Impact of overweight and underweight on IVF treatment in Chinese women

Association of HOMA-IR with unexpected poor ovarian response in non-obese women in poseidon 1: a retrospective cohort study

BACKGROUND

Insulin resistance (IR) is related with adverse outcomes of in vitro fertilization (IVF) in women with obesity, but little is known about the relationship between IR and unexpected poor ovarian response (uPOR) in non-obese subjects with sufficient ovarian parameters (classified as POSEIDON group 1). This research aims to explore the association between the homeostasis model assessment of insulin resistance (HOMA-IR) and uPOR in non-obese women with normal biomarkers of ovarian reserve.

METHODS

The retrospective cohort study was conducted at a fertility center. The main inclusion criteria were age < 35 years, body mass index (BMI) < 28 kg/m2, normal ovarian reserve (anti-Mullerian hormone ≥ 1.2 ng/ml, antral follicle count ≥ 5). Women undergoing the first oocyte retrieval cycle were included consecutively between 2018 until 2023. Patients who have ≤ 9 oocytes retrieved were defined as uPOR. The multivariable logistic model and subgroup analysis were conducted after adjusting confounders.

RESULTS

A total of 6977 cycles were included. The adjusted odds ratio was 1.25 (95% confidence interval [CI], 1.12-1.39) for the increment of Ln HOMA-IR which was taken as a continuous variable. Meanwhile, as a sensitivity analysis, elevated tertile of HOMA-IR exhibited an increase in risk of uPOR for the third tertile (≥ 2.75) when compared with the first tertile (< 1.75) with OR of 1.33 (95%CI, 1.15-1.54). In the subgroup analysis, the positive association remained consistent.

CONCLUSION

Elevated HOMA-IR values is significantly associated with increased risk of uPOR in non-obese women classified as POSEIDON group 1. Our study provided evidence for the adverse influence of IR on the ovarian response during IVF and shed light on the importance of IR measurement at the time of pre-stimulation among non-obese women.

Development and validation of a prediction model for unexpected poor ovarian response during IVF/ICSI

Background

Identifying poor ovarian response (POR) among patients with good ovarian reserve poses a significant challenge within reproductive medicine. Currently, there is a lack of published data on the potential risk factors that could predict the occurrence of unexpected POR. The objective of this study was to develop a predictive model to assess the individual probability of unexpected POR during in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI) treatments.

Methods

The development of the nomogram involved a cohort of 10,404 patients with normal ovarian reserve [age, ≤40 years; antral follicle count (AFC), ≥5; and anti-Müllerian hormone (AMH), ≥1.2 ng/ml] from January 2019 to December 2022. Univariate regression analyses and least absolute shrinkage and selection operator regression analysis were employed to ascertain the characteristics associated with POR. Subsequently, the selected variables were utilized to construct the nomogram.

Results

The predictors included in our model were body mass index, basal follicle-stimulating hormone, AMH, AFC, homeostasis model assessment of insulin resistance (HOMA-IR), protocol, and initial dose of gonadotropin. The area under the receiver operating characteristic curve (AUC) was 0.753 [95% confidence interval (CI) = 0.7257-0.7735]. The AUC, along with the Hosmer-Lemeshow test (p = 0.167), demonstrated a satisfactory level of congruence and discrimination ability of the developed model.

Conclusion

The nomogram can anticipate the probability of unexpected POR in IVF/ICSI treatment, thereby assisting professionals in making appropriate clinical judgments and in helping patients to effectively manage expectations.

Association of HOMA-IR with Ovarian Sensitivity Index in Women Undergoing IVF/ICSI: A Retrospective Cohort Study

BACKGROUND

Insulin resistance (IR) may adversely impact the in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI) outcomes. However, the association of IR with ovarian sensitivity during controlled ovarian hyperstimulation (COH) remains controversial.

PURPOSE

We aimed to explore the association between homeostasis model assessment of insulin resistance (HOMA-IR) and ovarian sensitivity index (OSI).

