Effects of polycystic ovarian syndrome on in vitro fertilization–embryo transfer outcomes are influenced by body mass index

Impact of body mass index on assisted reproductive technology outcomes in patients with polycystic ovary syndrome: a meta-analysis

The effect of obesity on pregnancy outcomes of patients with polycystic ovary syndrome (PCOS) undergoing assisted reproductive technology (ART) remains unclear. As such, a meta-analysis of recent studies was conducted to probe the effect of being overweight or obese on ART pregnancy outcomes in patients with PCOS. PubMed, Embase, MEDLINE, Scopus and Web of Science were searched from inception to 22 July 2023 without language restrictions. The main indicators were: live birth rate, clinical pregnancy rate, spontaneous abortion rate and multiple pregnancy rate. Ten studies were analysed, with a combined sample size of 247,845. Among patients with PCOS undergoing ART who were overweight or obese, the live birth rate, clinical pregnancy rate, implantation rate and number of retrieved oocytes were lower than in normal-weight patients with PCOS, and the spontaneous abortion rate was higher than in normal-weight patients with PCOS. Obese patients with PCOS undergoing ART had a lower multiple pregnancy rate and a lower number of mature oocytes compared with normal-weight patients with PCOS. The data showed that, among patients with PCOS, being overweight or obese has a negative effect on ART pregnancy outcomes. This meta-analysis may inform guidelines for pregnancy with ART, and encourage overweight or obese patients with PCOS to lose weight.

The details matter: personalized prediction of live birth after in vitro fertilization in women with polycystic ovary syndrome

OBJECTIVE

To derive and internally validate a clinical prediction model for live birth (LB) in women with polycystic ovary syndrome (PCOS) undergoing in vitro fertilization (IVF).

DESIGN

Retrospective cohort study.

SETTING

Four academic reproductive endocrinology clinics.

PATIENTS

A total of 207 women with PCOS confirmed using Rotterdam criteria undergoing their first fresh IVF cycle.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURE

The primary outcome was cumulative LB per IVF cycle start. This included any LB that resulted from either fresh embryo transfer or any subsequent frozen embryo transfer from embryos obtained at the index oocyte retrieval. A prediction model was derived using multivariable logistic regression. Covariates considered for inclusion in the prediction model included demographic characteristics, medical history, and prior fertility treatment. Predicted probabilities for LB were calculated using the prediction model which included the 90% shrinkage factor for each adjusted odds ratio.

RESULTS

The final model, on the basis of maximization of the area under the receiver operating characteristic curve, included age < 35 years, White race, presence of polycystic ovaries on ultrasound (polycystic ovary morphology), normal body mass index (<25 kg/m2), being metabolically healthy (no metabolic risk factors), and being a nonresponder to ovulation induction agents including letrozole and clomiphene citrate. The area under the receiver operating characteristic curve score for the model was 0.68 (95% confidence interval [CI]: 0.60, 0.77). Predicted probabilities of LB ranged from 8.1% (95% CI: 2.8, 21.5) for a woman who had no favorable predictors to 74.2% (95% CI: 59.5, 84.9) for a woman who had all favorable predictors.

CONCLUSION

Our study demonstrated that, in addition to anovulation, the underlying pathophysiology and associated comorbidities alter the likelihood of a successful pregnancy in women with PCOS undergoing IVF. Further validation of this model is needed before it can serve as a tool to personalize prediction estimates for the probability of LB in women with PCOS.

Live birth rate per fresh embryo transfer and cumulative live birth rate in patients with PCOS under the POSEIDON classification: a retrospective study

Background

Ovarian stimulation (OS) for in vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI) in women with PCOS often results in multiple follicular development, yet some individuals experience poor or suboptimal responses. Limited data exist regarding the impact of poor/suboptimal ovarian response on pregnancy outcomes in women with PCOS.

Objectives

The aim of this study was to evaluate whether the live birth rate (LBR) per fresh embryo transfer and cumulative live birth rate (CLBR) per aspiration cycle differ in women with PCOS defined by the Patient-Oriented Strategy Encompassing IndividualizeD Oocyte Number (POSEIDON) criteria.

Methods

A retrospective study involving 2,377 women with PCOS who underwent their first IVF/ICSI cycle at Sun Yat-sen Memorial Hospital from January 2011 to December 2020 was used. Patients were categorized into four groups based on age, antral follicle count, and the number of oocytes retrieved, according to the POSEIDON criteria. The LBR and CLBR were compared among these groups. Logistic regression analysis was performed to assess whether the POSEIDON criteria served as independent risk factors and identify factors associated with POSEIDON.

Results

For patients <35 years old, there was no significant difference in the clinical pregnancy rate between POSEIDON and non-POSEIDON patients, whereas POSEIDON patients exhibited lower rates of implantation and live birth. POSEIDON Group 1a displayed lower rates of implantation, clinical pregnancy, and live birth. However, no significant differences were observed in the rates of clinical pregnancy and live birth between POSEIDON Group 1b and non-POSEIDON groups. For patients ≥35 years old, there were no significant differences in the rates of implantation, clinical pregnancy, and live birth between POSEIDON and non-POSEIDON patients. CLBRs were significantly lower in POSEIDON Groups 1 and 2, compared with the non-POSEIDON groups. The levels of body mass index (BMI), follicle-stimulating hormone (FSH), and antral follicle count (AFC) were associated with POSEIDON hypo-response. POSEIDON was found to be associated with lower CLBR, but not LBR per fresh embryo transfer.

Conclusions

In patients with PCOS, an unexpected suboptimal response can achieve a fair LBR per fresh embryo transfer. However, CLBR per aspirated cycle in POSEIDON patients was lower than that of normal responders. BMI, basal FSH level, and AFC were independent factors associated with POSEIDON. Our study provides data for decision-making in women with PCOS after an unexpected poor/suboptimal response to OS.

Overweight and obesity determined by body mass index criteria for Asian populations adversely affect assisted reproductive outcomes among Chinese women with polycystic ovary syndrome

BACKGROUND

Obesity is a common feature in women with polycystic ovary syndrome (PCOS) and is associated with multiple adverse reproductive outcomes. However, the impact of overweight and obesity on reproductive outcomes of women with PCOS who underwent in vitro fertilization-embryo transfer (IVF-ET) is currently controversial and appropriate body mass index (BMI) levels differ across ethnic groups.

METHODS

This was a retrospective study including 1066 women with PCOS receiving IVF treatment at our institution between January 2018 and June 2021, among whom 960 underwent their first fresh or frozen embryo transfer. Participants were categorized according to BMI cut-off values proposed by the World Health Organization for Asian populations: normal weight (BMI < 23 kg/m2), overweight (BMI: 23-24.9 kg/m2), and obesity (BMI ≥ 25 kg/m2). The effect of BMI on clinical and embryological outcomes was evaluated by descriptive statistics and logistic regression models with confounders adjusted. The dose-response relationship between BMI as a continuous variable and IVF outcomes is also explored.

