Increased body mass index has a deleterious effect on in vitro fertilization outcome

Pregnancy outcomes after superovulation-intrauterine insemination (SO-IUI) using gonadotropins versus letrozole in the obese population

PURPOSE

To compare fertility outcomes of obese patients (body mass index [BMI] ≥ 30 kg/m2) undergoing superovulation and intrauterine insemination (SO-IUI) using gonadotropins versus letrozole.

METHODS

A single centre retrospective cohort study of obese patients undergoing SO-IUI using gonadotropins or letrozole between January/2019 and June/2022. Primary outcome was clinical pregnancy rate (intrauterine pregnancy with positive fetal heart rate). Secondary outcomes included rates of multifollicular development, multiple pregnancy, spontaneous abortion and cycle cancellation. Subgroup analysis was done stratifying by obesity class. A multivariate logistic regression model was used for primary/secondary outcomes, adjusting for clinically determined covariates.

RESULTS

Out of 802 total identified SO-IUI cycles, 715 cycles were completed (518-gonadotropins and 197-letrozole cycles). The clinical pregnancy rates were not significantly different in obese patients undergoing SO-IUI with gonadotropins versus letrozole when adjusted for age, gravidity, parity, cause of infertility, IUI cycle number, endometrial thickness, sperm source and post-wash motile sperm count (adjusted odds ratio [aOR] 1.37, 95% confidence interval [CI] 0.72-2.59). Similarly, no significant associations were found in spontaneous abortion (aOR1.46, 95%CI 0.42-5.08), multiple pregnancy (aOR1.33, 95%CI 0.20-8.88) or cancellation rates (OR0.89, 95%CI 0.55-1.45) between the two groups. The rates of multifollicular development were also comparable between the two groups (aOR0.51, 95% CI 0.19-1.38). For cycles involving gonadotropins, higher BMI classes required higher total gonadotropin dose (p < 0.001).

CONCLUSION

After adjusting for patient and cycle factors, gonadotropins and letrozole led to comparable odds of achieving pregnancy in obese patients undergoing SO-IUI. Future research in the obese population will help to better understand how to optimize fertility treatments for this growing population.

A higher preconceptional paternal body mass index influences fertilization rate and preimplantation embryo development

Background

Obesity is a worldwide problem affecting the health of millions of people throughout the life course. Studies reveal that obesity impairs sperm parameters and epigenetics, potentially influencing embryonic development.

Objective

To investigate the association between preconceptional paternal body mass index (BMI) and embryo morphokinetics using a time‐lapse incubator and in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI) outcomes.

Materials and methods

Participants were recruited from a tertiary hospital in this prospective periconceptional cohort study. A total of 211 men were included: 86 with normal weight (BMI < 25.0), 94 overweight (BMI 25–29.9), and 41 obese (BMI ≥ 30). These men were part of a couple that underwent IVF/ICSI treatment with ejaculated sperm after which 757 embryos were cultured in a time‐lapse incubator. The main outcome parameters consisted of fertilization rate, embryo developmental morphokinetics, embryo quality assessed by a time‐lapse prediction algorithm (KIDScore), and live birth rate.

Results

A higher paternal BMI was associated with faster development of the preimplantation embryo, especially during the first cleavage divisions (t2: −0.11 h (p = 0.05) and t3: −0.19 h (p = 0.01)). Embryo quality using the KIDScore was not altered. The linear regression analysis, after adjustment for confounders (paternal age, ethnicity, smoking, alcohol use, education, total motile sperm count, and maternal age and BMI), showed an inverse association between paternal BMI and fertilization rate (effect estimate: −0.01 (p = 0.002)), but not with the live birth rate.

Discussion and conclusion

Our data demonstrate that a higher preconceptional paternal BMI is associated with a reduced fertilization rate in IVF/ICSI treatment. Our findings underline the importance of a healthy paternal weight during the preconception period.

Racial disparities in frozen embryo transfer success

PURPOSE

To compare pregnancy and birth outcomes after frozen embryo transfers (FETs) among White, Black, and Asian women and evaluate the effect of patient, protocol, and cycle characteristics on success.

METHODS

A retrospective chart review identified women who underwent an autologous FET at an academic fertility center between January 2013 and March 2020.

RESULTS

White, Black, and Asian women completed 1,181 (71.7%), 230 (14.0%), and 235 (14.3%) cycles, respectively. Black women were significantly less likely to achieve a positive hCG level (AOR 0.66, 95% CI 0.49-0.90), clinical pregnancy (AOR 0.71, 95% CI 0.53-0.97), and live birth (AOR 0.65, 95% CI 0.47-0.89) compared to White women after adjusting for possible confounders. There were no differences in the aforementioned outcomes when looking at cycles completed by Asian versus White women. When comparing outcomes by endometrial preparation protocol, significant differences were seen amongst the three groups for live birth rates following natural cycle FETs (52.36%, 25.81%, and 44.19% for White, Black, and Asian women, respectively, p = 0.02), a difference not appreciated after programmed FETs.

CONCLUSION

Black race is associated with significantly worse pregnancy and live birth rates following FET when compared to White race. Additionally, significant differences in live birth rates among White, Black, and Asian women exist following natural cycle FET versus programmed FET. These disparities in success are not only important for patient counseling, but also when determining management strategies to improve fertility rates among minority women.

Impact of body mass index (BMI) on the success rate of fresh embryo transfer in women undergoing first in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI) treatment

OBJECTIVE

To investigate the impact of body mass index (BMI) on the success rate and prenatal outcomes of fresh embryo transfer in women undergoing their first in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI) treatment.

METHODS

It is a post-hoc analysis of a prospective observational cohort study. 2569 Chinese women were grouped in quintiles of BMI and according to the official Chinese classification of body weight. IVF/ICSI and pregnancy outcomes were compared between groups.

