Effects of female increased body mass index on in vitro fertilization cycles outcome

When Weight Matters: How Obesity Impacts Reproductive Health and Pregnancy-A Systematic Review

PURPOSE OF REVIEW

This systematic review evaluates the impact of obesity on both male and female reproductive health, assisted reproductive technology (ART) outcomes, and pregnancy-related complications, providing a comprehensive synthesis of the evidence.

RECENT FINDINGS

Obesity is a critical factor adversely affecting reproductive health, ART success rates, and pregnancy outcomes. Recent studies indicate hormonal disruptions, metabolic syndrome, and epigenetic modifications as central mechanisms linking obesity to infertility and adverse pregnancy results. A systematic search adhering to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines included 35 studies, focusing on obesity-related reproductive outcomes. The review highlights that obesity disrupts hormonal balance, including reductions in sex hormone-binding globulin (SHBG) and testosterone levels, alongside increased insulin resistance and chronic inflammation. These mechanisms impair ovarian function, endometrial receptivity, and sperm quality, resulting in prolonged time-to-pregnancy (TTP), reduced ART success rates, and increased miscarriage risk. During pregnancy, maternal obesity elevates risks of gestational diabetes mellitus (GDM), preeclampsia, and cesarean delivery while contributing to neonatal complications, such as macrosomia and neonatal intensive care unit (NICU) admissions. The findings emphasize the dual impact of maternal and paternal obesity on offspring health, particularly through epigenetic modifications leading to intergenerational metabolic dysfunction. This review underscores the necessity of preconception weight management, individualized ART protocols, and tailored antenatal care to mitigate obesity's adverse effects on reproductive outcomes. Future research should focus on understanding male infertility mechanisms, optimizing ART interventions for individuals with obesity, and conducting longitudinal studies on the intergenerational impacts of obesity on reproductive health. This synthesis provides actionable insights to guide clinical practices and future investigations.

Impact of body mass index on peripheral and uterine immune status in the window of implantation in patients with recurrent reproductive failure

This study aimed to investigate whether maternal obesity affects the immune status of peripheral blood and endometrium in patients with recurrent reproductive failure classified according to their body mass index (BMI). A total of 228 repeated implantation failure (RIF) and 266 recurrent miscarriage (RM) patients were enrolled in the study and further subdivided into three groups according to their BMI: (i) normal weight (18.5≤ BMI <23); (ii) overweight (23≤ BMI <25); and (iii) obese (BMI ≥25). Peripheral blood and endometrium samples were collected in the mid-luteal phase before IVF treatment or natural pregnancy. Peripheral immunocytes were analyzed by flow cytometry, while uterine immune cells were subjected to immunohistochemistry. In RM patients, significantly increased peripheral helper T cells and decreased cytotoxic T cells, NK cells were observed in the obese group compared with the normal-weight group. Meanwhile, in the endometrium, the percentage of NK cell, macrophage cell, M2 macrophage cell, and Treg cell significantly reduced with increased BMI in RIF patients, and the percentage of NK cell and M2 macrophage cell significantly decreased with increased BMI in RM patients. In conclusion, obesity may cause endometrial immune disorder in recurrent reproductive failure women, but was only associated with the peripheral immune change in RM patients.

Analysis of HIF2α polymorphisms in infertile women with polycystic ovary syndrome or unexplained infertility

OBJECTIVE

To evaluate HIF2α polymorphisms and glucose metabolism in a group of women with polycystic ovary syndrome (PCOS) or unexplained infertility (UI).

PATIENTS

The infertile group (n=148) consisted of 96 women with PCOS, 52 women with UI, and176 women without infertility as a healthy control group.

INTERVENTION

We genotyped 29 single nucleotide polymorphisms (SNPs) of HIF2α by using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS)-based genotyping technology. The genetic associations were analyzed statistically.

MAIN OUTCOME MEASURES

Allele frequency, genotype distribution and haplotype analyze of the HIF2α polymorphisms were performed. Body mass index (BMI), waist circumference, uric acid (UA), high-sensitivity C-reactive protein (hsCRP), lipids, glucose and insulin tolerance - were also measured.

RESULTS

Infertile women with PCOS had a higherBMI and waist circumference, elevated hsCRP and uric acid (UA) levels, impaired glucose tolerance, and increased levels of plasma insulin compared to UI patients and healthy women. SNP analysis of HIF2α revealed that the allele and genotype frequencies of rs4953361 were significantly associated with infertile women with PCOS. Haplotype analysis of the HIF2α polymorphism identified haplotypes TGG and TGA as being associated with infertile women with PCOS. Women with the AA genotype of rs4953361 had a significantly higher BMI and post load plasma glucose and insulin levels than those of women with the GG genotype.

CONCLUSION

Infertile women with PCOS more commonly have metabolic disturbances than those with UI. This is the first study to report an association between HIF2α polymorphisms (rs4953361) and the risk of infertile women with PCOS, not UI, in Han Chinese population. These results require replication in larger populations.In this observational study, we did not report the results of a health care intervention on human participants. The study was approved by the Human Research Ethics Committee of the First Affiliated Hospital of Chongqing Medical University. Clinical data and peripheral blood samples were collected only after explaining the objectives of the study and obtaining a signed informed consent form.