PATIENTS AND METHODS

In this retrospective cohort study, 7836 patients aged between 20 and 39 years with good ovarian reserve were included consecutively between June 2018 and May 2022. HOMA-IR was calculated to evaluate the degree of IR and OSI was used to measure ovarian sensitivity. Owing to skewed distribution, HOMA-IR and OSI were log e transformed to Ln HOMA-IR and Ln OSI. Smoothing splines were generated by generalized additive models to explore the correlation between Ln HOMA-IR and Ln OSI. Then, the relationship between Ln HOMA-IR and Ln OSI was tested with multivariable linear regression model after adjustments for the potential confounders.

RESULTS

We observed negative association between Ln HOMA-IR and Ln OSI after adjustment for potential confounders by using smoothing spline fitting curves in generalized additive model. In the multivariable linear regression model, after full adjustments, each one unit increase in Ln HOMA-IR was related to reduced Ln OSI values (β = -0.12, 95% CI, -0.15, -0.09). As sensitivity analysis, those who had HOMA-IR of quartile 3 (HOMA-IR 2.33-3.43) and quartile 4 (HOMA-IR ≥3.43) had decreases in Ln OSI values (β = -0.07, 95% CI -0.11, -0.03 and β = -0.18, 95% CI -0.22, -0.13, respectively) when compared with patients in the quartile 1 (HOMA-IR <1.63). Furthermore, stratified and interaction analysis showed a strong inverse association of Ln HOMA-IR with Ln OSI in subgroups of PCOS patients and overweight/obese populations (P-value for interaction <0.0001).

CONCLUSION

HOMA-IR value was negatively associated with the ovarian sensitivity assessed by OSI. Among the PCOS and overweight/obese populations, this inverse relationship may be strong. These findings will increase the understanding of the contribution of IR to the development of decreased ovarian sensitivity within the assisted reproductive technology (ART) setting. It may have implications for optimizing gonadotropin dose manipulation in patients with IR undergoing IVF/ICSI.

Obesity and oocyte quality: Significant implications for ART and Emerging mechanistic insights

The prevalence of obesity in adults worldwide, and specifically in women of reproductive age, is concerning given the risks to fertility posed by the increased risk of type 2 diabetes, metabolic syndrome and other non-communicable diseases. Obesity has a multi-systemic impact in female physiology that is characterized by the presence of oxidative stress, lipotoxicity, and the activation of pro-inflammatory pathways, inducing tissue-specific insulin resistance and ultimately conducive to abnormal ovarian function. A higher body mass is linked to Polycystic Ovary Syndrome, dysregulated menstrual cycles, anovulation, and longer time to pregnancy, even in ovulatory women. In the context of ART, compared to women of normal BMI, obese women have worse outcomes in every step of their journey, resulting in reduced success measured as live birth rate. Even after pregnancy is achieved, obese women have a higher chance of miscarriage, gestational diabetes, pregnancy complications, birth defects, and most worryingly, a higher risk of stillbirth and neonatal death. The potential for compounding effects of ART on pregnancy complications and infant morbidities in obese women has not been studied. There is still much debate in the field on whether these poorer outcomes are mainly driven by defects in oocyte quality, abnormal embryo development or an unaccommodating uterine environment, however the clinical evidence to date suggests a combination of all three are responsible. Animal models of maternal obesity shed light on the mechanisms underlaying the effects of obesity on the peri-conception environment, with recent findings pointing to lipotoxicity in the ovarian environment as a key driver of defects in oocytes that have not only reduced developmental competence but long-lasting effects in offspring health.

Body Mass Index Showed No Impact on the Outcome of In Vitro Fertilization in Progestin-Primed Ovarian Stimulation Protocol

Purpose

To assess whether body mass index (BMI) affects the outcome of in vitro fertilization (IVF) in progestin-primed ovarian stimulation (PPOS) protocol.