INTERVENTIONS

no RESULTS: Increasing BMI was associated with significantly lower numbers of total oocytes retrieved, metaphase II oocytes, two pronuclear (2PN) zygotes, and good-quality embryos among women with PCOS. Patients with PCOS with a BMI ≥ 23 kg/m2 had significantly lower live birth rates (41.9% vs. 49.1%; adjusted odds ratio [aOR], 0.75; 95% confidence interval [CI], 0.57-0.97) and implantation rates (35.8% vs. 43.9%; aOR, 0.76; 95% CI, 0.61-0.93) than those with normal BMI. Moreover, BMI showed a non-linear relationship (p for nonlinearity <0.001) with the number of 2PN zygotes with the curve becoming steeper as BMI surpassed 22.4 kg/m2.

CONCLUSIONS

Patients with PCOS with a BMI ≥ 23 kg/m2 have lower live birth rates than those with a BMI < 23 kg/m2. Defining obesity and overweight with ethnicity-specific BMI cut-offs may help to improve IVF outcomes among PCOS patients.

Adiposity and lipid metabolism indicators mediate the adverse effect of glucose metabolism indicators on oogenesis and embryogenesis in PCOS women undergoing IVF/ICSI cycles

BACKGROUND

Polycystic ovary syndrome (PCOS) women have high incidences of dyslipidemia, obesity, impaired glucose tolerance (IGT), diabetes, and insulin resistance (IR) and are fragile to female infertility. Obesity and dyslipidemia may be the intermediate biological mechanism for the associations between glucose metabolism dysfunction and abnormal oogenesis and embryogenesis.

METHODS

This retrospective cohort study was performed at a university-affiliated reproductive center. A total of 917 PCOS women aged between 20 and 45 undergoing their first IVF/ICSI embryo transfer cycles from January 2018 to December 2020 were involved. Associations between glucose metabolism indicators, adiposity and lipid metabolism indicators, and IVF/ICSI outcomes were explored using multivariable generalized linear models. Mediation analyses were further performed to examine the potential mediation role of adiposity and lipid metabolism indicators.

RESULTS

Significant dose-dependent relationships were found between glucose metabolism indicators and IVF/ICSI early reproductive outcomes and between glucose metabolism indicators and adiposity and lipid metabolism indicators (all P < 0.05). Also, we found significant dose-dependent relationships between adiposity and lipid metabolism indicators and IVF/ICSI early reproductive outcomes (all P < 0.05). The mediation analysis indicated that elevated FPG, 2hPG, FPI, 2hPI, HbA1c, and HOMA2-IR were significantly associated with decreased retrieved oocyte count, MII oocyte count, normally fertilized zygote count, normally cleaved embryo count, high-quality embryo count, or blastocyst formation count after controlling for adiposity and lipid metabolism indicators. Serum TG mediated 6.0-31.0% of the associations; serum TC mediated 6.1-10.8% of the associations; serum HDL-C mediated 9.4-43.6% of the associations; serum LDL-C mediated 4.2-18.2% of the associations; and BMI mediated 26.7-97.7% of the associations.

CONCLUSIONS

Adiposity and lipid metabolism indicators (i.e., serum TG, serum TC, serum HDL-C, serum LDL-C, and BMI) are significant mediators of the effect of glucose metabolism indicators on IVF/ICSI early reproductive outcomes in PCOS women, indicating the importance of preconception glucose and lipid management and the dynamic equilibrium of glucose and lipid metabolism in PCOS women.

Association between Pre-Pregnancy Overweightness/Obesity and Pregnancy Outcomes in Women with Polycystic Ovary Syndrome: A Systematic Review and Meta-Analysis

Polycystic ovary syndrome (PCOS) is a common metabolic problem in women of reproductive age. Evidence suggests pregnant women with PCOS may have a higher risk of the development of adverse pregnancy outcomes; however, the relationship between pre-pregnancy overweight/obesity and pregnancy outcomes in women with PCOS remains uncertain. We try to clarify the relationship between pre-pregnancy overweight/obesity and subsequent pregnancy outcomes. Therefore, we conducted this systematic review and meta-analysis. We used the databases obtained from the PubMed, Embase, Web of Science, and Cochrane databases, plus hand-searching, to examine the association between pre-pregnancy overweightness/obesity and pregnancy outcomes in women with PCOS from inception to 4 February 2022. A total of 16 cohort studies, including 14 retrospective cohort studies (n = 10,496) and another two prospective cohort studies (n = 818), contributed to a total of 11,314 women for analysis. The meta-analysis showed significantly increased odds of miscarriage rate in PCOS women whose pre-pregnancy body mass index (BMI) is above overweight (OR 1.71 [95% CI 1.38–2.11]) or obese (OR 2.00 [95% CI 1.38–2.90]) under a random effect model. The tests for subgroup difference indicated the increased risk was consistent, regardless which body mass index cut-off for overweight (24 or 25 kg/m²) or obesity (28 and 30 kg/m²) was used. With the same strategies, we found that pregnant women in the control group significantly increased live birth rate compared with those pregnant women with PCOS as well as pre-pregnancy overweight/obesity (OR 0.79 [95% CI 0.71–0.89], OR 0.78 [95% CI 0.67–0.91]). By contrast, we did not find any association between PCOS women with pre-pregnancy overweight/obesity and preterm birth. Based on the aforementioned findings, the main critical factor contributing to a worse pregnancy outcome may be an early fetal loss in these PCOS women with pre-pregnancy overweight/obesity. Since PCOS women with pre-pregnancy overweightness/obesity were associated with worse pregnancy outcomes, we supposed that weight reduction before attempting pregnancy in the PCOS women with pre-pregnancy overweightness/obesity may improve the subsequent pregnancy outcomes.

Pathology of hyperandrogenemia in the oocyte of polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is the most common ovulatory disorder in the world and is associated with multiple adverse outcomes. The phenotype is widely varied, with several pathologies contributing to the spectrum of the disease including insulin resistance, obesity and hyperandrogenemia. Of these, the role of hyperandrogenemia and the mechanism by which it causes dysfunction remains poorly understood. Early studies have shown that androgens may affect the metabolic pathways of a cell, and this may pose hazards at the level of the mitochondria. As mitochondria are strictly maternally inherited, this would provide an exciting explanation not only to the pathophysiology of PCOS as a disease, but also to the inheritance pattern. This review seeks to summarize what is known about PCOS and associated adverse outcomes with focus on the role of hyperandrogenemia and specific emphasis on the oocyte.