[Overweight or obesity: impact on the results of the first IVF/ICSI attempt]

OBJECTIVES

To evaluate the influence of overweight and obesity on the results of the first in vitro fertilization attempt, without or with intracytoplasmic microinjection (IVF/ICSI), in terms of live births.

METHODS

Retrospective observational study concerning the first IVF/ICSI attempts from 01/01/2006 to 31/12/2017 carried out at the Assisted Reproductive Technology of the CHU of Besançon, studying the delivery rate (excluding frozen embryos transfers), and the data of Assisted Reproductive Technology attempts, in overweight (BMI 25 to 29.9kg/m²) and obese women (BMI≥30kg/m²), compared to women with a standard BMI (18 to 24.9kg/m²).

RESULTS

A total of 3192 patients were included. At the end of their first IVF/ICSI attempt, the delivery rate of women with standard BMI was 34.7%. The delivery rate was significantly lower in overweight women (29.5%, p=0.011) and comparable in obese women (32.4%, p=0.476). The birth rate of women with a BMI≥25 kg/m² was also significantly lower than that of women with a standard BMI (30.4% versus 34.7%, p=0.019). After multivariate analysis, the delivery rate in overweight patients remained significantly lower compared to the population with standard BMI (OR=0.707; 95% CI 0.561-0.890), and comparable in obese patients (OR=0.796; 95% CI 0.585-1.084).

CONCLUSION

The delivery rate was lower in overweight women, whereas it was not significantly different in obese women.

Association between maternal prepregnancy body mass index and pregnancy outcomes following assisted reproductive technology: A systematic review and dose-response meta-analysis

This systematic review investigated dose-response relationship between maternal prepregnancy body mass index (BMI) and pregnancy outcomes following assisted reproductive technology, including clinical pregnancy rate (CPR), miscarriage rate (MR), and live birth rate (LBR). We searched four major databases and finally included 105 studies involving more than 271,632 pregnant women. We performed linear or nonlinear dose-response meta-analyses using random effects models. At per-woman level, pooling of unadjusted estimates shown an inverted J-shaped relationship between maternal BMI and CPR; pooling of adjusted estimates showed a linear association, suggesting statistical association between higher maternal BMI and lower CPR (adjusted OR [aOR] for 5-unit increase in BMI: 0.96, 95%CI: 0.94-0.98). At per-cycle level, linear dose-response relationship was found between maternal BMI and CPR (crude relative risk, RR, [cRR] for 5-unit increase in BMI 0.97, 0.96-0.98; aOR 0.96, 0.94-0.99). Linear dose-response relationship was established between maternal BMI and the outcomes of MR or LBR (higher BMI associated with higher MR [cRR 1.15, 1.08-1.22] and lower LBR [cRR 0.91, 0.88-0.94] at per-woman level). Sensitivity analyses showed no significant changes. In conclusion, there is dose-response relationship between maternal BMI and pregnancy outcomes following assisted reproductive technology. Higher BMI values may suggest suboptimal pregnancy outcomes.

Preconception Evaluation Before In Vitro Fertilization

Importance

Infertility poses a substantial public health problem for women of reproductive age, in the United States and globally. Infertility can be overcome with a variety of emerging assisted reproductive technologies (ARTs). In vitro fertilization (IVF) currently represents the most commonly utilized method of ART and is typically associated with the highest clinical pregnancy rate and live birth rate compared with other infertility treatment options. However, proper preconception evaluation and counseling is paramount for optimizing IVF and pregnancy outcomes.

Objective

This article aims to outline current guidelines and recommendations for comprehensive preconception evaluation before initiation of IVF.

Evidence Acquisition

Articles were obtained from PubMed, ACOG committee opinions 781 and 762, and relevant textbook chapters.

Results

A variety of recommendations and best practices exist for optimally managing patients seeking IVF. Special attention must be paid to the workup of certain patient populations, such as those with age older than 35 years, uterine abnormalities, comorbidities (especially hypertension, diabetes, and thrombophilias), and obesity. In addition, many lifestyle factors must be addressed before IVF initiation, such as smoking, illicit drug use, and inadequate nutrition. Preconception counseling and expectation management is key to optimizing pregnancy outcome.

Conclusion and Relevance

A myriad of patient and environmental factors impact the potential success rates of IVF in treating infertility. Providers must be equipped to provide data-driven, patient-centered counseling before initiation of IVF.

Adverse effects of pre-pregnancy maternal underweight on pregnancy and perinatal outcomes in a freeze-all policy

BACKGROUND

Underweight and overweight may affect reproduction and interfere with treatment of infertility. In the present retrospective analysis, we sought to evaluate the effect of low body mass index (BMI) on pregnancy and perinatal outcomes in frozen-thawed embryo transfer (FET) cycles.