Methods

A retrospective study was conducted in the Reproductive Medicine Center, Renmin Hospital of Wuhan University, from June 2016 to June 2017. 636 infertile women who received PPOS protocol in IVF treatment were divided into three groups according to BMI. The data of basic characteristics, embryological outcomes, and cycle characteristics of controlled ovarian stimulation of different groups were collected and studied. Result(s). There was no significant difference in almost all the basic characteristics, embryological outcomes of controlled ovarian stimulation, and cycle characteristics of controlled ovarian stimulation among the three groups. There was a tendency that the duration of infertility was decreased with the increase of patients' weight, although there was no significant difference (P=0.051). However, overweight patients had a higher fertilization rate than normal weight patients and underweight patients (70.3 vs. 67.7 vs. 66.8, P=0.008), but two-pronuclei (2PN) fertilization rate and cleavage rate showed no significant difference among the three groups. Conclusion(s). BMI showed no impact on the outcome of the ovarian stimulation outcome in PPOS protocol. PPOS protocol may benefit overweight patients, for it attains the same effect with normal patients and requires no increase in gonadotropin (Gn) dose and Gn duration.

Association between abnormal body mass index and pregnancy outcomes in patients following frozen embryo transfer: a systematic review and meta-analysis

BACKGROUND

There has been increasing interest in the relationship between body mass index(BMI) and pregnancy outcomes, especially in women undergoing frozen embryo transfer(FET). Several observational studies have been published, but so far with conflicting results.

METHODS

A systematic review and meta-analysis was conducted according to PRISMA guidelines. Pubmed, Embase, Cochrane Library, Clinicaltrails.gov and Web of Science databases were searched based on established search strategy from inception through January 2021.

RESULTS

Twelve studies were eligible. In women following FET, high BMI (BMI ≥ 23 kg/m²) was associated with an impaired live birth rate (LBR, OR: 0.89, 95% CI: 0.82-0.96, P = 0.002), but wasn't associated with the implantation rate or the clinical pregnancy rate. Subgroup analysis revealed higher LBR for women didn't complicated by polycystic ovary syndrome (PCOS, OR: 0.96, 95% CI: 0.85-1.08, P = 0.46) and women with blastocyst transferred (OR: 0.89, 95% CI: 0.68-1.16, P = 0.40). LBR did not differ between the low BMI group (BMI < 18.5 kg/m²) and the normal weight group.

CONCLUSIONS

Our study showed that high BMI in women is negatively associated with LBR in FET cycles, whereas low BMI isn't. The results of subgroup analysis implied a need for women with a high BMI to get individualized weight management and treatment. Further evidence is still required to optimize preconception health and develop Nutritional and exercise guidelines.

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.

Evaluating in vitro fertilization outcomes of patients with low body mass index following frozen-thawed embryo transfer

OBJECTIVE

To determine the relationship between patients with a low body mass index (BMI; calculated as weight in kilograms divided by the square of height in meters) and in vitro fertilization (IVF) outcomes following frozen-thawed embryo transfer (FET).

METHODS

Retrospective cohort study including 12 618 women aged 20-46 years with an underweight (<18.5) or normal weight (18.5-24.9) BMI who underwent controlled ovarian stimulation for IVF in a private and academic IVF center between August 2002 and December 2019.

RESULTS

Anti-Müllerian hormone, peak estradiol levels, number of MII oocytes, and fertilized oocytes were greater in the underweight group compared with the normal weight group. The total required gonadotropin dose was lower in the underweight patients compared with the normal weight patients. MII, fertilization, blastulation, and euploid rates did not differ before and after adjusting for confounders between BMI groups. In a cohort of 316 patients who underwent preimplantation genetic testing for aneuploidy and single euploid FET, pregnancy loss, pregnancy, clinical pregnancy, and live birth rates before and after controlling for covariates were similar between groups.

CONCLUSION

Although there are known fetal growth or obstetrical issues associated in patients with a low BMI, it is reassuring that these risks do not extend to embryologic or clinical outcomes from IVF treatment.

Reproductive and obstetric outcomes in mildly and significantly underweight women undergoing IVF

RESEARCH QUESTION

What is the impact of low body mass index (BMI) on live birth rates and obstetric outcomes in infertile women treated with IVF and fresh embryo transfer?