Poor Ovarian Response to Gonadotrophins in PCOS Women after Laparoscopic Ovarian Drilling

Background and Objectives: Polycystic ovary syndrome (PCOS) is a major cause of anovulatory infertility, and ovulation induction is the first-line treatment. If this fails, laparoscopic ovarian drilling (LOD) is used to induce mono-ovulations. There have been implications, that LOD can cause destruction of ovarian tissue and therefore premature ovarian failure. Furthermore, unexpected poor ovarian response (POR) to gonadotrophins can occur in PCOS women after LOD. There have been reports about FSH receptor polymorphisms found in women with PCOS that are related to higher serum FSH levels and POR to gonadotrophins. Materials and Methods: In the present study, we retrospectively analyzed data of 144 infertile PCOS women that had LOD performed before IVF. Results: Thirty of included patients (20.8%) had POR (≤3 oocytes) to ovarian stimulation with gonadotrophins. Women with POR had significantly higher median levels of basal serum FSH (7.2 (interquartile range (IQR), 6.0–9.2) compared to women with normal ovarian response (6.0 (IQR, 5.0–7.4); p = 0.006). Furthermore, women with POR used a significantly higher median cumulative dose of gonadotrophins (1875 IU (IQR, 1312.5–2400) for ovarian stimulation compared to women with normal ovarian response (1600 IU (IQR, 1200–1800); p = 0.018). Conclusion: Infertile PCOS women who experience POR after LOD have significantly higher serum FSH levels compared to women with normal ovarian response after LOD. As these levels are still within the normal range, we speculate that LOD is not the cause of POR. We presume that women with PCOS and POR after LOD could have FSH-R genotypes associated with POR and higher serum FSH levels.

Lipid Metabolism Was Associated With Oocyte in vitro Maturation in Women With Polycystic Ovarian Syndrome Undergoing Unstimulated Natural Cycle

Objective

Hyperlipidemia are common polycystic ovarian syndrome (PCOS)-related metabolic dysfunctions and can adversely affect assisted reproductive technology (ART) outcomes in controlled ovarian hyperstimulation (COH) cycles. The objective of this study is to analyze the relationship between lipid metabolism and ART outcomes in unstimulated natural cycles without the utilization of ovarian induction drugs, which is still uncertain.

Methods

This retrospective study included infertile women with PCOS between 21 and 40 years old undergoing unstimulated natural cycles from January 01, 2006 to December 31, 2019. Lipid metabolism was measured by body mass index (BMI) and serum biochemical parameters including total cholesterol (TC), triglycerides (TG), high and low density lipoprotein cholesterol (HDL-C and LDL-C). ART outcomes were measured by number of oocytes retrieved, oocyte maturation quality and developmental potential, clinical pregnancy and live birth.

Results

A total of 586 patients were included in this study. Multivariate Poisson log-linear analysis showed that high TC (≥5.18 mmol/L), triglycerides (TG) (≥1.76 mmol/L), LDL-C (≥3.37 mmol/L) levelsand low HDL-C levels (≤1.04 mmol/L) were significantly (P_TC = 0.001, P_TG < 0.001, P_HDL–C < 0.001, P_LDL–C < 0.001) associated with increased number of oocytes retrieved. BMI was significantly negatively associated with maturation rate (P < 0.001), fertilization rate (P < 0.001) and transferrable embryo rate (P = 0.002). High TG levels and low HDL-C levels were also associated with decreased maturation rate (P_TG < 0.001, P_HDL–C = 0.026). Logistic regression analysis showed statistically significant association between obesity (≥28.0 kg/m²) and decreased live birth rate (P = 0.004) as well as cumulative live birth rate (P = 0.007).

Conclusion

This is the first study that focused on the relationship between basal lipid metabolism and ART outcomes in women with PCOS undergoing unstimulated natural cycles. The results showed that high levels of lipid metabolic parameters were associated with increased number of oocytes retrieved and obesity was closely associated with impaired oocyte maturation quality and developmental potential as well as poor live birth outcomes.

Impact of body mass index on intracytoplasmic sperm injection in women with polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is a condition that affects fertility. There are two types of PCOS; the normal/lean type and overweight/obese type. The aim of this study was to assess baseline characteristics, ovarian response, quality of oocytes, embryos, pregnancy, implantation and live birth rates in normal/lean and overweight/obese patients with PCOS undergoing ICSI compared with patients without PCOS. This retrospective case-control analytical study included 38 normal/lean and 17 overweight/obese patients with PCOS, and 98 normal/lean and 17 overweight/obese patients without PCOS. Parameters were observed based on baseline characteristics, ovarian response to dosage and duration of gonadotropin administered, number of oocytes, matured oocytes, fertilization rate, embryo quality and development, pregnancy, implantation and live birth rates. Basal serum luteinizing hormone in normal/lean PCOS was significantly higher compared with non-PCOS groups. Total dosage of gonadotropin used was significantly lower in normal/lean PCOS compared with other groups. End estradiol levels in normal/lean PCOS was significantly higher compared with the non-PCOS groups. Number of follicles, retrieved oocytes and matured oocytes were significantly higher in PCOS groups compared with the non-PCOS groups. However, there were no differences in fertilized oocytes, cleavage, number of top-quality embryos, pregnancy, implantation, and live birth rates among groups. This present study suggests that normal/lean PCOS requires lower gonadotropin dosages and that patients with PCOS have more follicles and oocytes compared with patients without PCOS, however the number of fertilized oocytes and embryos from patients with PCOS were the same as those from patients without PCOS and suggested that the quality of retrieved oocytes in PCOS might be compromised.

Early and late pregnancy loss in women with polycystic ovary syndrome undergoing IVF/ICSI treatment: a retrospective cohort analysis of 21 820 pregnancies

OBJECTIVE

To examine early and late pregnancy loss in women with and without polycystic ovary syndrome (PCOS) undergoing IVF/ICSI transfers.

DESIGN

Retrospective cohort study.

SETTING

Reproductive medicine centre at a tertiary hospital.

POPULATION

We studied women with a positive β-human chorionic gonadotropin (β-hCG) after in vitro fertilisation/intra-cytoplasmic sperm injection (IVF/ICSI) treatment from May 2014 to April 2019.

METHODS

Odds ratios (OR) for early (≤13 weeks) and late (>13 weeks) pregnancy loss were calculated among women with and without PCOS for plurality of the pregnancy with adjustment for confounding factors.

MAIN OUTCOME MEASURES

Early pregnancy loss (EPL) and late pregnancy loss (LPL).

RESULTS

From 21 820 women identified with a positive β-hCG, 2357 (10.8%) women had PCOS, and 19 463 (89.2%) women did not. EPL occurred in 16.6% (391) of women with PCOS versus 18.3% (3565) in women with non-PCOS (OR 0.89, 95% CI 0.79-0.99, P = 0.04). After adjustment for age and other confounders, the rate of EPL was not statistically significantly associated with PCOS status (adjusted OR [aOR] 0.91, 95% CI 0.80-1.05). Women with PCOS demonstrated a higher rate of LPL (6.4% in PCOS versus 3.6% in non-PCOS, OR 1.81, 95% CI 1.48-2.21, P < 0.001). In multivariable analysis, the potential impact of PCOS was less strong (aOR 1.38, 95% CI 0.96-1.98), with BMI and maternal comorbidities also associated with LPL (aOR 1.08, 95% CI 1.04-1.1 and aOR 2.07, 95% CI 1.43-3.00, respectively).