RESULTS

BMI was not associated with IVF/ICSI pregnancy outcomes including hCG positive rate, clinical pregnancy rate, implantation rate, ectopic pregnancy rate, ongoing pregnancy rate, early miscarriage rate, and live birth rate. However, it was negatively related to some pregnancy complications such as gestational diabetes mellitus (GDM) and hypertension. Additionally, the proportion of Cesarean-section was increased with BMI. As for prenatal outcomes, the current results showed no statistical difference in the number of male and female newborn, the proportion of low live birth weight (<2500 g), macrosomia (≥4000 g) (both in all live birth and full-term live birth), and premature delivery (<37 weeks).

CONCLUSIONS

The current study showed that BMI was not associated with embryo transfer outcomes after fresh embryo transfer in women undergoing their first IVF/ICSI treatment, whereas BMI was associated with GDM and gestational hypertension.

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.

Bodyweight status misperception among reproductive-aged women in primary care settings

INTRODUCTION

It is common, and many international and local studies confirm this, that women of reproductive age misperceive their body-weight status. This phenomenon can lead to their being less likely to adopt a healthy lifestyle which later exposes them to increased health problems and risks including those of a gynecological and obstetric nature. Generally, there have been inconsistent findings concerning the association between the self-perceived weight status and sociodemographic factors, physical activities, and previous weight loss attempts of women of reproductive age in an Asian population like Malaysia.

OBJECTIVE

This study aimed to determine the factors associated with body weight status misperception among reproductive-aged women at a primary care setting in Malaysia.

METHODS

This is a cross-sectional study conducted at Klinik Kesihatan Durian Tunggal in 2016-2017. The questionnaire included questions on the perception of weight status, sociodemographic factors, smoking status, level of physical activity, and weight loss attempts. Logistic regressions were used for statistical analysis to examine the association between body weight status misperception and related factors.

RESULTS

The study recruited 630 reproductive-aged women. The mean age and SD of the respondents was 32.7 + 8.9 years, and 84% of the respondents were Malays. More than three-quarters of the respondents (75.5%, n = 476) had received up to a secondary level of education. The majority of the respondents were in the overweight/obese group (59.4%, n = 374). The mean BMI of the respondents was 27.1 kg/m2 + 6.61. Approximately 65.4% (n = 412) of the respondents had an inactive lifestyle. However, 60% (n = 378) of the respondents reported that they had attempted to reduce their weight in the last year. A total of 141 respondents (22.4%) misperceived their weight status with 113 (80.1% ) of them underestimating their weight status. Women with primary-level education (OR: 3.545, 95% CI: 1.530-8.215, p = 0.003) and secondary-level education (OR: 1.933, 95% CI: 1.065-3.510, p = 0.030) had a greater likelihood of misperceiving their body weight status as compared to those who have a tertiary level of education. Women with no weight loss attempts were also at risk of body weight status misperception (OR: 1.850, 95% CI: 1.195, 2.865, p = 0.006).

CONCLUSION

Bodyweight status misperception among reproductive-aged women was associated with a low level of education and with those who had made no weight loss attempts. Identifying women who are at risk of misperceiving their weight status would enable early counseling on weight management.

Effect of body mass index on intrauterine insemination cycle success

OBJECTIVE

To determine whether body mass index (BMI) affects intrauterine insemination treatment success.

DESIGN

Retrospective cohort study.

SETTING

Academic medical center.

PATIENT(S)

A total of 3,217 intrauterine insemination treatment cycles in 1,306 patients.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Primary outcome was live birth rate stratified by BMI. Secondary outcomes included rates of clinical pregnancy (defined as an intrauterine pregnancy with a heartbeat present on ultrasound), multiple gestation, biochemical pregnancy, missed abortion, ectopic, and spontaneous abortion.

RESULT(S)

Women with BMI 25 to 29.99 kg/m² or ≥30 kg/m² were equally likely to have a live birth as women of normal BMI. Women with BMI ≥30 kg/m² did have a higher likelihood of biochemical pregnancy than women with normal BMI.

CONCLUSION(S)

A BMI between 25 and 29.99 kg/m² or ≥30 kg/m² does not appear to have a negative effect on live birth after intrauterine insemination. Obesity may be associated with a higher risk of biochemical pregnancy after intrauterine insemination.

Blastocyst formation rate for Asians versus Caucasians and within body mass index categories

PURPOSE

There are well-documented racial and ethnic disparities for in vitro fertilization (IVF) outcomes, including disparities in clinical pregnancy and live birth rate. Obesity has also been associated with an increase in the risk of infertility and reduction in the efficacy of fertility treatment. However, there are limited data regarding the potential effect of race and obesity on in vitro embryo development. The purpose of this study was to determine whether blastocyst formation rates vary with race and body mass index (BMI).

METHODS

This retrospective analysis included 1134 fresh autologous cycles (N = 8266 embryos), which took place from January 2013 to December 2016. Women were categorized as Caucasian, Asian (not Indian), and Indian (South Asian) and by BMI categories (normal, overweight, and obese). Regression analyses were performed using race and BMI as the primary predictor variables and blastocyst formation as the outcome.

RESULTS

Compared to Caucasian, the adjusted OR for blastocyst development was 0.85 (95% CI 0.72-1.00) for Asian women and 1.15 (95% CI 0.95-1.38) for Indian women. Women who were overweight (aOR 0.93; 95% CI 0.77-1.12) or obese (aOR 0.92; 95% CI 0.74-1.12) had similar odds of blastocyst formation comparing to women with normal BMI. Furthermore, analyses examining combined effects of race and BMI revealed no differences in blastocyst formation among Asian or Indian women with varied BMI categories compared to Caucasian women with normal BMI.

CONCLUSION

Blastocyst formation did not differ based on race or BMI.

