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

The Effect of BMI and Lipid Metabolism on Pregnancy Outcomes of PCOS Patients Treated with ICSI_IVF

Background and Aim

Polycystic ovary syndrome is a highly prevalent and important cause of infertility. This complication demonstrates relationships with obesity, increased androgen production, and insulin resistance. The typical pattern of dyslipidemia in women with PCOS is a decrease in high-density lipoprotein and an increase in triglycerides. On the other hand, fat people are at a higher risk of hyperandrogenism, insulin resistance, hypercholesterolemia, hypertriglyceridemia, and infertility compared to ordinary people.

Methods

In this cross-sectional study, 150 patients under 40 years suffering from PCOS based on the Rotterdam criteria, who were candidates for in vitro fertilization (IVF), were examined at Yas Hospital (Tehran, Iran) from April to September 2022. In addition to demographic information, lipid profile, body mass index, obstetric, fasting blood sugar (FBS), beta HCG (negative or positive), and ultrasound were also checked and pregnancy status was checked six weeks later.

Results

The rate of clinical and chemical pregnancy in women with a normal BMI was about two times that of women with a BMI above 25 kg/m2. In addition, the pregnancy rate in women with dyslipidemia was significantly lower than that in ordinary women. The amount of FBS was substantially lower in people with positive pregnancies.

Conclusion

The probability of pregnancy in PCOS women with a BMI is higher than normal women, and dyslipidemia is lower than that in ordinary people. Therefore, enhancing BMI and dyslipidemia in these women before starting infertility treatment is recommended.

Intra-patient analysis of individual weight gain or loss between IVF cycles: cycle now and transfer later

STUDY QUESTION

What is the impact of clinically significant weight change on outcomes related to IVF cycle performance?

SUMMARY ANSWER

While individual weight loss did not significantly impact ovarian response to stimulation or other cycle outcome parameters in our study, some positive associations were found for individual weight gain.

WHAT IS KNOWN ALREADY

The role of weight-change in patients undergoing IVF has been largely studied by comparing weight loss in different cohorts of patients stratified by a static BMI. Specifically, obesity has been extensively studied in relation to its negative effects on assisted or unassisted conception outcomes and ovulatory function. Previous research has shown conflicting results, while BMI, which is commonly used as a marker of obesity, may not accurately reflect the underlying factors affecting fertility in obese patients.

STUDY DESIGN, SIZE, DURATION

This study utilized a retrospective within-patient repeated measurement analysis design to assess the impact of weight change on IVF outcomes in cycles where all embryos were cryopreserved at the blastocyst stage for transfer at a later date.

PARTICIPANTS/MATERIALS, SETTING, METHODS

The study was conducted at an academically affiliated fertility center. The data included 961 women who underwent at least two IVF cycles between December 2014 and June 2020, with documented short-term weight gain (n = 607) or weight loss (n = 354) within 1 year from their initial IVF cycle. Multivariable generalized estimating equations (GEE) and generalized linear mixed models (GLMM) were employed to assess associations between weight change and outcomes across cycles.

MAIN RESULTS AND THE ROLE OF CHANCE

The multivariable models indicated that weight loss did not show any significant associations with the numbers of oocytes retrieved, or mature oocytes, the fertilization rate or the blastulation rate. However, weight gain demonstrated a minor positive association with the number of oocytes retrieved in both GEE models (coefficient: 0.01, 95% CI: 0.00-0.01) and GLMM models (0.01, 95% CI: 0.01-0.00). There was also a potential increase in the fertilization rate with weight gain, as indicated by a positive coefficient in both GEE models (coefficient: 0.01, 95% CI: 0.00-0.02) and GLMM models (coefficient: 0.01, 95% CI: 0.00-0.01). However, the association between weight gain and the embryo blastulation rate was not statistically significant in any model.

LIMITATIONS, REASONS FOR CAUTION

This study focused on cycle performance parameters instead of reproductive outcomes, which restricted our ability to evaluate the impact of weight change on cumulative live birth rates. Additionally, the study did not account for variables such as stimulation protocols, potentially introducing confounding factors and limiting the generalizability of the results.