DESIGN

This was a retrospective cohort study of infertile patients in an academic hospital setting who underwent their first oocyte retrieval with planned autologous fresh embryo transfer between 1 January 2012 and 31 December 2018. The primary study outcome was live birth rate. Secondary outcomes were IVF treatment and delivery outcomes. Underweight patients were stratified into a significantly underweight group (body mass index [BMI] <17.5 kg/m²) and a mildly underweight group (BMI 17.5-18.49 kg/m²), and were compared with a normal-weight group (BMI 18.5-24.9 kg/m²).

RESULTS

A total of 5229 patients were included (significantly underweight, 76; mildly underweight, 231; normal weight, 4922), resulting in 4798 embryo transfers. After oocyte retrieval, there were no significant differences between groups for total oocytes, mature oocyte yield and number of supernumerary blastocysts cryopreserved. Among women who had an embryo transfer, there were no significant differences in the live birth rates in significantly (31.0%, odds ratio [OR] 0.67, confidence interval [0.95, CI] 0.40-1.13) and mildly (37.7%, OR 0.95, CI 0.73-1.33) underweight patients compared with normal-weight patients (35.9%). Additionally, there were no statistically significant increased risks of preterm delivery, Caesarean delivery or a low birthweight (<2500 g) neonate.

CONCLUSIONS

Mildly and significantly underweight infertile women have similar pregnancy and live birth rates to normal-weight patients after IVF treatment. In addition, underweight patients do not have an increased risk of preterm delivery (<37 weeks), Caesarean delivery or a low birthweight neonate.

Maternal preconception body mass index and time-to-pregnancy in Shanghai Women, China

Previous studies suggested an association between female fertility and body size, but most of these studies were from Western countries and focused mainly on obesity. This study investigated the association between preconception body mass index (BMI) and time to pregnancy (TTP) in women planning to conceive from Shanghai, China. A total of 1,182 women aged 24-46 years were recruited from the Shanghai Birth Cohort between 2013 and 2015 and were followed up for 12 months. Preconception BMI was categorized as underweight, normal weight, and overweight/obesity according to the Chinese classification of BMI. Fecundability (FOR) and infertility (IOR) odds ratios were estimated using Cox (n = 1,092) and Logistic (n = 820) regression models, respectively. We found no differences in fecundability between underweight and overweight/obese women and normal-weight women. Furthermore, underweight and overweight/obese women did not have a higher risk of infertility compared with normal-weight women. Our findings suggest that non-optimal preconception BMI does not appear to influence female fecundability and infertility in Chinese women. These results should be interpreted with caution as they may be applicable only to women with demographic and anthropometric characteristics similar to our study population. Our findings need to be confirmed in other populations.

Does an FSH surge at the time of hCG trigger improve IVF/ICSI outcomes? A randomized, double-blinded, placebo-controlled study

STUDY QUESTION

Does an artificially induced FSH surge at the time of hCG trigger improve IVF/ICSI outcomes?

SUMMARY ANSWER

An additional FSH bolus administered at the time of hCG trigger has no effect on clinical pregnancy rate, embryo quality, fertilization rate, implantation rate and live birth rate in women undergoing the long GnRH agonist (GnRHa) protocol for IVF/ICSI.

WHAT IS KNOWN ALREADY

Normal ovulation is preceded by a surge in both LH and FSH. Few randomized clinical trials have specifically investigated the role of the FSH surge. Some studies indicated that FSH given at hCG ovulation trigger boosts fertilization rate and even prevents ovarian hyperstimulation syndrome (OHSS).

STUDY DESIGN, SIZE, DURATION

This was a randomized, double-blinded, placebo-controlled trial conducted at a single IVF center, from June 2012 to November 2013. A sample size calculation indicated that 347 women per group would be adequate. A total of 732 women undergoing IVF/ICSI were randomized, using electronically randomized tables, to the intervention or placebo groups. Participants and clinical doctors were blinded to the treatment allocation.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Patients aged ≤42 years who were treated with IVF/ICSI owing to tubal factor, male factor, unexplained, endometriosis and multiple factors were enrolled in this trial. Subjects all received a standard long GnRHa protocol for IVF/ICSI and hCG 6000–10 000 IU to trigger oocyte maturation. A total of 364 and 368 patients were randomized to receive a urinary FSH (uFSH) bolus (6 ampules, 450 IU) and placebo, respectively, at the time of the hCG trigger. The primary outcome measure was clinical pregnancy rate. The secondary outcome measures were FSH level on the day of oocyte retrieval, number of oocytes retrieved, good-quality embryo rate, live birth rate and rate of OHSS.