Association between body mass index and oocyte maturation in patients triggered with GnRH agonist who are at high risk for severe ovarian hyperstimulation syndrome: an observational cohort study

RESEARCH QUESTION

Is body-mass index (BMI) associated with oocyte maturation in women at high risk for developing severe ovarian hyperstimulation syndrome (OHSS) who are triggered with gonadotrophin releasing hormone (GnRH) agonist?

DESIGN

Prospective observational cohort study. A total of 113 patients at high risk for severe OHSS (presence of at least 19 follicles ≥11 mm) pre-treated with gonadotrophin releasing hormone (GnRH) antagonists and recombinant FSH were administered 0.2 mg triptorelin to trigger final oocyte maturation. Patients were classified in two groups depending on their BMI: ΒΜΙ less than 25 kg/m² (n = 72) and ΒΜΙ 25 kg/m² or over (n = 41). Baseline, ovarian stimulation and embryological characteristics, as well as luteal-phase hormone profiles, were compared in patients classified into the two BMI groups. The main outcome measure was the number of mature oocytes.

RESULTS

A significantly higher number of mature (metaphase II) oocytes (19 [18-21] versus 16 [13-20], P = 0.029) was present in women with BMI less than 25 kg/m² compared with those with BMI 25 kg/m² or greater. The number of retrieved oocytes, the number of fertilized oocytes, oocyte retrieval, maturation and fertilization rates were similar in the two groups. A significantly higher dose of recombinant FSH was required for patients with BMI 25 kg/m² or greater compared with patients with BMI less than 25 kg/m² (1875 [1650-2150] IU versus 1650 [1600-1750] IU, P = 0.003) and the two groups displayed different luteal phase hormonal profiles.

CONCLUSIONS

Among women at high risk for developing severe OHSS who are triggered with a standard dose (0.2 mg) of the GnRH agonist triptorelin, women with BMI 25 kg/m² or greater had significantly fewer mature oocytes, required a higher total dose of recombinant FSH compared with women with BMI less than 25 kg/m².

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.

Role of hormonal and inflammatory alterations in obesity-related reproductive dysfunction at the level of the hypothalamic-pituitary-ovarian axis

BACKGROUND

Besides being a risk factor for multiple metabolic disorders, obesity could affect female reproduction. While increased adiposity is associated with hormonal changes that could disrupt the function of the hypothalamus and the pituitary, compelling data suggest that obesity-related hormonal and inflammatory changes could directly impact ovarian function.

OBJECTIVE

To review the available data related to the mechanisms by which obesity, and its associated hormonal and inflammatory changes, could affect the female reproductive function with a focus on the hypothalamic-pituitary-ovarian (HPO) axis.

METHODS

PubMed database search for publications in English language until October 2017 pertaining to obesity and female reproductive function was performed.

RESULTS

The obesity-related changes in hormone levels, in particular leptin, adiponectin, ghrelin, neuropeptide Y and agouti-related protein, are associated with reproductive dysfunction at both the hypothalamic-pituitary and the ovarian levels. The pro-inflammatory molecules advanced glycation end products (AGEs) and monocyte chemotactic protein-1 (MCP-1) are emerging as relatively new players in the pathophysiology of obesity-related ovarian dysfunction.

CONCLUSION

There is an intricate crosstalk between the adipose tissue and the inflammatory system with the HPO axis function. Understanding the mechanisms behind this crosstalk could lead to potential therapies for the common obesity-related reproductive dysfunction.

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.

Optimal parameters for determining the LH surge in natural cycle frozen-thawed embryo transfers

BACKGROUND

There is no consensus on the exact parameters that define the LH surge for natural cycle frozen-thawed embryo transfers (NC-FET). Accurately determining the LH surge would affect the timing, and subsequently the success rates, of embryo transfer. Therefore, the aim of this study was to delineate the optimal levels and relationship for luteinizing hormone (LH) and estradiol in an effort to optimally identify the LH surge in NC-FET.

METHODS

It is a retrospective study that was performed in an academic medical center. Patients who underwent blastocyst NC-FET who either had preimplantation genetic screening (PGS) or were <35 years old but did not undergo PGS (non-PGS) were included in separate analyses. They were divided into two groups: Group A included patients whose LH surge was defined as the first attainment of LH ≥ 17 IU/L during the follicular phase with a ≥30% drop in estradiol levels the following day; group B encompassed patients whose LH level continued to rise and the surge was defined as the highest serum LH level occurring a day after LH ≥ 17 IU/L despite a ≥ 30% drop in estradiol levels. The main outcomes measures were implantation and live birth rates.

RESULTS

Four hundred-seven non-PGS and 284 PGS NC-FET were included. Among non-PGS cycles, group A was associated with significantly higher implantation rates (48.7% vs. 38.1%) and live birth rates (52.9% vs. 40.1%) compared to group B. In contrast, group A and B had comparable live birth rates among PGS cycles.

CONCLUSIONS

Among non-PGS cycles, measuring LH and estradiol levels the day after an LH ≥ 17 IU/L and defining the surge as the first day of LH ≥ 17 IU/L in the context of a ≥ 30% drop in estradiol the following day was associated with better NC-FET outcomes than defining the surge as the day representing the highest serum LH level despite a ≥30% drop in estradiol levels.

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.

Maternal obesity in mice not only affects fresh embryo quality but also aggravates injury due to vitrification

PURPOSE

The aims of the present study are to identify the mechanism(s) whereby obesity impairs fresh embryos and to clarify the effects of vitrification on lipid droplet content within embryos from maternally obese mice.

METHODS

The diet-induced obesity mouse model was established, and the zygotes were captured and cultured to day 3. The eight-cell embryos were selected and divided into fresh and vitrified groups. The blastocysts derived from fresh embryos were used as a control. The expression profiles of endoplasmic reticulum (ER) stress genes (Atf4, Grp78, and Hsp70) and other genes (MnSOD, p53, Gadd45g, caspase-3, IGF-II, ZO-1, and E-cadherin) on day-3 fresh and post-warming eight-cell embryos from obese and control groups were determined. For day-5 fresh blastocysts and blastocysts previously vitrified on day 3, the expression profiles for all of the above genes were also determined.