CONCLUSIONS

Polycystic ovary syndrome was not independently associated with EPL. There was an increased risk of LPL but this difference was not statistically significant.

TWEETABLE ABSTRACT

Polycystic ovary syndrome women are at increased risk of late pregnancy loss, partly driven by elevated BMI and maternal comorbidities.

The insulin signaling pathway is dysregulated in cumulus cells from obese, infertile women with polycystic ovarian syndrome with an absence of clinical insulin resistance

Methods:

This is a cohort study, conducted at a university-based reproductive medicine center and private reproductive medicine center that aimed to evaluate granulosa cumulus cell gene expression in the insulin signaling pathway in Polycystic Ovary Syndrome (PCOS) patients undergoing in vitro fertilization (IVF) treatment and to compare the cumulus gene expression between normal weight and obese women without clinical insulin resistance. Fifteen PCOS patients, nine normal weight patients and six obese patients presenting normal HOMA IR (Homeostasis Model Assessment–Insulin Resistance), participated. Patients underwent oocyte retrieval for IVF and after the procedure, granulosa cumulus cells were removed from the oocytes for RNA extraction. Quantitative polymerase chain reaction (PCR) array analysis of 84 genes from insulin signaling pathway was conducted. The results were expressed as fold up- or fold down-expression in obese patients compared with normal weight patients. Any fold change ⩾3 or ⩽3 and any p ⩽ 0.05 were considered statistically significant.

Results:

There were 10 genes that were overexpressed in obese compared with normal weight women, BCL2L1, BRAF, CBL, DOK1, FBP1, FRS2, MTOR, PCK2, RPS6KA1, and SORBS1, that had a fold change ⩾3 and p ⩽ 0.05.

Discussion:

In the obese group, the overexpressed genes are mainly responsible for the proliferation and differentiation of cumulus cells during oocyte maturation, insulin resistance, apoptosis regulation, and glucose metabolism during early embryogenesis, suggesting that in the follicular environment, insulin resistance is present even in the absence of clinical signs.

Conclusion:

Together, our findings and the related literature suggest that those alterations may be associated with the worse prognosis of follicular development and oocyte maturation observed in PCOS obese women.

Prenatal androgen induced lean PCOS impairs mitochondria and mRNA profiles in oocytes

Polycystic ovary syndrome (PCOS) is the most common ovulatory defect in women. Although most PCOS patients are obese, a subset of PCOS women are lean but show similar risks for adverse fertility outcomes. A lean PCOS mouse model was created using prenatal androgen administration. This developmentally programmed mouse model was used for this study. Our objective was to investigate if mitochondrial structure and functions were compromised in oocytes obtained from lean PCOS mouse. The lean PCOS mouse model was validated by performing glucose tolerance test, HbA1c levels, body weight and estrous cycle analyses. Oocytes were isolated and were used to investigate inner mitochondrial membrane potential, oxidative stress, lipid peroxidation, ATP production, mtDNA copy number, transcript abundance, histology and electron microscopy. Our results demonstrate that lean PCOS mice has similar weight to that of the controls but exhibited glucose intolerance and hyperinsulinemia along with dysregulated estrus cycle. Analysis of their oocytes show impaired inner mitochondrial membrane function, elevated reactive oxygen species (ROS), increased RNA transcript abundance and aberrant ovarian histology. Electron microscopy of the oocytes showed impaired mitochondrial ultrastructure. In conclusion, the lean PCOS mouse model shows a decreased oocyte quality related to impaired mitochondrial ultrastructure and function.

Female obesity is negatively associated with live birth rate following IVF: a systematic review and meta-analysis

BACKGROUND

A worldwide increase in the prevalence of obesity has been observed in the past three decades, particularly in women of reproductive age. Female obesity has been clearly associated with impaired spontaneous fertility, as well as adverse pregnancy outcomes. Increasing evidence in the literature shows that obesity also contributes to adverse clinical outcomes following in vitro fertilization (IVF) procedures. However, the heterogeneity of the available studies in terms of populations, group definition and outcomes prevents drawing firm conclusions. A previous meta-analysis published in 2011 identified a marginal but significant negative effect of increased female body mass index (BMI) on IVF results, but numerous studies have been published since then, including large cohort studies from national registries, highlighting the need for an updated review and meta-analysis.

OBJECTIVE AND RATIONALE

Our systematic review and meta-analysis of the available literature aims to evaluate the association of female obesity with the probability of live birth following IVF. Subgroup analyses according to ovulatory status, oocyte origin, fresh or frozen-embryo transfer and cycle rank were performed.

SEARCH METHODS

A systematic review was performed using the following key words: ('obesity', 'body mass index', 'live birth', 'IVF', 'ICSI'). Searches were conducted in MEDLINE, EMBASE, Cochrane Library, Eudract and clinicaltrial.gov from 01 January 2007 to 30 November 2017. Study selection was based on title and abstract. Full texts of potentially relevant articles were retrieved and assessed for inclusion by two reviewers. Subsequently, quality was assessed using the Newcastle-Ottawa Quality Assessment Scales for patient selection, comparability and assessment of outcomes. Two independent reviewers carried out study selection and data extraction according to Cochrane methods. Random-effect meta-analysis was performed using Review Manager software on all data (overall analysis), followed by subgroup analyses.

OUTCOMES

A total of 21 studies were included in the meta-analysis. A decreased probability of live birth following IVF was observed in obese (BMI ≥ 30 kg/m2) women when compared with normal weight (BMI 18.5-24.9 kg/m2) women: risk ratio (RR) (95% CI) 0.85 (0.82-0.87). Subgroups analyses demonstrated that prognosis was poorer when obesity was associated with polycystic ovary syndrome, while the oocyte origin (donor or non-donor) did not modify the overall interpretation.

WIDER IMPLICATIONS

Our meta-analysis clearly demonstrates that female obesity negatively and significantly impacts live birth rates following IVF. Whether weight loss can reverse this deleterious effect through lifestyle modifications or bariatric surgery should be further evaluated.