METHODS

This study involved 8755 FET cycles in a single IVF center during the period from January 2009 to December 2018. Both pregnancy and perinatal outcomes were assessed in women who were underweight, normal weight, and overweight as defined based on a respective BMI < 18.5 kg/m², ≥ 18.5 BMI < 24.9 kg/m², and BMI ≥ 25 kg/m².

RESULTS

Being underweight was linked to reduced implantation rates as compared to a normal weight (33.56% vs. 37.26%). Similarly, when comparing outcomes in underweight women to those in normal weight women, rates of clinical pregnancy (48.14% vs. 53.85%) and ongoing pregnancy (43.04% vs. 50.47%) were reduced. Rates of miscarriage were markedly reduced in the normal weight group relative to the overweight group (10.73% vs. 13.37%). Perinatal outcomes were largely comparable for all groups, with the exception of very low birth weight rates (normal weight:0.58% vs. overweight: 2.03%), very small for gestational age rates (normal weight:1.31% vs. overweight:3.55%) and very preterm delivery rates (normal weight:0.82% vs. overweight: 2.03%), which were significantly elevated for overweight mothers.

CONCLUSIONS

These results indicate that being underweight is linked to negative pregnancy outcomes when undergoing FET-based IVF.

Relationships between Follicle-Stimulating Hormone and Adiponectin in Postmenopausal Women

Beyond fertility, follicle-stimulating hormone (FSH) may exert action on adipocytes, which are the major source of adiponectin and leptin, linking to insulin resistance. Therefore, we evaluated the relationships between FSH and adipocyte-derived hormones. This cross-sectional study enrolled postmenopausal women aged 40–65 years. The variables measured in this study included clinical parameters, fasting levels of sex hormones, glucose, insulin, and adipokines. A total of 261 women without breast cancer, 88 women with breast cancer receiving tamoxifen, and 59 women with breast cancer receiving additional gonadotropin-releasing hormone analogs were enrolled in this study. Significant differences in the levels of adiponectin, leptin, and FSH were observed between the non-breast cancer group and the breast cancer groups. Spearman’s rank test revealed significant associations of FSH with either body mass index (BMI) or homeostatic model assessment of insulin resistance (HOMA-IR) values in the non-breast cancer group. After adjusting for BMI, age, and menopause duration, FSH levels were significantly associated with adiponectin (p < 0.001) and the leptin-to-adiponectin ratio (p = 0.008) in the non-breast cancer group, but they were only significantly associated with adiponectin (p = 0.001) in the breast cancer group receiving tamoxifen. Our data show that FSH levels are independently associated with adiponectin levels in postmenopausal women, suggesting that adiponectin may link FSH to metabolic relationships in postmenopausal female.

Impact of Women Obesity and Obesity Severity on Live Birth Rate after In Vitro Fertilization

Access to in vitro fertilization (IVF) for obese women varies across centers, and the impact of obesity on IVF outcomes is widely discussed. We assessed the impact of obesity and its severity on live birth rate (LBR) after IVF. We included women treated for IVF in our center. Data were prospectively collected in the BabySentry^TM software. LBR per cycle and cumulative LBR including all attempts of the couple were calculated, considering transfer of both fresh and frozen embryos. Of 1588 included women (2379 controlled ovarian stimulations), 70.2%, 19.5%, 7.9%, and 2.4% were normal-weight, overweight, class I obesity, and class II/III obesity, respectively. For each cycle, LBR did not differ according to BMI category. Adjusted odds ratios (95% confidence intervals) for obtaining a live birth at the first cycle were 1.11 (0.78–1.58) for overweight, 1.17 (0.70–1.95) for class I obese, and 1.05 (0.48–2.31) for class II/III obese women, as compared with normal-weight women. Similarly, no significant associations were found at cycles 2, 3, and 4. Cumulative LBR increased with the number of cycles, independently of the BMI class (p log-rank = 0.91). After adjustment, obesity status did not impact significantly the miscarriage rate, regardless of the cycle. In conclusion, neither women obesity nor its severity impacted the cumulative LBR after IVF.

Cumulative Live Birth Rates According to Maternal Body Mass Index After First Ovarian Stimulation for in vitro Fertilization: A Single Center Analysis of 14,782 Patients

Objective: To investigate the cumulative live birth rates (CLBR) according to body mass index (BMI) in women undergoing their first in vitro fertilization (IVF). Design: Retrospective cohort analysis. Setting: An IVF clinic in a public hospital. Patients: This is a retrospective study of 14,782 patients undergoing their first fresh IVF cycles and subsequent frozen embryo transfers in our clinic from January 2014 to January 2017. The follow-up for CLBR continued until January 2019. Patients with a BMI <18.5 kg/m2 were considered to be underweight and those with a BMI > 24 kg/m2 were considered to be overweight. Patients with a BMI ≥ 28 kg/m2 were considered to be obese. Intervention(s): None. Primary Outcome Measure: The primary outcome was cumulative live birth rate (CLBR). Result(s): This study illustrated the "inverted U shape" associations between body weight and IVF outcome (CLBR). The turning points in threshold analysis, as found by an automatic search, were BMIs of 18.5 and 30.4 kg/m2. The main finding of this retrospective data analysis is that the CLBR increased in underweight women, plateaued for normal weight and overweight women with a BMI between 18.5 and 30.4 kg/m2, and decreased in obese women. Conclusion(s): The data suggested an "inverted U shape" association between BMI and CLBR. The CLBR increases in underweight women, plateaus in normal weight and overweight women, and then decreases in obese women.