MAIN RESULTS AND THE ROLE OF CHANCE

There were no significant differences in the baseline demographic characteristics between the two study groups. There were also no significant differences between groups in cycle characteristics, such as the mean number of stimulation days, total gonadotrophin dose and peak estradiol. The clinical pregnancy rate was 51.6% in the placebo group and 52.7% in the FSH co-trigger group, with an absolute rate difference of 1.1% (95% CI −6.1% to 8.3%). The number of oocytes retrieved was 10.47 ± 4.52 and 10.74 ± 5.01 (P = 0.44), the rate of good-quality embryos was 37% and 33.9% (P = 0.093) and the implantation rate was 35% and 36% (P = 0.7) in the placebo group and the FSH co-trigger group, respectively.

LIMITATIONS, REASONS FOR CAUTION

This was a single-center study, which may limit its effectiveness. The use of uFSH is a limitation, as this is not the same as the natural FSH. We did not collect follicular fluid for further study of molecular changes after the use of uFSH as a co-trigger.

WIDER IMPLICATIONS OF THE FINDINGS

Based on previous data and our results, an additional FSH bolus administered at the time of hCG trigger has no benefit on clinical pregnancy rates in women undergoing the long GnRHa protocol in IVF/ICSI: a single hCG trigger is sufficient.

STUDY FUNDING/COMPETING INTEREST(S)

This study was supported by the National Key Research and Development Program of China (2016YFC1000205); Sun Yat-Sen University Clinical Research 5010 Program (2016004); the Science and Technology Project of Guangdong Province (2016A020216011 and 2017A020213028); and Science Technology Research Project of Guangdong Province (S2011010004662). There are no conflicts of interest to declare.

TRIAL REGISTRATION NUMBER

The trial was registered in the Chinese Clinical Trial Registry (ChiCTR-TRC-12002246).

TRIAL REGISTRATION DATE

20 May 2012.

DATE OF FIRST PATIENT’S ENROLMENT

10 June 2012.

Body fat distribution influences ART outcomes

Body mass index (BMI) is the widely used method to evaluate obesity, but it cannot differentiate lean from fat mass neither mass distribution. Other methods have been proposed for this evaluation, as waist and hip circumferences (WC, HC) and ratio (WHR) and body fat analysis by bioimpedance (BF%), but they have not been applied to evaluate assisted reproduction (ART) outcomes. The present study aims at determining whether body composition and adipose tissue distribution are better than BMI on ART outcomes. Analysis was performed through five anthropometric measurements of 788 women submitted to controlled ovarian hyperstimulation and in vitro fertilization techniques. The increase of body fat, independently of the measurement method, was associated to worse reproductive results. However, a surprising finding was that eutrophic women with WC lower than 80 cm showed gestation rates two times superior (38.9% versus 14.3%) when compared to eutrophic women with WC larger than 80 cm (p = .002). Furthermore, obese women with WHR higher than 0.85 showed worse ART results, considering oocytes retrieved, mature oocytes and fertilization when compared to those with WHR lower than 0.85. As a conclusion, it was observed that the body fat distribution, especially WC, was more relevant than BMI to predict ART outcomes.

A propensity-matched study of the association between pre-pregnancy maternal underweight and perinatal outcomes of singletons conceived through assisted reproductive technology

RESEARCH QUESTION

Is pre-pregnancy maternal underweight associated with perinatal outcomes of singletons who were conceived through assisted reproductive technology (ART)?

DESIGN

A 10-year (2006-2015) Chinese sample of 6538 women and their singleton infants who were conceived through ART was used to examine the association between pre-pregnancy maternal underweight and perinatal outcomes. Propensity scores for underweight were calculated for each participant using multivariable logistic regression, which was used to match 740 (91.36% of 810) underweight women with 740 normal weight women; the effects of underweight on birth weight and gestational age were then assessed by generalized estimating equation model.