Impact of Central Obesity on Women with Polycystic Ovary Syndrome Undergoing In Vitro Fertilization

Central obesity (CO) is a defining characteristic of polycystic ovary syndrome (PCOS) and PCOS-induced disorders are likely to be exacerbated in the presence of CO. This study aims to evaluate the impact of CO on infertile women with PCOS undergoing in vitro fertilization (IVF).It is a retrospective and case-control study. One hundred eighty-eight infertile PCOS women undergoing IVF were divided into CO group (n = 70, waist circumference [WC] ≥80 cm) and noncentral obesity (NCO) group (n = 118, WC <80 cm). Baseline characteristics, parameters of ovarian stimulation and laboratory, and pregnancy outcomes were compared between two groups. After controlling for body mass index (BMI), WC positively correlated with fasting insulin (r = 0.210, p = 0.007), homeostatic model assessment for insulin resistance (r = 0.249, p = 0.006) and free androgen index (r = 0.249, p = 0.006). Compared with NCO group, CO group had significantly increased endocrine and metabolic disorders and needed significantly higher dose of gonadotropins, longer duration of ovarian stimulation (p < 0.05), but had significantly lower peak serum estradiol level (p < 0.01) and less oocytes retrieved (p = 0.032). CO group had significantly lower live birth and implantation rates (53.8% vs. 86.8%, p = 0.001; and 24.3% vs. 36.3%, p = 0.019, respectively) and higher early spontaneous miscarriage rate (38.5% vs. 7.5%, p = 0.002). For the multivariate analysis, by adjusting for age, BMI, insulin resistance, and hyperandrogenism (HA), CO was significantly independent risk factor for early miscarriage (adjusted relative ratio = 16.87, 95% confidence interval = 2.15-132.70, p = 0.007). CO is associated with insulin resistance, hyperinsulinemia, and HA independent of BMI and is associated with poor pregnancy outcome in infertile women with PCOS undergoing IVF.

Obesity and Outcome of Assisted Reproduction in Patients With Polycystic Ovary Syndrome

Assisted reproduction, including in vitro fertilization and intracytoplasmic sperm injection, is increasingly being used for the management of infertility in patients with polycystic ovary syndrome (PCOS). However, there are limited data regarding the association between obesity and the outcome of assisted reproduction in this specific population as well as on the effects of weight loss. The aim of the present review is to summarize the existing evidence on the association between obesity and the outcome of assisted reproduction in patients with PCOS. Accumulating data suggest that obesity is associated with lower pregnancy and live birth rates in patients with PCOS who are undergoing assisted reproduction therapy. However, it remains unclear whether weight loss improves the outcome of this therapy. Notably, recent guidelines state that the health benefits of postponing pregnancy to achieve weight loss must be balanced against the risk of declining fertility with advancing age. Therefore, if weight loss is not achieved within a reasonable time period, assisted reproduction therapy should be offered in adequately selected patients with PCOS, regardless of the presence of obesity.

Polycystic ovary syndrome throughout a woman's life

Polycystic ovary syndrome (PCOS) is the most common endocrine disorder among reproductive-aged women and the main cause of infertility due to anovulation. However, this syndrome spans the lives of women affecting them from in-utero life until death, leading to several health risks that can impair quality of life and increase morbidity and mortality rates. Fetal programming may represent the beginning of the condition characterized by hyperandrogenism and insulin resistance which leads to a series of medical consequences in adolescence, adulthood, and old age. Menstrual and fertility problems evolve into metabolic complications as age advances. An early and precise diagnosis is important for an adequate management of PCOS, especially at the extreme ends of the reproductive lifespan. However, many different phenotypes are included under the same condition, being important to look at these different phenotypes separately, as they may require different treatments and have different consequences. In this way, PCOS exhibits a great metabolic complexity and its diagnosis needs to be revised once again and adapted to recent data obtained by new technologies. According to the current medical literature, lifestyle therapy constitutes the first step in the management, especially when excess body weight is associated. Pharmacotherapy is frequently used to treat the most predominant manifestations in each age group, such as irregular menses and hirsutism in adolescence, fertility problems in adulthood, and metabolic problems and risk of cancer in old age. Close surveillance is mandatory in each stage of life to avoid health risks which may also affect the offspring, since fetal and post-natal complications seem to be increased in PCOS women.

Impact of insulin resistance and obesity on intracytoplasmic sperm injection outcomes in young women with polycystıc ovary syndrome

OBJECTIVE

To examine effects of body mass index (BMI) and insulin resistance (IR) on the in vitro fertilization (IVF) outcomes in women with polycystic ovary syndrome (PCOS).

METHODS

A total of 106 women with PCOS who underwent intracytoplasmic sperm injection were investigated. The patients were stratified into groups according to their BMI [healthy weight: BMI <25 kg/m2 (n=51), overweight: ≤25-29.9 kg/m2 (n=27), and obese: ≥30 kg/m2 (n=28)]. Secondly, the patients were classified based on the presence of IR (IR was considered to be present if homeostatic model assessment-IR was >2.5). The main outcome measures were reproductive and IVF outcomes with respect to BMI and IR.

RESULTS

The basal hormonal evaluations, such as follicle-stimulating hormone (FSH), luteinizing hormone (LH), LH/FSH, estradiol, testosterone, DHEAS, AMH, and antral follicle counts, were similar between the groups of BMI and IR. The number of retrieved oocytes, MII oocytes, embryo counts, and fertilization and pregnancy rates were similar between lean and overweight/obese PCOS with and without IR. Even though pregnancy and delivery rates per started cycle and embryo transfer were higher in healthy-weight women with PCOS than in overweight/obese patients, it did not reach statistical significance.

CONCLUSION

Reproductive outcomes in women with PCOS according to BMI and IR were similar. Neither BMI nor IR had an independent effect on ovarian response and IVF success in young women with PCOS.

Analyses of optimal body mass index for infertile patients with either polycystic or non-polycystic ovary syndrome during assisted reproductive treatment in China

We observed the effect of body mass index (BMI) on pregnancy outcomes in Chinese patients undergoing assisted reproductive treatment (ART). All the patients were divided into polycystic ovary syndrome (PCOS) group and non-PCOS group, and then according to BMI, each group was subdivided into 6 subgroups: group 1 (BMI < 18 kg/m²), group 2 (18–20 kg/m²), group 3 (20–22 kg/m²), group 4 (22–24 kg/m²), group 5 (24–26 kg/m²) and group 6 (BMI > 26.0 kg/m²). We found that in 20 to 25-year-old patients, the pregnancy rate was not significantly correlated with BMI in PCOS patients; while in non-POCS patients, the pregnancy rate significantly decreased at the BMI cut-off point value of 24–26 kg/m². The pregnancy rate significantly declined at the BMI cut-off point values of 22–24 kg/m² and 18–20 kg/m², respectively in 25 to 35-year-old and in over 35-year-old PCOS patients; while in over 25-year-old non-PCOS patients, no significant correlation between pregnancy rate and BMI was observed. We conclude that for under 25-year-old non-PCOS patients, ART should be performed after BMI is controlled under 26 kg/m². For PCOS patients, if age is 25 to 35 years or over 35 years, BMI should be controlled below 24 kg/m² or below 20 kg/m², respectively.

