Contemporary Management of Unexplained Infertility

The knowledge domain and emerging trends in the infertility field: A 67-year retrospective study

Infertility is a significant problem influencing many couples. Our purpose was to assess the field of infertility in Obstetrics and Gynecology from 1955 to 2022 reviewing 3575 documents found in the Web of Science database. Most articles were in the areas of Reproductive Biology, Fertility, Endometriosis & Hysterectomy, and Chromosome Disorders. We found publication has increased dramatically since 1989. Agarwal, Thomas, and Sharma; United States, England, and Canada; Fertility and Sterility, Human Reproduction, and AJOG were the most-cited authors, countries, and journals, respectively. We discovered five substantive clusters: male infertility factors, female infertility factors, causes and treatment of infertility, the consequence of infertility, and assisted reproductive techniques. Using bibliometric review (Co-citation analysis) six research areas were found: semen analysis and sperm morphology, regional differences in the psychological effects of infertility, unexplained infertility, endometriosis, diagnosis and treatment of infertility, and polycystic ovary syndrome. Despite advances in understanding infertility, further research is needed.

Maternal body mass index associates with blastocyst euploidy and live birth rates: the tip of an iceberg?

RESEARCH QUESTION

Does maternal preconceptional body mass index (BMI) associate with mean blastocyst euploidy rate (m-ER) per patient and live birth rate (LBR) after vitrified-warmed euploid single embryo transfer (SET)?

DESIGN

Observational study conducted between April 2013 and March 2020 at a private IVF clinic, involving 1811 Caucasian women undergoing trophectoderm biopsy and comprehensive chromosome testing. The outcomes of 1125 first vitrified-warmed euploid SET were also analysed. Patients were clustered as normal weight (BMI 18.5-25; n = 1392 performing 859 SET), underweight (BMI <18.5; n = 160 performing 112 SET) and overweight (BMI >25; n = 259 performing 154 SET). m-ER per patient was the primary outcome. The secondary outcomes were all clinical outcomes per euploid SET. All data were adjusted for confounders through regression analyses.

RESULTS

The m-ER per patient decreases as maternal BMI increases from 17 up to 22-23 before reaching a plateau. A linear regression adjusted for maternal age confirmed this moderate association (unstandardized coefficient B: -0.6%, 95% confidence interval [CI]: -1.1 to -0.1%, P = 0.02). All clinical outcomes were similar between normal weight and underweight women. Overweight women, instead, showed higher miscarriage rate per clinical pregnancy (n = 20/75, 26.7% versus n = 67/461, 14.5%; odds ratio [OR] adjusted for blastocyst quality and day of full blastulation: 2.0, 95% CI: 1.1-3.6, P = 0.01) and lower LBR per SET (n = 55/154, 35.7% versus n = 388/859, 45.2%; OR adjusted for blastocyst quality and day of full blastulation: 0.67, 95% CI: 0.46-0.96, P = 0.03).

CONCLUSION

These data indicate a need for future research on more sensitive metrics to assess body fat mass and distribution, as well as on the mechanisms leading to lipotoxicity, thereby impairing embryo competence and/or endometrial receptivity. Overweight women should be informed of their higher risk for miscarriage and, whenever possible, encouraged to lose weight, especially before transfer.

Endometrial Factor in Unexplained Infertility and Recurrent Implantation Failure

Unexplained infertility (UI) and recurrent implantation failure (RIF) are diagnoses based on failed pregnancy attempts within current infertility treatment models. Both diagnoses are made when fertility is unexplained based on current diagnostic methods and has no clear cause; UI is diagnosed when testing is inconclusive, and RIF is diagnosed after three failed in vitro fertilization cycles. In both cases, interventions are often introduced without an understanding of the cause of the infertility, frequently leading to frustration for patients and caregivers. Here, we review evidence to support an influence of endometrial factor in patients given these poorly defined diagnoses and possible treatments targeting the endometrium to improve outcomes in these patients.