RESULTS

For the fresh group, obesity significantly upregulated Hsp70, p53, IGF-II, and ZO-1 expression in embryos on day 3 and notably upregulated Atf4, MnSOD, Gadd45g, caspase-3, ZO-1, and E-cadherin expression in blastocysts on day 5. For vitrified ones, obesity significantly upregulated Atf4, MnSOD, and Gadd45g expression in embryos on day 3 and notably upregulated Hsp70 expression and downregulated MnSOD in day 5 blastocysts previously vitrified on day 3.

CONCLUSIONS

Obesity impairs fresh embryos and aggravates embryonic vitrification injury at a molecular level.

Effect of paternal overweight or obesity on IVF treatment outcomes and the possible mechanisms involved

Leukocyte telomere lengths (LTLs) are shorter in obese compared with normal weight people. However, it is not known whether sperm telomere length (STL) is related to obesity. The aim of the study was to evaluate the impact of men’s body mass index (BMI) on STL, embryo quality, and clinical outcomes in couples undergoing IVF. In total, 651 couples were recruited, including 345 men with a normal BMI and 306 men with an overweight BMI (normal BMI group: 20–25 kg/m²; overweight BMI group: >28 kg/m²). We found that couples with male’s BMI over 28 kg/m² exhibited a significantly lower fertilization rate, good-quality embryo rate and clinical pregnancy rate compared to their normal BMI counterparts. The mean STL in the overweight BMI group was also significantly shorter than that of the normal BMI group. The results also showed that individuals with higher BMI had higher ROS (Reactive oxygen species) content and sperm DNA fragmentation rate when compared with normal BMI individuals. Mitochondrial activity was also lower in the overweight BMI group than in the normal BMI group. This is the first report to find that STL is shorter in overweight/obese men, which may account for their poorer treatment outcomes in IVF cycles.

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.

Reproductive outcomes in oocyte donation cycles are associated with donor BMI

STUDY QUESTION

When adjusting for recipient BMI, is donor body mass index (BMI) associated with IVF outcomes in donor oocyte IVF cycles?

SUMMARY ANSWER

Increasing oocyte donor BMI is associated with a reduction in clinical pregnancy and live birth rates.

WHAT IS KNOWN ALREADY

Increased BMI has been associated with suboptimal reproductive outcomes, particularly in assisted reproductive technology (ART) cycles. However, it remains unclear if this association implies an effect of BMI on oocyte quality and/or endometrial receptivity.

STUDY DESIGN, SIZE, DURATION

A retrospective cohort study of two hundred and thirty five consecutive fresh donor oocyte IVF cycles from 1 January 2007 through 31 December 2013 at the Massachusetts General Hospital (MGH) Fertility Center.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Analyses included a total of 202 oocyte donors and 235 total cycles. Following adjustments for recipient BMI, the relationship between donor BMI (categorized into quartiles) and IVF outcomes was assessed.

MAIN RESULTS AND THE ROLE OF CHANCE

In the entire (anonymous and known) donor population, a reduced odds of clinical pregnancy (P-trend = 0.046) and live birth (P-trend = 0.06) was observed with increasing BMI quartile. Compared with quartile 1 (BMI 17.8-21.1), odds ratio (OR) (95% CI) of clinical pregnancy was 0.9 (0.4-2.0), 0.5 (0.2-1.1) and 0.5 (0.2-1.1), and OR of live birth was 1.1 (0.5-2.6), 0.6 (0.3-1.2) and 0.6 (0.3-1.2) for quartiles 2 through 4 respectively. In anonymous donors only, the odds of clinical pregnancy (P-trend = 0.02) and live birth (P-trend = 0.03) also declined as BMI quartile increased. Compared with quartile 1 (BMI 17.8-21.1), odds ratio (OR) (95% CI) of clinical pregnancy was 0.7 (0.3-1.7), 0.5 (0.2-1.1) and 0.4 (0.1-0.9), and OR of live birth was 0.9 (0.4-2.2), 0.5 (0.3-1.2) and 0.4 (0.2-1.1) for quartiles 2 through 4 respectively.

LIMITATIONS, REASONS FOR CAUTION

Limitations include the retrospective design, sample size and data from a single institution. Clinical application may not be limited to oocyte donors, though caution should be used prior to applying these principles to the general population. Data should not be interpreted to mean that all oocyte donors should be restricted to a BMI of less than 21.2 kg/m(2).

WIDER IMPLICATIONS OF THE FINDINGS

Following adjustments for the respective BMI of the oocyte donor and recipient, this study demonstrates an association of preconception BMI with subsequent IVF outcomes. The observations of this study are consistent with prior animal studies, suggest a possible effect of BMI at the oocyte level prior to fertilization and implantation, and warrant further investigation.

STUDY FUNDING/COMPETING INTERESTS

None.

Impact of obesity on infertility in women

The prevalence of obesity and overweight are increasing and have become an epidemic worldwide. Obesity has detrimental influences on all systems, including reproductive health. The prevalence of obesity in infertile women is high, and it is well known that there is an association between obesity and infertility. The relationship between obesity and reproductive functions is still being explored. Overweight women have a higher incidence of menstrual dysfunction and anovulation. Overweight and obese women are at a high risk for reproductive health. The risk of subfecundity and infertility, conception rates, miscarriage rates, and pregnancy complications are increased in these women. They have poor reproductive outcomes in natural as well as assisted conception. These poor reproductive outcomes include assisted reproduction such as ovulation induction, in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI), and ovum donation cycles. Weight loss has beneficial effects on the reproductive outcomes in these patients.

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.

Body composition: A predictive factor of cycle fecundity

Objective

To study the effect of body composition on reproduction in women with unexplained infertility treated with a controlled ovarian hyperstimulation and intrauterine insemination programme.