Enhanced Inflammatory Transcriptome in the Granulosa Cells of Women With Polycystic Ovarian Syndrome

CONTEXT

Polycystic ovarian syndrome (PCOS), the most common endocrine disorder of reproductive-aged women, is associated with systemic low-grade inflammation.

OBJECTIVE

We propose that increased or altered intrafollicular inflammatory reactions also occur in periovulatory follicles of PCOS patients.

DESIGN

Gene profiling and quantitative PCR (qPCR) analyses in granulosa-lutein cells (GCs) collected from PCOS and non-PCOS women undergoing in vitro fertilization were compared with serum and follicular fluid (FF) levels of cytokines and chemokines.

SETTING

This was a university-based study.

PATIENTS

Twenty-one PCOS and 45 control patients were recruited: demographic, hormone, body mass index, and pregnancy outcomes were abstracted from patient data files.

INTERVENTIONS

GC cytokine/chemokine mRNAs were identified and analyzed by gene-chip microarrays/qPCR before and after culture with human chorionic gonadotropin, DHT, IL-6, or IL-8; serum/FF cytokine levels were also analyzed.

MAIN OUTCOME MEASURES

Relative serum/FF cytokine levels and GC cytokine expression before and after culture were compared and related to body mass index.

RESULTS

The following results were found: 1) PCOS GCs express elevated transcripts encoding cytokines, chemokines, and immune cell markers, 2) based on gene profiling and qPCR analyses, obese PCOS patients define a distinct PCOS disease subtype with the most dramatic increases in proinflammatory and immune-related factors, and 3) human chorionic gonadotropin and DHT increased cytokine production in cultured GCs, whereas cytokines augmented cytokine and vascular genes, indicating that hyperandrogenism/elevated LH and obesity in PCOS women augment intrafollicular cytokine production.

CONCLUSIONS

Intrafollicular androgens and cytokines likely comprise a local regulatory loop that impacts GC expression of cytokines and chemokines and the presence of immune cells; this loop is further enhanced in the obese PCOS subtype.

Avoiding OHSS: Controlled Ovarian Low-Dose Stimulation in Women with PCOS

The polycystic ovary syndrome is a common endocrine disorder which influences outcome and potential risks involved with controlled ovarian stimulation for artificial reproductive techniques (ART). Concrete practical recommendations for the dosage of gonadotropins, the preferred protocol and preventive methods to avoid ovarian hyperstimulation syndrome (OHSS) are lacking. We present retrospective data of 235 individually calculated gonadotropin low-dose stimulations for ART in a single center from 2012 to 2014. Clinical data and outcome parameter of patients diagnosed with PCOS according to Rotterdam criteria (n = 39) were compared with patients without PCOS (n = 196). The starting dose of gonadotropins was individually calculated depending on patients' age, BMI, ovarian reserve, ovarian response in previous cycles, and diagnostic criteria of PCOS. Mean age and duration of infertility did not differ between the groups, whereas mean BMI (p = 0.007) and AMH (p < 0.001) were higher in the PCOS-group. A lower mean FSH-starting and maximum dose was administered to women with PCOS (p < 0.001). The biochemical pregnancy rate of 42.4 % and the clinical pregnancy rate of 32.2 % for PCOS-patients did not differ from those of the control group (42.2 % and 34.4 % respectively). Neither mild, nor moderate or severe manifestation of OHSS occurred significantly more often in patients with PCOS. Our study supports the use of a calculated low-dose FSH-stimulation strategy in ART for patients with PCOS. Further randomized clinical trials should confirm this strategy and lead to define individual risk factors for OHSS, which can be used for recommendation of safer ART-techniques like in vitro maturation.

Effect of body mass index and age on in vitro fertilization in polycystic ovary syndrome

OBJECTIVE

The aim of this study was to investigate age-related variations in the effect of body mass index (BMI) on in vitro fertilization (IVF) outcomes.

MATERIAL AND METHODS

This was a cohort study conducted by retrospectively investigating the IVF cycles of 653 polycystic ovary syndrome (PCOS) patients under the age of 40 years who were diagnosed based on the Rotterdam criteria in a private IVF clinic between 2005 and 2015. The study included data from 653 IVF cycles of PCOS patients. The patients were classified into three groups based on their BMI, i.e., normal weight (n=299), overweight (n=208), and obese (n=146). The patients were also grouped by age: 562 patients were under the age of 35 years and 91 patients were above the age of 35 years. Then, BMI- and age-related variations in the IVF cycle parameters and clinical pregnancy rates of patients with PCOS were investigated. The Mantel-Haenszel Chi-square statistical assessment method was used to determine whether the effect of BMI on IVF outcomes varies with age.

RESULTS

Variations in cycle variables with BMI and age showed that IVF cycles were negatively affected by increases in obesity and age. Clinical pregnancy rates were found to be lower in the obese group than in the other groups, particularly in the age group above 35 years; however, this difference could not be proven statistically.

CONCLUSION

The present study evaluated obesity and clinical pregnancy rates in IVF cycles in PCOS patients according to age groups, and particularly in the obese group, the clinical pregnancy rates were observed to be lower in the age group ≥35 years than in the other BMI groups; however, this difference was found to be statistically insignificant.

Evaluation of relationship between serum levels of anti-müllerian hormone, androgen, and insulin resistant with retrieval oocytes in overweight patients with polycystic ovary syndrome

Background:

This study aimed to find a correlation between increased body mass index (BMI), insulin resistance (IR), hyperandrogenism, and anti-mullerian hormone (AMH) serum levels with the number of follicles retrieved in polycystic ovary syndrome (PCOS) patients.

Materials and Methods:

The descriptive study was taken on 80 women with average ages of 20-35 years at Alzahra Hospital of Tabriz-Iran who referred for in vitro fertilization. Patients were divided into four groups and serum levels of AMH, testosterone and IR were evaluated at the puncture time.

Results:

The mean number of follicle retrieved was higher in PCOS (P < 0.05) group than non-PCOS patients. There was a negative significant correlation of follicle number with BMI (r = −0.26, P < 0.05). The ratio of follicle numbers in PCOS/overweight group decreased in comparison to PCOS/normal weight group (−30%, P < 0.05) while the follicle numbers in non-PCOS/overweight patients decreased in comparison with non-PCOS/normal weight (−26%, P > 0.05). There was a significant negative association between BMI with AMH (r = −0.59, P < 0.05), BMI with the follicle numbers (r = −0.2, P < 0.05) and a positive association BMI with -IR (r = 0.3, P < 0.05), but there wasn’t a significant correlation between BMI with testosterone (r = 0.1, P < 0.5).

Conclusion:

Our finding provides that increasing BMI with direct effect on AMH levels and IR can affect the number of follicles, which are retrieved in these patients.