Anti-Müllerian hormone as a predictor of pregnancy in women under 35 years with unexplained infertility undergoing ICSI: a retrospective study

BACKGROUND

Anti-Müllerian hormone (AMH) is a well-established marker for the determination of ovarian reserve. However, its role in the prediction of pregnancy is still under debate. In this retrospective study, we aimed to evaluate the relationship of serum AMH levels with pregnancy rates in patients with unexplained infertility undergoing ICSI. Moreover, we compared the predictive value of AMH with that of antral follicle count (AFC).

METHODS

Records of 76 patients under 35 years of age with AMH levels between 1 and 3.5 ng/ml were examined retrospectively. Participants were divided into groups based on their AMH level and age.

RESULTS

AMH levels in women under 30 years were found significantly higher than those in women over 30 years (P=0.033). 57 of 76 patients (75%) were pregnant. Age did not have a significant effect on the pregnancy rates in the selected study group (P=0.252). On the other hand, despite the poor predictive accuracy, serum AMH was shown to have a predictive value with a cut-off point of 1.95 ng/mL. Logistic regression tests demonstrated a higher pregnancy rate (3.396 fold) with an AMH level 1.95 or above. There was no significant relationship between AFC and pregnancy.

CONCLUSIONS

AMH might have a role in the prediction of pregnancy after ICSI in patients under 35 years with unexplained infertility.

A comparison of oral versus injectable ovarian stimulation in IUI in women ≥38 years of age with decreased ovarian reserve

PURPOSE

To compare pregnancy rates of oral ovarian hyperstimulation agents (clomiphene citrate (CC) and letrozole) versus injectable agents (gonadotropins) in intrauterine insemination (IUI) in the older reproductive age group with diminished ovarian reserve.

METHODS

A retrospective cohort study was performed among 210 women 38-43 years of age undergoing IUI with controlled ovarian hyperstimulation (COH) at a single academic institution between 2009 and 2018.

RESULTS

A total of 335 IUI cycles met inclusion criteria. Gonadotropins were the most frequently used ovarian hyperstimulation agent (n = 264), followed by CC (n = 38) and letrozole (n = 33). Mean age of the cohort was 40.5 (±1.6) years (range 38-43) did not differ significantly among groups (p = 0.41). Mean AFC and number of mature follicles on day of ovulation trigger also did not differ among groups (p = 0.98, p = 0.10). Overall clinical pregnancy rate was 7.5% per cycle, and rates for CC, letrozole, and gonadotropins respectively were 5.3%, 9.1%, 7.5% per cycle (p = 0.347). There was one multiple gestation pregnancy (twins), which was in a patient stimulated with gonadotropins.

CONCLUSION

This is the first study to compare CC, letrozole, and gonadotropins in older reproductive age women with decreased ovarian reserve. The findings reveal that COH/IUI in older women with decreased ovarian reserve is a viable option (clinical pregnancy rate of 7.5% per cycle), and suggest that oral stimulation agents may be the first-line option, with letrozole having conferred the highest clinical pregnancy rate, 9.1%, which is notable given the typical poor fecundability of this population. However, larger population studies are needed to support this.

Endometrial function in women with polycystic ovary syndrome: a comprehensive review

BACKGROUND

Polycystic ovary syndrome (PCOS) is the most common cause of anovulatory infertility. An endometrial component has been suggested to contribute to subfertility and poor reproductive outcomes in affected women.

OBJECTIVE AND RATIONALE

The aim of this review was to determine whether there is sufficient evidence to support that endometrial function is altered in women with PCOS, whether clinical features of PCOS affect the endometrium, and whether there are evidence-based interventions to improve endometrial dysfunction in PCOS women.

SEARCH METHODS

An extensive literature search was performed from 1970 up to July 2020 using PubMed and Web of Science without language restriction. The search included all titles and abstracts assessing a relationship between PCOS and endometrial function, the role played by clinical and biochemical/hormonal factors related to PCOS and endometrial function, and the potential interventions aimed to improve endometrial function in women with PCOS. All published papers were included if considered relevant. Studies having a specific topic/hypothesis regarding endometrial cancer/hyperplasia in women with PCOS were excluded from the analysis.