RESULTS

After propensity score matching, the birth weight was lower (difference -136.83 g, 95% CI -184.11 to -89.55 g) in the underweight group than in the normal weight group. The risks of low birth weight (LBW) and small for gestational age (SGA) were increased in the underweight group compared with those in the normal weight group (LBW: RR 1.64, 95% CI 1.01 to 2.67; SGA: RR 1.46, 95% CI 1.06 to 2.02). The risks of fetal macrosomia and being large for gestational age (LGA) were decreased in the underweight group compared with those in the normal weight group (macrosomia: RR 0.39, 95% CI 0.26 to 0.61; LGA: RR 0.36, 95% CI 0.24 to 0.53). The associations between underweight, gestational age and preterm birth were not statistically significant.

CONCLUSIONS

Among women undergoing ART, pre-pregnancy maternal underweight was associated with lower birth weight, increased LBW and SGA risks, and decreased fetal macrosomia and LGA risks in singleton infants.

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.

Should high BMI be a reason for IVF treatment denial?

Our aim was to examine the influence of BMI on the live-birth rate following IVF/ICSI and evaluate its specific contribution among other factors thus enabling accurate reproductive policy development. All patients that underwent IVF/ICSI at our center during January 2012-July 2015 were included in this retrospective study. A total of 1654 ICSI cycles were divided into four groups according to the patient's BMI (kg/m²): group I (normal weight): <25 (943 cycles); group II (overweight): 25-30 (403 cycles); group III (obese): 30-35 (212 cycles); group IV (morbid obesity): >35 (96 cycles). Comparing the four groups of BMI, mean age and number of previous ART cycles was significantly lower in group I compared to groups II, III and IV. Length of treatment was significantly shorter in group I compared to groups II, III and IV. Ovarian response to COH was comparable in terms of mean estradiol and progesterone levels on the day of hCG administration mean number of oocytes retrieved, fertilized and number of embryos transferred. Endometrial thickness was significantly lower in group IV. Outcome measures, such as implantation rate, clinical pregnancy rate (CPR) per cycle and per ET, as well as live-birth rates did not differ significantly between the groups, although in group IV LBR per cycle and per ET was lower. Multivariate logistic regression stepwise analysis found a significant correlation between age and BMI but did not find correlation between BMI and clinical pregnancy (p = 0.436) or LB (p = 0.206). The results of our relatively large retrospective study did not demonstrate a significant impact of BMI on the ART cycle outcome. Therefore, BMI should not be a basis for IVF treatment denial.

Low level of basal testosterone: a significant risk factor for poor oocyte yield after ovulation induction

The objective of this study was to further investigate the association of low androgen levels and poor ovarian response or negative pregnancy outcome in in vitro fertilisation treatment using a retrospective cohort study. Chinese women (n=1950) of relatively young age, with normal range of basal FSH and antral follicle count undergoing an in vitro fertilisation cycle were selected and testosterone and dehydroepiandrosterone sulfate levels were measured on Day 3 of the menstrual cycle before subsequent in vitro fertilisation treatment. The main outcome measures of the study were ovarian stimulation parameters and clinical pregnancy. Basal testosterone levels of poor responders and non-pregnant women were significantly lower than normal responders and pregnant women, respectively. Patients with low basal testosterone levels had significantly lower number of mature oocytes, cleavage-stage embryos, frozen embryos, lower fertilisation and pregnancy rates and required higher doses of gonadotrophins. Androgen levels had no correlation with early spontaneous abortion rates. Multivariable logistic analysis revealed that low basal testosterone (<0.88nmolL(-1)) was an independent risk factor for poor oocyte yield (odds ratio: 1.61; 95% confidence interval: 1.01-2.57; P=0.045). In conclusion, a low level of basal testosterone was a significant risk factor for poor oocyte yield after ovarian stimulation and might negatively influence pregnancy chances with in vitro fertilisation. Basal dehydroepiandrosterone sulfate levels were not predictive for poor ovarian response or negative pregnancy outcome in this population.