Methods

This prospective observational study was conducted on 308 unexplained infertile women who were scheduled for a controlled ovarian hyperstimulation and intrauterine insemination programme and were grouped as pregnant and non-pregnant. Anthropometric measurements were performed using TANITA-420MA before the treatment cycle. Body composition was determined using a bioelectrical impedance analysis system.

Results

Body fat mass was significantly lower in pregnant women than in non-pregnant women (15.61±3.65 vs.18.78±5.97, respectively) (p=0.01). In a multiple regression analysis, body fat mass proved to have a stronger association with fecundity than the percentage of body fat, body mass index, or the waist/hip ratio (standardized regression coefficient≥0.277, t-value≥2.537; p<0.05). The cut-off value of fat mass, which was evaluated using the receiver operating characteristics curve, was 16.65 with a sensitivity of 61.8% and a specificity of 70.2%. Below this cut-off value, the odds of the pregnancy occurrence was found to be 2.5 times more likely.

Conclusion

Body fat mass can be predictive for pregnancy in patients with unexplained infertility scheduled for a controlled ovarian hyperstimulation and intrauterine insemination programme.

Intake of high saturated-fat diets disturbs steroidogenesis, lipid metabolism and development of obese-swine conceptuses from early-pregnancy stages

The current study indicates that life-long intake, from early-life, of an obesogenic diet with high saturated-fat (HSF) content induces dyslipidemia (high plasma concentrations of triglycerides in concurrence with low concentrations of HDL-cholesterol) in obese swine with leptin resistance (Iberian sows). In case of pregnancy, ovarian features (ovulatory efficiency and luteal steroidogenesis) of sows fed with HSF are not affected but embryo features are affected at so early stages like 28 days of pregnancy (first quarter), although embryo viability was still not affected. In this way, offspring from HSF sows showed a higher incidence of alterations in their developmental trajectory, mainly due to a higher incidence of growth retardation, in their steroidogenic activity and in their availability of triglycerides and cholesterol. In conclusion, the results obtained in the present study illustrate the deleterious effects of maternal dyslipidemia, induced by the intake of HSF diets, on the oestradiol secretion of the conceptuses at early-pregnancy stages and, thus, on their developmental and metabolic features. This article is part of a Special Issue entitled 'Pregnancy and steroids'.

Assisted reproduction in polycystic ovarian disease: A multicentric trial in India

AIM:

The aim of this study is to compare ovarian response, oocyte, embryo quality, ovarian hyperstimulation syndrome incidence, and pregnancy rates in polycystic ovary syndrome (PCOS) and non-PCOS group.

MATERIALS AND METHODS:

This was a prospective observational study on PCOS carried out in seven assisted reproduction centers in India between August 2008 and July 2010, as part of trial under the Indian Society of Assisted Reproduction. A total of 192 women (77 in the PCOS group and 115 in the non- PCOS group) undergoing in vitro fertilization/intracytoplasmic sperm injection were included. All women had long protocol and recombinant follicle-stimulating hormone stimulation.

ANALYSIS:

The mean number of follicles and oocytes was higher in PCOS group compared with non-PCOS, being 27.2 (±8.8) and 13.6 (±5.3); 15.9 (±6.3) and 10.9 (±6.2), respectively. The recovery rates of oocytes and mature oocytes per follicle were less in the PCOS group which was 64% and 61.1%, respectively as opposed to 80.3% and 74.5%, respectively in non-PCOS group. The total numbers of top-quality embryos were less in the PCOS group.

CONCLUSION:

In PCOS women though the number of follicles was more, recovery of mature oocytes, top-quality embryos was less. Pregnancy rates were comparable in both groups.

Predictive factors influencing pregnancy rates after intrauterine insemination

BACKGROUND

So far, many studies investigated factors that affect pregnancy rates after intrauterine insemination (IUI). Various investigators have not agreed on the nature and ranking of these criteria.

OBJECTIVE

The aim of this study was to assess the predictive factors for pregnancy rate after controlled ovarian hyperstimulation (COH)/ IUI.

MATERIALS AND METHODS

Retrospective study of all patients undergoing IUI at Zeynep Kamil Gynecologic and Pediatric Training and Research Hospital from January 2006 to December 2009. In total 980 IUI cycles in 569 couples were analyzed. All women in the study underwent ovarian stimulation using gonadotropin and IUI was performed 36 h after triggering ovulation. The primary outcome measure was clinical pregnancy rates. Predictive factors evaluated were female age, body mass index (BMI), duration of infertility, type of infertility, follicle stimulating hormone (FSH) level and estradiol (E2) on third day of the cycle, number of preovulatory follicles, endometrial thichness, total motil sperm (TMS) count, and ratio of progressive motile sperm.

RESULTS

The overall clinical pregnancy rate was 4.7%. Among the predictive factors after multivariate logistic regression analysis level of BMI (<25 kg/m²), number of preovulatory follicles (≥2), level of FSH (<9.4 IU/L), level of E2 (<80 pg/ml) and the ratio of progressive motile sperm (>50%) significantly influenced the clinical pregnancy rate.

CONCLUSION

Level of BMI, FSH, estradiol, number of preovulatory follicles and the ratio of progressive motile sperm may determine IUI procedure as optimum treatment model.

ICSI Outcome in Infertile Couples with Different Causes of Infertility: A Cross-Sectional Study

BACKGROUND

Different success rate of Intracytoplasmic Sperm injection (ICSI) has been observed in various causes of infertility. In this study, we evaluated the relation between ICSI outcome and different causes of infertility. We also aimed to examine parameters that might predict the pregnancy success rate following ICSI.