Distinct localisation of lipids in the ovarian follicular environment

Obesity is associated with decreased pregnancy rates due, in part, to compromised oocyte quality. The aim of the present cross-sectional study of 84 women undergoing oocyte aspiration was to: (1) compare insulin, lipids and glucose in follicular fluid with serum; (2) determine whether increased body mass index (BMI) and waist circumference, hyperinsulinaemia, dyslipidaemia or metabolic syndrome altered follicular fluid metabolites; and (3) determine relative lipid content in oocytes to reveal any influence of these parameters on oocyte quality and IVF outcomes. Insulin, glucose, triglyceride and free fatty acids were lower in follicular fluid than blood and not strictly correlated between compartments. Insulin, glucose and triglyceride positively correlated with increasing BMI and waist circumference in blood and follicular fluid. Insulin increased in follicular fluid in association with metabolic syndrome. Free fatty acid composition analysis showed saturated fatty acids, particularly palmitic and stearic acid, to be more prevalent in follicular fluid than blood. There were no associations between follicular fluid metabolites or oocyte lipid content and clinical outcomes; however, oocyte immaturity correlated with follicular fluid glucose and fatty acid levels, as well as metabolic syndrome. The present study confirms that the human ovarian follicular environment surrounding the oocyte exhibits a unique metabolite profile compared with blood, with distinct localisation of lipids within follicular fluid and oocytes.

Obesity is not associated with the poor pregnancy outcome following intracytoplasmic sperm injection in women with polycystic ovary syndrome

OBJECTIVE

To determine if body mass index has an effect on the outcome of in vitro fertilization in patients with polycystic ovary syndrome undergoing controlled ovarian hyperstimulation.

MATERIAL AND METHODS

The study included 337 cycles. Patients were stratified into the following 3 groups: normal weight, overweight, and obese. The primary outcome measures were response to ovarian hyperstimulation, the fertilization rate, the implantation rate, and the clinical and ongoing pregnancy rates.

RESULTS

Total gonadotropin consumption increased, and the number of retrieved oocytes decreased as the body mass index increased. The implantation rate and clinical pregnancy rate were similar in all 3 groups. In response to the mid-luteal long protocol, the cycle cancellation rate was lower and the number of retrieved oocytes was higher in the overweight and obese groups, as compared to the antagonist protocol.

CONCLUSION

The body mass index did not affect the outcome of in vitro fertilization in women with polycystic ovary syndrome. Additional research is required to better understand the role of stimulation protocols on the cycle outcome.

Effect of body mass index on in vitro fertilization outcomes in women with polycystic ovary syndrome

OBJECTIVE

The objective of the investigation was to study the effect of body mass index (BMI) on in vitro fertilization (IVF) outcomes within a polycystic ovary syndrome (PCOS) population.

STUDY DESIGN

This was a retrospective cohort study including 101 cycles from 79 women younger than 40 years old with a clinically documented diagnosis of PCOS by Rotterdam criteria undergoing IVF at a university-based infertility clinic from 2001 through 2010. All participants were stratified by BMI calculated from height and weight recorded within 3 months of cycle start: lean (18.7-24.9 kg/m(2), n = 51), overweight (25-29.9 kg/m(2), n = 19), and obese (≥30 kg/m(2), n = 31). Linear, logistic, and Poisson regressions were used as appropriate to estimate the effect of a range of BMIs on IVF outcomes while adjusting for potential confounders.

RESULTS

Obese PCOS women had 69% lower odds of clinical pregnancy per cycle start (odds ratio [OR], 0.31; 95% confidence interval [CI], 0.11-0.86; P = .02) and 77% lower odds of clinical pregnancy per embryo transfer (OR, 0.23; 95% CI, -0.08 to 0.68; P = .008) compared with lean PCOS women. Among obese PCOS women, the odds of live birth were 71% lower per cycle start (OR, 0.29; 95% CI, 0.10-0.84; P = .02) and 77% lower per embryo transfer (OR, 0.23; 95% CI, 0.07-0.71; P = .01) compared with lean PCOS women. There was a trend toward decreased ovarian hyperstimulation syndrome incidence with increasing BMI among women with PCOS: 19.6% in lean, 10.5% in overweight, and 3.2% in obese.

CONCLUSION

PCOS is a broad syndrome, with our results demonstrating 2 distinct populations, lean and obese, which have different IVF outcomes including ovarian hyperstimulation syndrome risk profiles. This information is important for clinicians because it informs treatment decisions.

The effects of being overweight and obese on female reproduction: a review

Obesity is a major international problem related to many reproductive health problems including polycystic ovary syndrome (PCOS). This article reviews the evidence of being overweight and its effect on female reproduction. The fecundity of obese women is lower than normal weight women, but there is no absolute consensus about the effect of obesity on infertility treatment. The obese patient might have oocyte, hormone, metabolic and endometrial dysfunction affecting reproduction. Insulin and leptin may be some of the answers explaining anovulation during obesity leading to infertility. Moreover, the follicular glucose and lipids which are important for oocyte development also increase in the obese patient and these might have an effect on oocyte quality because studies in mice have revealed that the obesity affects follicular cell stress and oocyte lipids. Overall, obesity affects female reproduction by disturbing the general body metabolism, hormone metabolism and the follicular environment.

[Impact of polycystic ovary syndrome on oocyte and embryo quality]

This review analyzes the literature concerning oocyte and embryo quality, in case of in vitro fertilization (IVF) for women with polycystic ovary syndrome (PCOS). Alterations in oocyte quality, and consequently in embryo quality, may be due to endocrine and intra-ovarian paracrine changes. However, most of publications find similar biological and clinical results after IVF, with or without microinjection, for women with PCOS compared to those obtained in control populations. Subgroups of more pejorative outcome probably exist within PCOS population. Finally, obesity, which is frequent in PCOS, is clearly deleterious, and multidisciplinary care, including lifestyle modifications, is then needed.

Obesity, assisted reproductive technology, and early preterm birth--Florida, 2004-2006

Florida resident birth certificates for 2004-2006 were linked to the Centers for Disease Control and Prevention's National ART Surveillance System and were used to investigate 1) whether the association of assisted reproductive technology (ART) with preterm birth varies by prepregnancy body mass index and 2) whether the association varies by plurality. Preterm birth was defined as early preterm birth (gestation <34 weeks) and late preterm birth (gestation 34-36 weeks). Descriptive statistics and multinomial logistic regression were used to explore maternal and infant differences by ART status and plurality. Of 581,403 women included in the study, 24.0% were overweight, 18.6% were obese, 7.3% had late preterm birth, 2.6% had early preterm birth, and 0.67% conceived through ART. Among singleton births, ART was associated with increased early preterm birth risk among underweight (odds ratio (OR) = 2.94, 95% confidence interval (CI): 1.27, 6.81), overweight (OR = 1.75, 95% CI: 1.12, 2.72), and obese (OR = 2.37, 95% CI: 1.51, 3.71) women. Among twins, ART was significantly associated with increased risk among overweight (OR = 1.61, 95% CI: 1.12, 2.32) and obese (OR = 1.85, 95% CI: 1.18, 2.90) women. Differences in the associations between ART and early preterm birth by body mass index and plurality warrant further investigation.