Parameters impacting the live birth rate per transfer after frozen single euploid blastocyst transfer

Background

To assess the predictive value of patient characteristics, controlled ovarian stimulation and embryological parameters on the live birth outcome of single euploid frozen-warmed blastocyst transfer (FBT).

Methods

This was a retrospective cohort study including 707 single FBTs after preimplantation genetic testing for aneuploidy (PGT-A) that were performed from October 1, 2015, to January 1, 2018. The effects of patient-, cycle- and embryology-related parameters on the live birth outcome after FBT were assessed.

Results

In the subgroup analysis based on live birth, patients who achieved a live birth had a significantly lower body mass index (BMI) than patients who did not achieve a live birth (22.7 (21.5–24.6) kg/m² vs 27 (24–29.2) kg/m², p<0.001). The percentage of blastocysts with inner cell mass (ICM) A or B was significantly higher among patients achieving a live birth, at 91.6% vs. 82.6% (p<0.001). Day-5 biopsies were also more prevalent among patients achieving a live birth, at 82.9% vs 68.1% (p<0.001). On the other hand, the mitochondrial DNA (mtDNA) levels were significantly lower among cases with a successful live birth, at 18.7 (15.45–23.68) vs 20.55 (16.43–25.22) (p = 0.001). The logistic regression analysis showed that BMI (p<0.001, OR: 0.789, 95% CI [0.734–0.848]), day of trophectoderm (TE) biopsy (p<0.001, OR: 0.336, 95% CI [0.189–0.598]) and number of previous miscarriages (p = 0.004, OR: 0.733, 95% CI [0.594–0.906]) were significantly correlated with live birth. Patients with elevated BMIs, cycles in which embryos were biopsied on day-6 and a higher number of miscarriages were at increased risks of reduced live birth rates.

Conclusion

A high BMI, an embryo biopsy on day-6 and a high number of miscarriages negatively affect the live birth rate after single euploid FBT.

Insulin Reduces Reaction of Follicular Granulosa Cells to FSH Stimulation in Women With Obesity-Related Infertility During IVF

CONTEXT

Women with obesity usually need larger doses of FSH for ovarian stimulation, resulting in poor outcomes; however, the mechanism is still unclear.

OBJECTIVE

To investigate the molecular regulation of FSH receptor (FSHR) expression associated with obesity.

DESIGN

Case-control study to improve in vitro fertilization (IVF) outcomes.

PATIENTS

Women with obesity (82) and women who were overweight (457) undergoing IVF and 1790 age-matched controls with normal weight from our reproductive medicine center.

MAIN OUTCOME MEASURES

FSHR expression was decreased in parallel with body mass index (BMI), whereas the estradiol (E2) level on the human chorionic gonadotropin (hCG) trigger day was significantly lower.

RESULTS

FSHR expression in human granulosa cells (hGCs), both mRNA (P = 0.02) and protein (P = 0.001) levels, was decreased in women who were overweight or obese. Both insulin (P < 0.001) and glucose (P = 0.0017) levels were positively correlated with BMI in fasting blood and follicle fluids (FFs) but not with FFs leptin level. We treated human granulosa-like tumor cells (KGN) cells with insulin; E2 production was compromised; the level of phosphorylated (p)-protein kinase B (p-Akt2) decreased, whereas p-glycogen synthase kinase 3 (GSK3) increased; and there were similar changes in hGCs from women with obesity. Stimulated hGCs from women with obesity with compound 21 (CP21), an inhibitor of GSK3β, resulted in upregulated β-catenin activation and increased FSHR expression. CP21 also increased the expression of insulin receptor substrate 1 and phosphatidylinositol 3-kinase (PI3K), as well as p-Akt2.

CONCLUSIONS

Women with obesity in IVF were associated with reduced FSHR expression and E2 production caused by a dysfunctional insulin pathway. Decreased FSHR expression in hGCs from women with obesity and insulin-treated KGN cells could be rescued by an inhibitor of GSK3β, which might be a potential target for the improvement of the impaired FSH-stimulation response in women with obesity.

FSH Beyond Fertility

The traditional view of follicle-stimulating hormone (FSH) as a reproductive hormone is changing. It has been shown that FSH receptors (FSHRs) are expressed in various extra-gonadal tissues and mediate the biological effects of FSH at those sites. Molecular, animal, epidemiologic, and clinical data suggest that elevated serum FSH may play a significant role in the evolution of bone loss and obesity, as well as contributing to cardiovascular and cancer risk. This review summarizes recent data on FSH action beyond reproduction.