MATERIALS AND METHODS

This cross sectional study included1492 infertile women referred to Infertility Center of Royan Institute between 2010 and 2011. We assigned two groups including pregnant (n=504) and non-pregnant (n=988), while all participants underwent ICSI cycles. All statistics were performed by SPSS program. Statistical Analysis was carried out using Chi-square and t test. Logistic regression was done to build a prediction model in ICSI cycles.

RESULTS

The overall clinical pregnancy rate in our study was 33.9% (n=1492). There was a statistically significant difference in mean serum concentration on day 3 after application of luteinizing hormone (LH) between the pregnant and the non-pregnant groups (p<0.05). However, There were no significant differences between two groups in the serum concentrations on day 3 after application of the following hormones: folliclestimulating hormone (FSH), thyroid-stimulating hormone (TSH), and metoclopramidestimulated prolactin (PRL) . We found no association between different causes of infertility and clinical outcomes . The number of metaphase II (MII) oocytes, embryo transfer, number of good embryo (grade A, B, AB), total dose of gonadotropin, endometrial thickness, maternal age, number of previous cycle were statistically significant between two groups (p<0.05).

CONCLUSION

Our results indicate that ICSI in an effective option in couples with different causes of infertility. These variables were integrated into a statistical model to allow the prediction for the chance of pregnancy following ICSI cycles. It is required that each infertility center gather enough information about the causes of infertility in order to provide more information and better assistance to patients. Therefore, we suggest that physicians prepare adequate training and required information regarding these procedures for infertile couples in order to improve their knowledge.

Parental diet-induced obesity leads to retarded early mouse embryo development and altered carbohydrate utilisation by the blastocyst

Maternal obesity results in reproductive complications, whereas the impact of paternal obesity is unclear. In the present study, the effects of parental obesity on preimplantation embryo cell cycle length and carbohydrate utilisation were investigated. Maternal and paternal obesity were assessed independently by deriving zygotes from normal or obese C57BL/6 female mice mated with normal Swiss male mice (maternal obesity), or from normal Swiss female mice mated with normal or obese C57BL/6 male mice (paternal obesity). Zygotes were cultured in vitro and development was then assessed by time-lapse microscopy and metabolism determined using ultramicrofluorescence. Maternal obesity was associated with a significant delay in precompaction cell cycle kinetics from the 1-cell stage. A significant increase in glucose consumption by embryos from obese compared with normal females occurred after compaction, although glycolysis remained unchanged. Similarly, paternal obesity led to significant delays in cell cycle progression during preimplantation embryo development. However, this developmental delay was observed from the second cleavage stage onwards, following embryonic genome activation. Blastocysts from obese males showed disproportionate changes in carbohydrate metabolism, with significantly increased glycolysis. Overall, metabolic changes were not inhibitory to blastocyst formation; however, blastocyst cell numbers were significantly lower when either parent was obese. These data suggest that both maternal and paternal obesity significantly impacts preimplantation embryo physiology.

Ovarian stimulation in women with high and normal body mass index: GnRH agonist versus GnRH antagonist

In modern society, obesity has become a major health problem and has been associated with impaired fertility. The aim of this study is to assess the role of obesity in women undergoing controlled ovarian hyperstimulation (COH) stimulated either with GnRH agonists or with GnRH antagonists. Records of 463 women undergoing in vitro fertilization (IVF) treatment were reviewed. The influence of body mass index (BMI) on treatment outcome was examined, after accounting for differences in stimulation protocols. In the agonist group (286 patients), the total amount of gonadotropins used was significantly higher in patients with a BMI ≥ 25 kg/m², when compared to those with a normal BMI. The same result was found in the antagonist group (177 patients). No significant differences were found in length of stimulation, number of oocytes retrieved or number of embryos transferred. In both the antagonist and the agonist group, the number of clinical pregnancies was found to be higher in patients with normal BMI, suggesting that obesity could impair the ovarian response to exogenous gonadotropins. Considering the results obtained and the many theoretical advantages of GnRH antagonists, ovarian stimulation with GnRH antagonists is an efficient treatment for both women with normal and high BMI.

Obesity does not aggravate vitrification injury in mouse embryos: a prospective study

BACKGROUND

Obesity is associated with poor reproductive outcomes, but few reports have examined thawed embryo transfer in obese women. Many studies have shown that increased lipid accumulation aggravates vitrification injury in porcine and bovine embryos, but oocytes of these species have high lipid contents (63 ng and 161 ng, respectively). Almost nothing is known about lipids in human oocytes except that these cells are anecdotally known to be relatively lipid poor. In this regard, human oocytes are considered to be similar to those of the mouse, which contain approximately 4 ng total lipids/oocyte. To date, no available data show the impact of obesity on vitrification in mouse embryos. The aim of this study was to establish a murine model of maternal diet-induced obesity and to characterize the effect of obesity on vitrification by investigating the survival rate and embryo developmental competence after thawing.

METHODS

Prospective comparisons were performed between six-eight-cell embryos from obese and normal-weight mice and between fresh and vitrified embryos. Female C57BL/6 mice were fed standard rodent chow (normal-weight group) or a high-fat diet (obese group) for 6 weeks. The mice were mated, zygotes were collected from oviducts and cultured for 3 days, and six-eight-cell embryos were then selected to assess lipid content in fresh embryos and to evaluate differences in apoptosis, survival, and development rates in response to vitrification.

RESULTS

In fresh embryos from obese mice, the lipid content (0.044 vs 0.030, P<0.01) and apoptosis rate (15.1% vs.9.3%, P<0.05)were significantly higher, the survival rate (83.1% vs. 93.1%, P<0.01) on day 5 was significantly lower, and embryo development was notably delayed on days 3-5 compared with the normal-weight group. After vitrification, no significant difference was found between thawed embryos from obese and normal-weight mice in apoptosis, survival, and development rates on days 4 and 5. In both groups, pre- and post-vitrification embryo apoptosis, survival, and development rates were similar.