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

OBJECTIVE

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

DESIGN

Retrospective cohort study using national data and log binomial regression.

SETTING

Not applicable.

PATIENT(S)

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

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

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

RESULT(S)

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

CONCLUSION(S)

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

Systematic review and meta-analysis on the association of prepregnancy underweight and miscarriage

BACKGROUND

Maternal underweight, overweight and obesity have been associated with a higher risk of miscarriage. Most individual reports and all meta-analyses have addressed high body mass index.

OBJECTIVES

To review the literature and summarize the risk of miscarriage in underweight women vs those with normal weight.

METHODS

A Medline Search (1st January 1990-20th November 2015, human, in English, French, Italian, Spanish or Portuguese) was conducted. Both spontaneous pregnancies and pregnancies after assisted reproduction techniques were considered. Cohort and case control studies were included if they reported data on the outcome of interest (clinical miscarriage), in underweight and normal weight women. Information on clinical miscarriage in other body mass index categories was collected when available. Two investigators reviewed the abstracts, full text papers and extracted data. Review Manager 5.1 software was used to summarize the results.

RESULTS

32 studies (30 cohort, 2 case control) and a total of 265,760 women were included. In cohort studies, the relative risk (RR) of clinical miscarriage in underweight women was 1.08, 95% CI 1.05-1.11; p<0.0001). The corresponding figures were RR 1.09, 95% CI 1.04-1.13; p<0.0001 for overweight women and RR 1.21, 95% CI 1.15-1.27; p<0.00001 for obese women. In case control studies, the odds ratio (OR) of clinical miscarriage in underweight women was 1.02, 95% CI 0.46-2.30; p=0.95). The corresponding figures were OR 1.01, 95% CI 0.88-1.16; p=0.89 for overweight women and OR 1.26, 95% CI 1.01-1.57; p=0.04 for obese women. The limitations of this study are that it is restricted to studies with information on underweight women and that I² ranges from 0 to 91% in different subgroups.

CONCLUSION

We conclude that maternal underweight is associated with a slightly increased risk of clinical miscarriage, similar to that of overweight women and lower than the risk observed in obesity. The heterogeneity displayed in some subgroups limits the strength of the conclusion.

Low aneuploidy rate in early pregnancy loss abortuses from patients with polycystic ovary syndrome

A prospective cohort study was conducted to determine whether chromosome aneuploidy increases the risk of early spontaneous abortions in patients with polycystic ovary syndrome (PCOS). A total of 1461 patients who conceived after IVF and embryo transfer were followed; 100 patients who had experienced clinical spontaneous abortion were recruited, 32 with PCOS and 68 without PCOS. Before 2013, genetic analysis comprised conventional cultured villus chromosome karyotyping and a multiplex ligation-dependent probe amplification subtelomere assay combined with fluorescence in-situ hybridization; since 2013, array-based comparative genomic hybridization technique combined with chromosome karyotyping has been used. Age, BMI, pregnancy history, gestational age and total gonadotrophin dosage did not differ significantly between the PCOS and non-PCOS groups. In the PCOS group, 28.1% of abortuses demonstrated aneuploidy, which was significantly lower (P = 0.001) than in the non-PCOS group (72.1%). Further statistical analyses controlling for maternal age demonstrated that abortuses of women with PCOS were significantly less (P = 0.001) likely to have chromosome aneuploidy. Embryonic aneuploidy does not play a vital role in early spontaneous abortion in women with PCOS. Maternal factors resulting in endometrial disorders are more likely to be responsible for the increased risk of early spontaneous abortion in patients with PCOS.

The impact of lifestyle behaviors on infertility treatment outcome

PURPOSE OF REVIEW

The impact of lifestyle behaviors on fertility is poorly understood, as is the impact of specific behaviors on the advanced reproductive technologies. It is vital for healthcare professionals to understand which lifestyle behaviors can have the greatest negative impact in an effort to improve patient recommendations. The purpose of this article is to review the recent research on this topic.