A systematic review and meta-analysis of lifestyle and body mass index predictors of successful assisted reproductive technologies

OBJECTIVE

Lifestyle (smoking, drinking alcohol) and body mass index (BMI) predictors of successful outcomes in assisted reproductive technology (ART) treatments were examined in this meta-analysis.

METHOD

A bibliographic search was undertaken using six databases. The review was informed by PRISMA/MOOSE guidelines. Meta-analytic data were analysed using random effects models.

RESULTS

We included 77 studies examining effects of BMI, smoking and drinking alcohol. Patients with a BMI< =24.9 were significantly more likely to achieve LB/pregnancy than with BMI> =25 OR = 1.219 (95% CI:1.128-1.319, z = 4.971, p < .001; I² = 53.779%, p = .001). Non-smokers were significantly more likely to achieve a LB or pregnancy than smokers OR = 1.457 (95% CI:1.228-1.727, z = 4.324, p < .001; I² = 51.883; p = .001). Meta-regression revealed the number of embryos transferred significantly moderated the effects of smoking on ART outcomes, and there was a trend indicating primary infertility and high BMI were also significant moderators. The evidence for drinking alcohol was inconclusive due to the small number of studies.

CONCLUSIONS

This meta-analysis confirms that ART treatment success can be predicted with lifestyle factors. Further, non-smokers' relative odds of pregnancy/live birth increase as more embryos were transferred but there was a trend that the odds of pregnancy/live birth decrease with primary infertility and high BMI.

FSH, Bone Mass, Body Fat, and Biological Aging

The Study of Women's Health Across the Nation has taught us that impending ovarian failure during late perimenopause is associated with a sharp rise in serum FSH, which coincides with the most rapid rate of bone loss and the onset of visceral adiposity. At this time in a woman's life, serum estrogen levels are largely unaltered, so the hypothesis that hypoestrogenemia is the sole cause of bone loss and visceral obesity does not offer a full explanation. An alternative explanation, arising from animal models and human data, is that both physiologic aberrations, obesity and osteoporosis, arise at least in part from rising FSH levels. Here, we discuss recent findings on the mechanism through which FSH exerts biological actions on bone and fat and review clinical data that support a role for FSH in causing osteoporosis and obesity. We will also provide a conceptual framework for using a single anti-FSH agent to prevent and treat both osteoporosis and obesity in women across the menopausal transition.

The effect of female body mass index on in vitro fertilization cycle outcomes: a multi-center analysis

PURPOSE

The aim of this study is to examine the impact of female body mass index (BMI) on IVF cycle outcomes.

METHODS

This is a retrospective cohort study including 51,198 women who initiated their first autologous IVF cycle in 13 fertility centers in the USA between 2009 and 2015. The effect of underweight, overweight, and obese BMI on four different IVF cycle outcomes (cycle cancellation, oocyte and embryo counts, and ongoing clinical pregnancy [OCP]) was evaluated in logistic or Poisson regression analyses with confounders adjusted.

RESULTS

Women with an overweight or obese BMI experienced worse outcomes than those with a normal BMI. These differences included (1) greater odds of cycle cancellation (aOR [95%CI] 1.17 [1.08, 1.26] for overweight, 1.28 [1.15, 1.41] for class-I obesity, and 1.50 [1.33, 1.68] for class-II/III obesity, P < .001 for all); (2) fewer oocytes retrieved (aIRR [95%CI] 0.98 [0.98,0.99] for class-I obesity, 0.93 [0.92,0.94] for class-II/III obesity, P < .001 for both); (3) fewer usable embryos (aIRR [95%CI] 0.98 [0.97,0.99] for overweight, 0.97 [0.96,0.99] for class-I obesity, 0.95 [0.93,0.97] for class-II/III obesity, P < .01 for all); and (4) lower odds of OCP (aOR [95%CI] 0.89 [0.83,0.95] for class-I obesity, 0.86 [0.79,0.93] for class-II/III obesity, P < .001 for both). In a subgroup analysis based on primary infertility diagnosis, these trends persisted in those with male or uterine factor and were especially pronounced in women with ovulatory dysfunction or PCOS.

CONCLUSIONS

A BMI above the normal range was an independent negative prognostic factor for multiple outcomes, including cycle cancellation, oocyte and embryo counts, and OCP. These negative outcomes were most profound in women with class-II/III obesity, ovulatory dysfunction, or PCOS.

Effect of preconceptional orlistat treatment on in-vitro fertilization outcome in overweight/obese women: study protocol for a randomized controlled trial

Background

Obese women have fewer oocytes retrieved, an increased cancelation rate, a higher miscarriage rate, and a lower live birth rate after assisted reproductive technology (ART) treatment compared with women with normal weight. Weight loss before ART treatment can significantly improve pregnancy rates and/or live births. An orlistat plus diet intervention could promote weight loss, but there is no evidence from randomized clinical trials evaluating the effect of orlistat preconceptional treatment on pregnancy outcome in overweight and obese women.