CONCLUSIONS

This study demonstrated that differences in survival and developmental rates between embryos from obese and normal-weight mice were eliminated after vitrification. Thus, maternal obesity does not aggravate vitrification injury, but obesity alone greatly impairs pre-implantation embryo survival and development.

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.

Influence of body condition on reproductive output in the guinea pig

Reproduction is expensive. Substantial body reserves (i.e. high body condition) are usually required for females to undertake offspring production. In many vertebrates, maternal body condition positively influences reproductive output, and emaciated individuals skip reproduction. However, the impact of extremely high body condition, more specifically obesity, on animal reproductive performance remains poorly understood and research has generated contradictory results. For instance, obesity negatively affects fertility in women, but does not influence reproductive capacity or reproductive output in laboratory rodents. We examined the influence of high body condition on reproductive status and reproductive output in the guinea pig. In captivity, when fed ad libitum, guinea pigs store large amounts of fat tissues and exhibit a tendency for obesity. Our results show that obesity negatively affected reproduction in this species: both the proportion of fertile females and litter size were lower in the fattest females. Therefore, guinea pigs may represent suitable organisms to better understand the negative effect of obesity on reproduction.

Correlation of body mass index with outcome of in vitro fertilization in a developing country

AIMS AND OBJECTIVE

To correlate ovarian response to stimulation and IVF outcome according to the women's body mass index (BMI).

MATERIALS AND METHODS

Records of all patients who underwent IVF cycle in our institution from January 2008 to October 2010 were reviewed retrospectively. Three hundred and twenty-eight patients underwent 342 in vitro fertilization (IVF) cycles or intra-cytoplasmic sperm injection (ICSI) and were divided into four subgroups according to BMI; underweight, BMI < 18.5; normal weight, 18.5-24.9; overweight, 25.0-29.9; and obese, >30.0.

RESULTS

In our study, with increasing BMI negative co-relation was seen with clinical pregnancy rate (CPR) (P value = 0.040). Increased doses of gonadotropins were required with increase in patients BMI (P value = 0.045). In the present study, no difference was seen in the number of oocyte retrieved but a decreased fertilization and cleavage rate was seen with decreased number of cryo-preserved embryos with increasing BMI. This study shows that poorer oocyte quality is seen with increasing BMI which results in reduced CPR. In our study no deleterious effect of low BMI was seen on IVF outcome and CPR.

CONCLUSION

Female obesity impairs IVF outcome potentially by impairing oocyte quality but does not affect ovarian response to stimulation.

Metabolic syndrome and oocyte quality

Metabolic syndrome affects one in four women in the USA, and the incidence is rising every year. Metabolic syndrome is strongly associated with development of coronary artery disease and diabetes. Women of reproductive age are not spared from the complications of metabolic syndrome, which overlaps with obesity and polycystic ovary syndrome (PCOS), both of which are linked to infertility and poor reproductive outcome. Therefore, the relationship between the metabolic syndrome and reproductive dysfunction is an active area of study. In this review, we discuss the animal and human data available to determine if the abnormality is at the level of the ovary and/or endometrium, and discuss the underlying mechanisms causing the associated poor reproductive outcomes.

Paternal diet-induced obesity impairs embryo development and implantation in the mouse

OBJECTIVE

To use a rodent model of male diet-induced obesity (DIO) to examine resultant preimplantation embryo development and implantation rate, as well as fetal and placental growth.

DESIGN

Experimental animal study.

SETTING

University research facilities.

ANIMAL(S)

C57BL/6 male and CBAxC57BL/6 female mice.

INTERVENTION(S)

Male mice were fed a standard rodent chow (lean) or a high-fat diet (obese) for up to 13 weeks. After mating, zygotes were collected and cultured to the blastocyst stage, then assessed or transferred into recipient females.

MAIN OUTCOME MEASURE(S)

Embryo morphology and cell number were assessed and pregnancy outcomes determined at postmortem day 18.

RESULT(S)

Embryos from obese males had reduced cleavage and decreased development to blastocyst stage during culture relative to control males. Blastocysts from obese males implanted at a reduced rate, and the proportion of fetuses that developed was significantly decreased, although fetal and placental weight did not differ between groups.

CONCLUSION(S)

This study demonstrates that paternal obesity impairs preimplantation embryo development and implantation but does not influence gross fetal or placental morphology. It highlights the important contribution that paternal health and lifestyle choices have for achieving a viable pregnancy.

Body mass index impacts in vitro fertilization stimulation

The objective of the study was to prospectively determine if body mass index (BMI) is predictive of live birth rates in patients undergoing IVF. The prospective study enrolled 117 infertility patients with the primary outcome measure being IVF success rates. Mean BMI did not differ between patients with successful outcomes and those without successful outcomes. There was a significant positive correlation between BMI and the number of stimulated follicles (r = 0.19, P < .05). A significant negative correlation between BMI and ampules of gonadotropins used (r = −0.25, P < .01) and between BMI and days of stimulation (r = −0.19, P < .05) was noted. These data demonstrate that women with an elevated BMI produce more follicles, stimulate quicker, and require less gonadotropins during IVF. However, BMI did not have a significant effect on pregnancy outcome rates.

High-quality embryos retain their implantation capability in overweight women

To assess the effect of obesity on implantation rate, pregnancy rate and course of pregnancy in young women undergoing IVF in whom only high-quality embryos were transferred, a cohort study included women attending the IVF unit in 2006-2007 with favourable parameters to achieve pregnancy (<38years, fewer than three IVF cycles, transfer of two high-quality embryos), grouped by body mass index (BMI). Of 230 women, 160 had a BMI ⩽25kg/m(2) (mean 21.6±2.2) and 73 had BMI >25kg/m(2) (mean 29.5±3.7). The overweight group had a higher consumption of gonadotrophins during stimulation. There were no between-group differences in treatment protocols, duration of gonadotrophin stimulation, maximal oestradiol concentrations, endometrial thickness and number of oocytes retrieved/fertilized, or in rates of pregnancy (51.3%, 52.1%), implantation (34.5%, 37.5%), multiple pregnancy, and abortion. Rate of gestational diabetes or pregnancy-induced hypertension was higher in the overweight group (23.3%, 8.2%; P=0.045). Within the overweight group, those with multiple pregnancies were at highest risk (31.3%, 6.9%; P=0.031). In conclusion, implantation and pregnancy rates are not compromised in overweight women when high-quality embryos are transferred. However, in overweight women, pregnancy complications remain high, mainly in those with multiple pregnancies.