The impact of obesity on oocytes: evidence for lipotoxicity mechanisms

Obesity can have detrimental effects on pregnancy rates in natural conceptions and also in women undergoing IVF or intracytoplasmic sperm injection (ICSI). This review summarises the most recent clinical literature investigating whether obesity impacts oocyte quality and early embryo growth. In other tissues, obesity leads to lipotoxicity responses including endoplasmic reticulum stress, mitochondrial dysfunction and apoptosis. Recent reports indicate that lipotoxicity is a mechanism by which obesity may impact oocyte quality.

Complications and outcome of assisted reproduction technologies in overweight and obese women

BACKGROUND

Based on a presumed negative impact of overweight and obesity on reproductive capacity and pregnancy outcome, some national guidelines and clinicians have argued that there should be an upper limit for a woman's BMI to access assisted reproductive technologies (ART). However, evidence on the risk of complications or expected success rate of ART in obese women is scarce. We therefore performed a systematic review on the subject.

METHODS

We searched the literature for studies reporting on complications or success rates in overweight and obese women undergoing ART. Articles were scored on methodological quality. We calculated pooled odds ratios (ORs) to express the association between overweight and obesity on the one hand, and complications and success rates of ART on the other hand. We only pooled results if data were available per woman instead of per cycle or embryo transfer.

RESULTS

We detected 14 studies that reported on the association between overweight and complications during or after ART, of which 6 reported on ovarian hyperstimulation syndrome (OHSS), 7 on multiple pregnancies and 6 on ectopic pregnancies. None of the individual studies found a positive association between overweight and ART complications. The pooled ORs for overweight versus normal weight for OHSS, multiple pregnancy and ectopic pregnancy were 1.0 [95% confidence interval (CI) 0.77-1.3], 0.97 (95% CI 0.91-1.04) and 0.96 (95% CI 0.54-1.7), respectively. In 27 studies that reported on BMI and the success of ART, the pooled ORs for overweight versus normal weight on live birth, ongoing and clinical pregnancy following ART were OR 0.90 (95% CI 0.82-1.0), 1.01 (95% CI 0.75-1.4) and OR 0.94 (95% CI 0.69-1.3), respectively.

CONCLUSIONS

Data on complications following ART are scarce and therefore a registration system should be implemented in order to gain more insight into this subject. In the available literature, there is no evidence of overweight or obesity increasing the risk of complications following ART. Furthermore, they only marginally reduce the success rates. Based on the currently available data, overweight and obesity in itself should not be a reason to withhold ART.

Overweight and obesity negatively affect the outcomes of ovarian stimulation and in vitro fertilisation: a cohort study of 2628 Chinese women

OBJECTIVE

To explore the effects of overweight and obesity on the outcomes of in vitro fertilisation (IVF) in Chinese infertile patients.

STUDY DESIGN

A retrospective cohort study was carried out in 2222 normal weight (18.5 <or= BMI < 25), 379 overweight (25 <or= BMI < 30) and 27 obese (BMI >or= 30) women who underwent their first IVF cycles between 2002 and 2008. Cycle characteristics and IVF outcomes were analysed.

RESULTS

Obese women required significantly higher dose of rFSH (3272 IU vs. 2587 IU, p < 0.001) and days of stimulation (11.89 +/- 4.57 vs. 10.42 +/- 2.03, p < 0.001), but exhibited less oocytes retrieved and significantly lower fertilisation rate (54.1% vs. 61.1%, p < 0.001) than normal weight women. Compared with normal weight women, overweight women displayed significantly less oocytes retrieved (12.98 +/- 6.91 vs. 14.49 +/- 7.96, p < 0.001), lower fertilisation rate (60.8 +/- 23.3 vs. 61.1 +/- 23.0, p < 0.001), less cleavaged embryos (7.55 +/- 4.86 vs. 8.67 +/- 5.90, p < 0.001), less high-grade embryos (4.65 +/- 3.96 vs. 5.59 +/- 4.81, p < 0.001) and cryopreserved embryos (4.44 +/- 4.55 vs. 5.49 +/- 5.55, p < 0.001). All parameters of pregnancy outcomes, including pregnancy rate, miscarriage rate and live birth rate, were comparable among three groups.

CONCLUSIONS

Overweight and obesity are related with impared ovarian response, and negatively affect the outcomes of IVF.

The adverse effects of obesity on conception and implantation

Whilst many multiparous women are obese (body mass index >30 kg/m(2)), obesity has been associated with impaired fecundity; however, the mechanism which links obesity to reduced fertility remains to be fully elucidated. Obese women, particularly those with central obesity, are less likely to conceive per cycle. Obese women suffer perturbations to the hypothalamic-pituitary-ovarian axis, menstrual cycle disturbance and are up to three times more likely to suffer oligo-/anovulation. A fine hormonal balance regulates follicular development and oocyte maturation, and it has been observed that obesity can alter the hormonal milieu. Leptin, a hormone produced by adipocytes, is elevated in obese women, and raised leptin has been associated with impaired fecundity. Obesity impairs ovulation but has also been observed to detrimentally affect endometrial development and implantation. The expression of polycystic ovary syndrome (PCOS) is regulated, in part, by weight, and so obese women with PCOS often have a more severe phenotype and experience more subfertility. Obesity also impairs the response of women to assisted conception treatments. Weight loss through lifestyle modification or bariatric surgery has been demonstrated to restore menstrual cyclicity and ovulation and improve the likelihood of conception. In this article, we will discuss the effect of obesity upon key reproductive mechanisms and its relation to fertility treatments.

Polycystic Ovary Syndrome, Obesity and Reproductive Implications

Polycystic ovary syndrome (PCOS) is one of the most common causes of female infertility, affecting 5–10% of women of reproductive age. The syndrome is characterized by anovulation, hyperandrogenism and polycystic ovaries. Furthermore, PCOS is associated with insulin resistance and obesity, which is present in approximately 50% of women with PCOS. Reproductive function in women with PCOS is strongly dependent on bodyweight and metabolic status. Obesity is associated with an increased risk of infertility and may also have a negative influence on pregnancy outcome. Considering the worldwide epidemic of obesity, clinical problems relating to PCOS may worsen and increase in frequency. Lifestyle interventions resulting in weight loss comprise the most successful strategy to improve symptoms of PCOS. However, many patients fail to lose weight or may quickly regain weight. It is an important challenge to develop effective lifestyle programs and adjuvant pharmacologic treatments in order to improve reproductive and metabolic health among women with PCOS.