Methods/design

We are conducting a multicenter, randomized placebo-controlled, double-blind clinical trial in overweight and obese women aged 20–40 years undergoing in-vitro fertilization and embryo transfer (IVF-ET) with or without intracytoplasmic sperm injection, to evaluate whether orlistat treatment for 1–3 months before IVF-ET can improve the live birth rate. The primary outcome is live birth.

Discussion

The results of this study will provide evidence for the effect of preconceptional orlistat treatment on IVF outcome in overweight/obese women.

Trial registration

Chinese Clinical Trial Registry, ChiCTR-IPR-17011629. Registered on 11 June 2017.

Electronic supplementary material

The online version of this article (10.1186/s13063-018-2780-7) contains supplementary material, which is available to authorized users.

Age-specific reference values and cut-off points for anti-müllerian hormone in infertile women following a long agonist treatment protocol for IVF

PURPOSE

The aims of this study were to determining the reference value of anti-müllerian hormone (AMH) in infertile women and effect of AMH on different ovarian responses in the stratum of BMI categories.

METHODS

Through a retrospective cohort study the information of 816 infertile patients referring to the referral infertility clinic of Mahdiyeh Hospital since the beginning of 2011 until the end of January 2016 were used. The normal-based method was undertaken to calculate age-specific AMH percentiles. To determine the effect of AMH on the outcomes of different ovarian responses following adjustment of associated variables, the multinomial regression model was used.

RESULTS

Estimated reference intervals for AMH corresponding to the 2.5 and 97.5th‰ in patients with normal ovarian response are from 0.096 to 6.2 ng/mL. These values for percentiles of 5, 10, 25, 50, 75, 90, and 95% are, respectively, 0.18, 0.33, 0.77, 1.68, 3.05, 4.45, and 5.36 ng/dL. Also the reference value for the 20-year-old participants has a maximum range (0.12-7.64), while for 43-year-old ones has the lowest range (0.08-5.3). Among participants under and above 35 years old, the optimal cut-off points for predicting normal ovarian response are, respectively, 1.5 and 1.2 ng/dL. With each unit increase in the log of AMH concentration, the odds of having excessive ovarian response in patients with normal weight compared to that of having normal ovarian response is 32% higher.

CONCLUSIONS

Determining AMH reference values in IVF candidates allows specialists to measure only AMH plasma levels in IVF candidates so as to find whether or not the ovarian response is normal before applying other therapeutic measures; accordingly, they can adjust a treatment plan for each individual separately.

Effect of pre-gravid body mass index on outcomes of pregnancies following in vitro fertilization

PURPOSE

To examine the effect of pre-gravid body mass index (BMI) on perinatal outcomes in in vitro fertilization (IVF) singleton pregnancies.

METHODS

Retrospective population-based cohort study. All singleton pregnancies delivered at ≥ 22 weeks' in Slovenia between 2002 and 2015 were included. Logistic regression analysis was used to examine the relationship between BMI category and outcomes, controlling for potential confounding variables. Interaction term was included to evaluate whether effects of obesity on perinatal outcomes differ in IVF vs. non-IVF pregnancies. We counted the frequencies of hypertensive disorders of pregnancy, gestational diabetes, cesarean delivery, preterm births, and small as well as large for gestational age neonates, neonatal respiratory distress syndrome, neonatal intraventricular hemorrhage, and perinatal deaths.

RESULTS

Pre-gravid overweight and obesity were associated with higher rates of hypertensive disorders, gestational diabetes, and cesarean deliveries in both IVF and non-IVF pregnancies. Pre-gravid underweight was associated with small for gestational age neonates in IVF and non-IVF pregnancies. There was a significantly lower effect of pre-gravid obesity on the incidence of hypertensive disorders (odds ratio (OR) 0.7; 95% confidence interval (CI) 0.5-0.9) and cesarean delivery (OR 0.8; 95% CI 0.7-0.99) in IVF vs. non-IVF pregnancies. The effect of pre-gravid obesity on neonatal mortality was significantly greater in IVF compared to non-IVF pregnancies (OR 4.6; 95% CI 1.4-15.8).

CONCLUSIONS

Pre-gravid BMI has an important effect on perinatal outcomes in pregnancies following IVF.

The role of female obesity on in vitro fertilization outcomes

The aim of this review is to analyze the role of obesity on fertility outcome in women undergoing in vitro fertilization (IVF) with respect to clinical or live birth rates and pregnancy loss rates. Despite findings from several earlier and newer studies that obesity does not adversely affect pregnancy outcome in women attempting conception, numerous reports from mostly recent studies suggest that obesity undoubtedly impairs IVF outcomes. Obesity impairs ovarian responsiveness to gonadotrophin stimulation, requiring higher doses of medication, increased risk of cycle cancelation, pre-term delivery, low birth weight or miscarriage, and decreases implantation, clinical pregnancy or live birth rates compared to women of normal weight. The mechanisms underlying the adverse effects of female obesity on IVF outcome may be primarily explained by functional alterations to the hypothalamic-pituitary-ovarian axis. Additionally, obesity appears to affect deleteriously the number and quality of oocytes or embryos, and impairs endometrial decidualization which is necessary for uterine receptivity. Nevertheless, attaining normal body weight by the use of lifestyle modifications, including a healthy diet and exercise over time of several months before and during an IVF treatment, may be successful in achievement of gradual and sustainable weight loss with improvement of IVF outcome.