Impact of overweight and underweight on IVF treatment in Chinese women

OBJECTIVE

To investigate the effects of body mass index (BMI) on ovarian stimulation and the outcome of IVF or ICSI treatment in Asian population who have different characteristics of BMI from white people.

DESIGN

In this retrospective study, the first fresh cycles of 1107 Chinese women were classified by BMI: underweight (BMI <18.5 kg/m(2)), normal weight (BMI: 18.5-23.9 kg/m(2)) and overweight (BMI >or= 24 kg/m(2)). Dose and days of ovarian simulation, cancelled cycles and number of oocytes collected, fertilisation and embryo utilisation rates and pregnancy outcome were compared among BMI groups.

RESULTS

It showed that overweight women required more ampoules of gonadotrophin (P = 0.002) and had lower peak oestradiol concentration (P = 0.001), increased cycle cancellation due to insufficient follicle development (P = 0.018) and a higher miscarriage rate (10.5 vs. 5.4%, P = 0.018, OR = 2.006 (95% CI: 1.09-3.69, P = 0.025)) compared with normal weight women. However, no differences were found in clinical pregnancy and live-birth rates. Underweight compared with normal weight women showed no differences in ovarian stimulation and IVF outcome although the clinical pregnancy rate was lower (31.1 vs. 37.3%).

CONCLUSION

At a lower cutoff point of BMI in Chinese women, overweight is associated with increased miscarriage risks and impaired response to ovarian stimulation after IVF and ICSI.

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.

Infertility treatment outcome in sub groups of obese population

BACKGROUND

Obesity is a common disorder with a negative impact on IVF treatment outcome. It is not clear whether morbidly obese women (BMI >= 35 kg/m2) respond to treatment differently as compared to obese women (BMI = 30-34.9 kg/m2) in IVF. Our aim was to compare the outcome of IVF or ICSI treatments in obese patients to that in morbidly obese patients.

METHODS

This retrospective cohort study was conducted in a tertiary care centre. Patients inclusion criteria were as follows; BMI >or= 30, age 20-40 years old, first cycle IVF/ICSI treatment with primary infertility and long follicular pituitary down regulation protocol.

RESULTS

A total of 406 obese patients (group A) and 141 morbidly obese patients (group B) satisfied the inclusion criteria. Average BMI was 32.1 +/- 1.38 kg/m2 for group A versus 37.7 +/- 2.99 kg/m2 for group B. Patient age, cause of infertility, duration of stimulation, fertilization rate, and number of transferred embryos were similar in both groups. Compared to group A, group B had fewer medium size and mature follicles (14 vs. 16), fewer oocytes collected (7 vs. 9) and required higher doses of HMG (46.2 vs. 38.5 amps). There was also a higher cancellation rate in group B (28.3% vs. 19%) and lower clinical pregnancy rate per started cycle (19.9% vs. 28.6%).

CONCLUSION

In a homogenous infertile and obese patient population stratified according to their BMI, morbid obesity is associated with unfavorable IVF/ICSI cycle outcome as evidenced by lower pregnancy rates. It is recommended that morbidly obese patients undergo appropriate counseling before the initiation of this expensive and invasive therapy.

Endometrial thickness, Caucasian ethnicity, and age predict clinical pregnancy following fresh blastocyst embryo transfer: a retrospective cohort

BACKGROUND

In-vitro fertilization (IVF) with blastocyst as opposed to cleavage stage embryos has been advocated to improve success rates. Limited information exists on which to predict which patients undergoing blastocyst embryo transfer (BET) will achieve pregnancy. This study's objective was to evaluate the predictive value of patient and cycle characteristics for clinical pregnancy following fresh BET.

METHODS

This was a retrospective cohort study from 2003-2007 at an academic assisted reproductive program. 114 women with infertility underwent fresh IVF with embryo transfer. We studied patients undergoing transfer of embryos at the blastocyst stage of development. Our main outcome of interest was clinical pregnancy. Clinical pregnancy and its associations with patient characteristics (age, body mass index, FSH, ethnicity) and cycle parameters (thickness of endometrial stripe, number eggs, available cleaving embryos, number blastocysts available, transferred, and cryopreserved, and embryo quality) were examined using Student's T test and Mann-Whitney-U tests as appropriate. Multivariable logistic regression models were created to determine independent predictors of CP following BET. Receiver Operating Characteristic analyses were used to determine the optimal thickness of endometrial stripe for predicting clinical pregnancy.

RESULTS

Patients achieving clinical pregnancy demonstrated a thicker endometrial stripe and were younger preceding embryo transfer. On multivariable logistic regression analyses, Caucasian ethnicity (OR 2.641, 95% CI 1.054-6.617), thickness of endometrial stripe, (OR 1.185, 95% CI 1.006-1.396) and age (OR 0.879, 95% CI 0.789-0.980) predicted clinical pregnancy. By receiver operating characteristic analysis, endometrial stripe >or= 9.4 mm demonstrated a sensitivity of 83% for predicting clinical pregnancy following BET.

CONCLUSION

In a cohort of patients undergoing fresh BET, thicker endometrial stripe, Caucasian ethnicity, and younger age are positive predictors of clinical pregnancy after fresh BET. These findings may be useful in clinical management of infertile patients undergoing fresh BET cycles.