improvements in both diagnostic assessment and treatment of infertile couples, many couples still have no explanation for their infertility. Unexplained infertility (the failure to conceive of a couple in whom no definitive cause for infertility can be found) has an incidence of 10-20% in all infertile couples. The incidence varies with the population studied and with the criteria used. Unexplained infertility is not an absolute condition but rather a relative inability to conceive, and many of these couples may conceive without treatment. The treatment options for unexplained infertility are several and the treatment results are promising. Expectant management can be recommended if the woman is under 28-30 years of age and the infertility duration is less than 2-3 years. In vitro fertilization (IVF) has revolutionized the treatment of infertile couples, as well as profoundly increasing the basic understanding of human reproduction. IVF can be used as both a diagnostic and a therapeutic tool in couples with unexplained infertility. The pregnancy rates with IVF are good, at 40% per treatment cycle. In addition, the outcome of pregnancies among women with unexplained infertility is generally comparable to that of spontaneous and other pregnancies using assisted reproductive technologies.

A successful pregnancy following SEM fine tuning of hormonal priming

BACKGROUND: Manipulation of the uterine epithelium utilising standard dose exogenous oestrogen (E2) and progesterone (P4) has been shown to achieve a mature secretory morphological response. However, in an in vitro fertilisation (IVF) setting, frozen embryo transfer (ET) has had a low success rate. We propose that in patients with previously failed ET attempts, the uterine epithelium can be directly visualised by biopsy and Scanning Electron Microscopy (SEM) and that with an individualised fine tuning of the hormone supplementation regime, based on the SEM examination of sequential uterine biopsies, it is possible to provide a uterine environment conducive to successful ET. METHODS: A 47 year old women was chosen for endometrial biopsy, histopathological dating and endometrial observation utilising SEM to determine the integrity of her secretory uterine epithelium because of her age and several previously failed attempts at frozen ET. Exogenous E2 and P4 supplementation was administered in modified doses according to the SEM result, in consecutive cycles until the epithelial response appeared satisfactory for potential implantation. RESULTS: This case study demonstrates the dramatic change in epithelial characteristics that can be achieved as a response to these altered doses of E2 and P4. The uterine morphology changed from a hypotrophic to a mature, receptive epithelium such that ET resulted in the birth of healthy twin boys. CONCLUSION: The comparison between the consecutive biopsies in direct response to the SEM analysis and tailored modification of E2 and P4 dose clearly demonstrates, in this case, the effectiveness of individual morphological monitoring to maximise the successful outcome of ET.

The fimbrio-ovarian relation and its role on ovum picking in unexplained infertility: the fimbrio-ovarian accessibility tests

OBJECTIVE

To study the ovum pickup mechanism and the fimbrio-ovarian relation in fertile women and cases of unexplained infertility and to design a method for investigation and anticipation of the state of ovum pickup.

DESIGN

Prospective clinical study.

SETTING

Department of Obstetrics and gynecology Kasr El Aini Hospital, Cairo University, Egypt.

PATIENTS

Fifty fertile and 25 cases of unexplained infertility.

INTERVENTIONS

In all of cases the fimbrio-ovarian relation is studied by determining the length of the free ovarian border between the ovarian ligament and the fimbria ovarica that contains the corpus luteum (the ovulation border), the site of ovulation on that border and the length of the fimbria ovarica. It is also determined by a simple test "The fimbrio-ovarian accessibility test." The fimbriae are held by non-traumatizing grasper and their ability to reach and/or to cover the ovulation site are taken as a prove for successful ovum pickup. In addition, cases having suspected failed ovum picking are treated by controlled superovulation, also by drilling of the ovary at an accessible site to the fimbria ovarica and by freeing short fimbria ovarica with or without its advancement on the ovulation border.

RESULTS

The ovulation site is found to be usually accessible to the fimbrial end of the tube (94%) in the fertile cases and not accessible (92%) in the infertile cases. Correction of the fimbrio-ovarian relation in the infertile cases was associated with a cumulative ongoing pregnancy rate of 68%.

CONCLUSION

Failed ovum pickup should be considered one of the important causes of unexplained infertility. The suggested "fimbrio-ovarian accessibility" test may be useful for the elucidation of the state of ovum pickup in infertile cases. Correction of the fimbrio-ovarian relation, to make ovum pickup possible, should be considered a method for treating such cases.

Endometrial leukemia inhibitory factor (LIF) as a possible cause of unexplained infertility and multiple failures of implantation

PROBLEM

The possible role of leukemia inhibiting factor (LIF) in unexplained infertility and multiple failures of implantation (MFI) was evaluated.

METHOD OF STUDY

By a specific and sensitive enzyme-linked immunosorbent assay (ELISA), the in vitro endometrial LIF secretion by explant cultures from women with unexplained infertility (n = 32) was examined. Endometrial samples were obtained on either days 8-11 of the proliferative phase or days 18-21 of the secretory phase. In some subjects (n = 11) an endometrial biopsy was performed twice, both in the proliferative and in the secretory phase of the cycle. The control group consisted of fertile women (n = 17).

RESULTS

In fertile women the endometrial LIF secretion was 2.2 times higher in the secretory phase samples than in the proliferative phase samples (mean +/- SEM, 3259 +/- 314 pg in the proliferative phase vs. 7726 +/- 1192 in the secretory phase; P < 0.05). In contrast, infertile women exhibited no such elevation of cytokine production. Moreover, in infertile women with MFI the level of LIF in the secretory phase demonstrated the tendency to decrease (mean +/- SEM, 4953 +/- 1125 pg vs. 2162 +/- 541 pg; P > 0.05). When the amount of cytokine secretion was compared on the same day of the cycle between the two groups of women, the LIF production in fertile women on days 18-21 of the menstrual cycle was 3.5 times greater than in the infertile women with MFI and 2.2 times greater than in women without MFI (P < 0.01 and P < 0.05, respectively). On days 8-11 of the cycle, the level of LIF in these groups did not differ significantly, however, in infertile women the range of distribution of cytokine was largely varied, demonstrating the highest amplitude of variations in subjects with MFI. Analyses of the data for women to whom LIF was examined in both phases of the cycle showed that some subjects (27%) exhibited an elevated amount of LIF in the secretory phase of the cycle. This suggests that in these cases the endometrial factor(s) may be irrelevant to infertility.

CONCLUSION

In the majority of infertile women there is a deregulation of LIF production in the endometrium during both the proliferative and the secretory phases of the cycle. The dysfunction of cytokine production is more profound in patients with MFI. The deregulation of endometrial LIF secretion throughout the menstrual cycle may be a possible cause of unexplained infertility and repetitive failures of implantation.