The correlation between raised body mass index and assisted reproductive treatment outcomes: a systematic review and meta-analysis of the evidence

Background

Public funding for fertility services within the United Kingdom is limited, and therefore, strict guidance exists regarding who can be offered treatment under the National Health Service (NHS). Body mass index (BMI) is a universal criteria adopted by both the public and private sector.

This study addresses an important aspect of the impact of a raised BMI on fertility treatment outcomes. We standardise the analysis of the data by only including studies incorporating the WHO BMI criteria; the current reference point for clinicians and clinical commissioning groups in ascertaining which group of patients should receive treatment. This study is an update of the previous systematic review performed in 2010, with the inclusion of a larger number of cycles from central databases such as the Society for Assisted Reproductive Technology (SART).

Methods

An electronic literature search was conducted through the Cochrane, Medline and Embase libraries. Data extraction for each outcome measure was pooled and expressed as an odds ratio with 95% confidence intervals. Where clinical heterogeneity was evident, the random effects model was used to calculate the risk ratio and a fixed effects model was used for the remaining studies. A p value < 0.05 was considered statistically significant.

Results

A total of 49 studies have been identified and included in this systematic review. Overweight and obese (BMI ≥ 25 kg/m²) women have a statistically significant lower live birth rate (OR 0.81, 95% CI 0.74–0.89, p < 0.00001) following Assisted Reproductive Technology (ART) when comparisons are drawn to women with a normal BMI. An increase is also demonstrated in the number of miscarriages experienced by women with a BMI ≥ 30 kg/m² (OR 1.52, 95% CI 1.28–1.81, p < 0.00001).

Conclusion

Although this review concludes that a clear impact of BMI on ART outcomes is demonstrated, there remains questions as to the pathophysiology underlying these differences. This review supports the government’s stringent criteria regarding BMI categories under which NHS funding is made available for ART, through a clear description of poor reproductive outcomes in women with a BMI ≥ 30 kg/m².

Effect of Frozen Embryo Transfer and Progestin-primed Ovary Stimulation on IVF outcomes in women with high body mass index

Among women undergoing IVF, high BMI negatively affects pregnancy outcomes when using the conventional ovary stimulating protocols combined with fresh embryo transfer. Therefore, finding a proper treatment for these high BMI women is more important and urgent when obesity is prevalent. In our study, we reported a retrospective study of 4457 women who were divided into normal BMI group (18.5 kg/m²–24.9 kg/m²) and high BMI group (≥25 kg/m²) undergoing 4611 IVF treatment cycles with frozen embryo transfer (FET). We found the high BMI group originally had the poor oocytes performance, but after FET they got the similar pregnancy outcomes as the normal BMI group. Then under FET we analyzed the IVF outcomes of our new progestin-primed ovary stimulation (PPOS) protocol, indicating that the hMG + MPA (4 or 10 mg/d) groups had the obvious better pregnancy results than the conventional short group in the high BMI group, and binary logistic regression analysis showed the hMG + MPA (10 mg/d) group was associated with better pregnancy outcomes than the hMG + MPA (4 mg/d) group. These results indicate PPOS - hMG + MPA (10 mg/d) combined with FET might be a new potential treatment choice for the high BMI women undergoing IVF treatments.

Extremities of body mass index and their association with pregnancy outcomes in women undergoing in vitro fertilization in the United States

OBJECTIVE

To investigate the associations among underweight body mass index (BMI), pregnancy, and obstetric outcomes among women using assisted reproductive technology (ART).

DESIGN

Retrospective cohort study using national data and log binomial regression.

SETTING

Not applicable.

PATIENT(S)

Women undergoing IVF in the United States from 2008 to 2013.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Pregnancy outcomes (intrauterine pregnancy, live birth rates) per transfer, miscarriage rate per pregnancy, and low birth weight and preterm delivery rates among singleton and twin pregnancies.

RESULT(S)

For all fresh autologous in vitro fertilization (IVF) cycles in the United States from 2008 to 2013 (n = 494,097 cycles, n = 402,742 transfers, n = 180,855 pregnancies) reported to the national ART Surveillance System, compared with normal weight women, underweight women had a statistically significant decreased chance of intrauterine pregnancy (adjusted risk ratio [aRR] 0.97; 95% confidence interval [CI], 0.96-0.99) and live birth (aRR 0.95; 95% CI, 0.93-0.98) per transfer. Obese women also had a statistically decreased likelihood of both (aRR 0.94; 95% CI, 0.94-0.95; aRR 0.87; 95% CI, 0.86-0.88, respectively). Among cycles resulting in singleton pregnancy, both underweight and obese statuses were associated with increased risk of low birth weight (aRR 1.39; 95% CI, 1.25-1.54, aRR 1.26; 95% CI, 1.20-1.33, respectively) and preterm delivery (aRR 1.12; 95% CI, 1.01-1.23, aRR 1.42; 95% CI, 1.36-1.48, respectively). The association between underweight status and miscarriage was not statistically significant (aRR 1.04; 95% CI, 0.98-1.11). In contrast, obesity was associated with a statistically significantly increased miscarriage risk (aRR 1.23; 95% CI, 1.20-1.26).