RECENT FINDINGS

The majority of research in this area is epidemiological; there are a few randomized controlled trials (RCTs) regarding weight loss in infertility patients, but no RCTs on other lifestyle behaviors. High or low BMI, alcohol, vigorous exercise, nicotine, and antidepressant medications may have an adverse impact on fertility. It is unclear whether dietary supplements can have a positive impact on fertility. Patients do not appear to follow recommendations for lifestyle behavior modifications during infertility treatment.

SUMMARY

Healthcare professionals need to be more effective in making lifestyle behavior recommendations for infertility patients, including those receiving treatment.

VIDEO ABSTRACT

http://links.lww.com/COOG/A13.

Analysis of in vitro fertilization data with multiple outcomes using discrete time-to-event analysis

In vitro fertilization (IVF) is an increasingly common method of assisted reproductive technology. Because of the careful observation and follow-up required as part of the procedure, IVF studies provide an ideal opportunity to identify and assess clinical and demographic factors along with environmental exposures that may impact successful reproduction. A major challenge in analyzing data from IVF studies is handling the complexity and multiplicity of outcome, resulting from both multiple opportunities for pregnancy loss within a single IVF cycle in addition to multiple IVF cycles. To date, most evaluations of IVF studies do not make use of full data because of its complex structure. In this paper, we develop statistical methodology for analysis of IVF data with multiple cycles and possibly multiple failure types observed for each individual. We develop a general analysis framework based on a generalized linear modeling formulation that allows implementation of various types of models including shared frailty models, failure-specific frailty models, and transitional models, using standard software. We apply our methodology to data from an IVF study conducted at the Brigham and Women's Hospital, Massachusetts. We also summarize the performance of our proposed methods on the basis of a simulation study.

Impact of obesity on endometrial blood flow in women without polycystic ovarian syndrome during intracytoplasmic sperm injection

BACKGROUND

Obesity may exert a negative effect on in vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI) treatment. However, the effect of obesity on the endometrium remains unknown. This study was designed to assess the effect of isolated body mass index (BMI) on endometrial blood supply in non-polycystic ovary syndrome (PCOS) women during ICSI by power Doppler Ultrasound.

METHODS

An observational prospective study was carried out. A total of 206 patients without PCOS were divided into 4 groups based on Chinese BMI classification (kg/m(2): underweight (BMI < 18.5), normal weight (18.5 less than or equal to BMI < 24), overweight (24 less than or equal to BMI < 28), and obese (BMI greater than or equal to 28). Endometrial thickness, endometrial pattern, endometrial spiral arterial resistance index (RI) and pulsatility index (PI) values and systolic/diastolic ratio (S/D) were assessed on the day of human chorionic gonadotropin administration.

RESULTS

Obese patients required more doses of gonadotrophin and longer stimulation duration than the normal weight patients (P < 0.05). Endometrial thickness and pattern were not statistically different between the 4 BMI subgroups (P > 0.05). Subendometrial blood flow was detected in 165 (80.1%) patients and spiral arterial PI was significantly higher in the obese group than in the normal weight and underweight groups (P < 0.05). All parameters of ICSI outcome were comparable, including pregnancy and miscarriage rates.

CONCLUSIONS

Obesity (BMI greater than or equal to 28 kg/m(2)) appears to exert a negative effect on endometrial and subendometrial blood flow based on the Chinese standard of obesity; however, it seems to have no significant effect on ICSI outcomes in non-PCOS women.

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.

The impact of female obesity on the outcome of fertility treatment

The rising prevalence of obesity has had a profound impact on female reproductive health. Increased body mass index (BMI) is associated with ovulatory subfertility and anovulatory infertility. Overweight and obese women have poorer outcomes following fertility treatment. They respond poorly to clomiphene induction of ovulation and require higher doses of gonadotrophins for ovulation induction and superovulation. Ovarian stimulation for assisted reproduction produces fewer follicles resulting in the harvest of fewer oocytes. Fertilization rates are poorer and the embryo quality is impaired in younger women who are obese. Pregnancy rate in some studies is lower and there is an increased risk of early pregnancy loss. Weight loss regularizes menstrual cycles and increases the chance of spontaneous ovulation and conception in anovulatory overweight and obese women. Gradual sustained weight loss is beneficial whereas crash dieting is detrimental.