OUTCOMES

Experimental and clinical data suggest that the endometrium differs in women with PCOS when compared to healthy controls. Clinical characteristics related to the syndrome, alone and/or in combination, may contribute to dysregulation of endometrial expression of sex hormone receptors and co-receptors, increase endometrial insulin-resistance with impaired glucose transport and utilization, and result in chronic low-grade inflammation, immune dysfunction, altered uterine vascularity, abnormal endometrial gene expression and cellular abnormalities in women with PCOS. Among several interventions to improve endometrial function in women with PCOS, to date, only lifestyle modification, metformin and bariatric surgery have the highest scientific evidence for clinical benefit.

WIDER IMPLICATIONS

Endometrial dysfunction and abnormal trophoblast invasion and placentation in PCOS women can predispose to miscarriage and pregnancy complications. Thus, patients and their health care providers should advise about these risks. Although currently no intervention can be universally recommended to reverse endometrial dysfunction in PCOS women, lifestyle modifications and metformin may improve underlying endometrial dysfunction and pregnancy outcomes in obese and/or insulin resistant patients. Bariatric surgery has shown its efficacy in severely obese PCOS patients, but a careful evaluation of the benefit/risk ratio is warranted. Large scale randomized controlled clinical trials should address these possibilities.

Hysteroscopy for Assessing Fallopian Tubal Obstruction: A Systematic Review and Diagnostic Test Accuracy Meta-analysis

OBJECTIVE

To assess the diagnostic accuracy of hysteroscopy compared with that of laparoscopic chromopertubation for the detection of fallopian tubal obstruction.

DATA SOURCES

An electronic search from inception to March 31, 2020, was performed in Medline, Scopus, EMBASE, and the Cochrane Central Register of Controlled Trials.

METHODS OF STUDY SELECTION

This diagnostic accuracy meta-analysis was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses and Synthesizing Evidence from Diagnostic Accuracy Tests recommendations. A combination of the following Medical Subject Headings terms and keywords was included in the search strategy: "hysteroscopy[MeSH]," "tubal obstruction," "tubal patency," "tubal dysfunction," and "tubal blockage." Quality assessment of the included studies was conducted using the Quality Assessment Tool for Diagnostic Accuracy Studies-2 (University of Bristol, Bristol, United Kingdom). Publication bias was evaluated by means of the Deek funnel plot asymmetry test. The following outcomes were analyzed: diagnostic odds ratio, area under hierarchical summary receiver operating characteristic and area under receiver operating characteristic curve, sensitivity, specificity, and positive and negative likelihood ratios.

TABULATION, INTEGRATION, AND RESULTS

Six studies comparing hysteroscopy with laparoscopic chromopertubation were included in the meta-analysis. After pooling all the studies, the diagnostic odds ratio was 43. The evaluated area under receiver operating characteristic curve was 0.93, correlating with high diagnostic accuracy for the index test. Sensitivity and specificity were 88% and 85%, respectively. In addition, the positive and negative likelihood ratios were 5.88 and 0.16, respectively.

CONCLUSION

Hysteroscopic techniques are highly accurate and sensitive for detecting fallopian tubal obstruction. Interventional assessment enhances diagnostic accuracy compared with observational assessment, as does the office setting compared with the operating room. Additional studies, along with a refinement of the techniques, could facilitate the widespread use of hysteroscopic techniques for the detection of fallopian tube occlusion.

Is Intracytoplasmic Sperm Injection the Solution for all in Unexplained Infertility?

Intracytoplasmic sperm injection (ICSI) was first introduced as a supplemental method to conventional in vitro fertilization (c-IVF) for couples with severe male factor infertility to overcome the poor fertilization rate, while its indications expanded in current clinical practice and gained worldwide popularity. However, ICSI is invasive and crosses all natural barriers, raising several unresolved concerns regarding procedure-dependent and procedure-independent risks, as well as the characteristic of being labor-intensive and more expensive than c-IVF. This review is aimed to draw readers' attention, to the widespread use of ICSI worldwide, with its effectiveness in different indications of infertility, especially in those with unexplained infertility, as well as the cost-effectiveness of the ICSI-for-all strategy. Also, we covered current evidence on the short- and long-term safety of children born thanks to ICSI-aided conception. Further well-designed, adequately powered, and randomized controlled clinical trials are absolutely needed to arrive at a consensus on the use of ICSI over c-IVF in different populations.