CONCLUSION(S)

Among women undergoing IVF, prepregnancy BMI affects pregnancy and obstetric outcomes. Underweight status may have a limited impact on pregnancy and live-birth rates, but it is associated with increased preterm and low-birth-weight delivery risk. Obesity negatively impacts all ART and obstetric outcomes investigated.

Effect of body mass index on the outcomes of controlled ovarian hyperstimulation in Chinese women with polycystic ovary syndrome: a multicenter, prospective, observational study

PURPOSE

The purpose of the present study is to explore the influence of body mass index (BMI) on outcomes of in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI) techniques in Chinese women with polycystic ovary syndrome (PCOS).

METHODS

This was a multicenter, prospective, observational study that enrolled 800 subjects with PCOS from nine hospitals in China. Patients were categorized according to BMI categories: underweight, <18.5 kg/m²; normal, 19-23.9 kg/m²; overweight, 24-27.9 kg/m²; and obese, ≥28 kg/m². Total recombinant follicle-stimulating hormone (rFSH) dose used, estradiol, and progesterone levels on human chorionic gonadotropin (hCG) day; implantation rate; and biochemical, clinical, and ongoing pregnancy rates were compared among BMI categories. Hormone levels (estradiol, follicle-stimulating hormone (FSH), LH, testosterone, and progesterone) were measured using electrochemiluminescence assays.

RESULTS

Among the 774 subjects, 27.3 % were overweight and 8.1 % were obese. The rFSH dose used differed significantly among BMI categories (P < 0.001). The implantation rate was lower in obese subjects than that in normal-weight subjects (25.3 vs 45.7 %). Clinical pregnancy rate per transfer differed among BMI categories (P = 0.033), but there was no difference for biochemical (P = 0.327) and ongoing (P = 0.084) pregnancy rates. The miscarriage rate was similar among BMI categories.

CONCLUSIONS

More than one third of Chinese women with PCOS undergoing IVF/ICSI are overweight or obese. Elevated BMI is associated with reduced clinical pregnancy rate but similar ongoing pregnancy rates, suggesting that BMI has little impact on IVF outcomes.

A Comprehensive Analysis of Body Mass Index Effect on in Vitro Fertilization Outcomes

The effect of a raised body mass index (BMI) on the outcome of assisted reproduction technology (ART) still represents a controversial issue. Even less clear is whether BMI acts with a potential detrimental effect on IVF outcomes via a deleterious effect on innate quality of oocytes or on the environmental milieu within the uterus. With the aim to better understand the mechanisms underlying the potential deleterious effect of an increased BMI on IVF outcomes, we have evaluated the effects of female BMI on number and quality of retrieved oocytes, fertilization rate, embryo score and incidences of ongoing pregnancy and live births among couples undergoing IVF in an Italian population. Data from 1602 women who underwent their first IVF cycle were retrospectively analyzed. A significantly reduced percentage of mature oocytes when comparing obese (BMI ≥ 30 kg/m²) and normal-weight patients (BMI = 18.50–24.99 kg/m²) was found. After adjusting for maternal age and other confounders, odds for ongoing pregnancy rate showed no differences across different BMI categories. However, a significant increased odds ratio (OR) could be observed for miscarriage rate in patients with BMI ≥ 25 (OR = 2.5; p = 0.04). These results should be taken into account in order to define optimal strategies for overweight and obese patients referring to ART procedures.

When two obese parents are worse than one! Impacts on embryo and fetal development

The prevalence of overweight and obesity in reproductive-age adults is increasing worldwide. While the effects of either paternal or maternal obesity on gamete health and subsequent fertility and pregnancy have been reported independently, the combination of having both parents overweight/obese on fecundity and offspring health has received minimal attention. Using a 2 × 2 study design in rodents we established the relative contributions of paternal and maternal obesity on fetal and embryo development and whether combined paternal and maternal obesity had an additive effect. Here, we show that parental obesity reduces fetal and placental weights without altering pregnancy establishment and is not dependent on an in utero exposure to a high-fat diet. Interestingly combined parental obesity seemed to accumulate both the negative influences of paternal and maternal obesity had alone on embryo and fetal health rather than an amplification, manifested as reduced embryo developmental competency, reduced blastocyst cell numbers, impaired mitochondrial function, and alterations to active and repressive embryonic chromatin marks, resulting in aberrant placental gene expression and reduced fetal liver mtDNA copy numbers. Further understanding both the maternal cytoplasmic and paternal genetic interactions during this early developmental time frame will be vital for understanding how developmental programming is regulated and for the proposition of interventions to mitigate their effects.