WIDER IMPLICATIONS OF THE FINDINGS

Although obesity is associated with adverse obstetrical risks, there is less evidence of adverse reproductive outcomes in IVF cycles. We therefore recommend that an IVF cycle should not be delayed due to weight, so that the patient is not adversely affected by increasing age. The IVF cycle should aim to freeze all embryos, so that embryo transfer can then occur after weight loss, so as to limit the recognized obstetrical risks.

STUDY FUNDING/COMPETING INTEREST(S)

The study was not funded and there were no competing interests.

TRIAL REGISTRATION NUMBER

N/A.

Does body mass index compromise assisted reproductive technique outcomes? A cross-sectional study

Background

Overweight and obese people face several health problems. Female obesity has been shown to reduce fertility in the general population. Assisted reproductive technology outcomes in obese cases are widely studied, but the results are inconclusive.

Objective

This study aimed to compare live birth rate (LBR) among women with 4 different types of body mass index (BMI).

Materials and Methods

In this cross-sectional study, data of 1611 women, who were candidates for fresh and frozen embryo transfer cycles, was extracted from 2051 medical files at the Reproductive Sciences Institute, Yazd, Iran from May 2019-May 2021. The participants were divided into 4 groups (underweight, normal, overweight, and obese) according to their BMI, and LBR was considered to be the main outcome.

Results

Of 1611 women, 39 were underweight, 585 were normal, 676 were overweight, and 311 were obese. Underweight women had the lowest LBR (12.8%), but there was no statistically significant difference (p = 0.55). In addition, LBR was compared in the 4 BMI groups according to age, type of transfer cycle (fresh or freeze), and cause of infertility, and there was comparable LBR in the 4 BMI groups. However, metaphase 2 oocyte rate, doses of gonadotropin usage in the cycles, and estradiol level had statistically significant differences (p < 0.001).

Conclusion

According to our study, obesity does not affect LBR in the IVF cycle, regardless of fresh or frozen embryo transfer cycles, different age groups, and causes of infertility.

Elevated body mass index in modified natural cycle frozen euploid embryo transfers is not associated with live birth rate

PURPOSE

To assess the impact of elevated BMI on the success of modified natural cycle frozen embryo transfers (mNC-FET) of euploid embryos.

METHODS

This retrospective cohort study at a single academic institution reviewed mNC-FET involving single euploid blastocysts from 2016 to 2020. Comparison groups were divided by pre-pregnancy BMI (kg/m2) category: normal weight (18.5-24.9), overweight (25-29.9) or obese (≥ 30). Underweight BMI (< 18.5) was excluded from the analysis. The primary outcome was live birth rate (LBR) and secondary outcome was clinical pregnancy rate (CPR), defined as presence of fetal cardiac activity on ultrasound. Absolute standardized differences (ASD) were calculated to compare descriptive variables and p-values and multivariable logistic regressions with generalized estimating equations (GEE) were used to compare pregnancy outcomes.

RESULTS

562 mNC-FET cycles were completed in 425 patients over the study period. Overall, there were 316 transfers performed in normal weight patients, 165 in overweight patients, and 81 in obese weight patients. There was no statistically significant difference in LBR across all BMI categories (55.4% normal weight, 61.2% overweight, and 64.2% obese). There was also no difference for the secondary outcome, CPR, across all categories (58.5%, 65.5%, and 66.7%, respectively). This was confirmed in GEE analysis when adjusting for confounders.

CONCLUSION

While increased weight has commonly been implicated in poor pregnancy outcomes, the effect of BMI on the success of mNC-FET remains debated. Across five years of data from a single institution using euploid embryos in mNC-FET cycles, elevated BMI was not associated with reduced LBR or CPR.

Update on obesity and assisted reproductive technology

Background

The effect of obesity on IVF consequences is still debatable.

Main body

Obesity is linked to a greater likelihood of maternal and fetal complications all through gestation, including miscarriage, premature births, fetal demise, and adverse pregnancy outcomes. There was no increase in chromosomal abnormality percentages with increasing body mass index (BMI), implying that poor oocyte “performance” in obese patients could be caused by variables other than chromosomal expertise. Ribonucleic acid (RNA)-sequence research showed molecular changes in the oocytes of obese patients. Each 5-unit rise in female BMI is attributed with both a 5% and 7% reduction in hazard for CPR and LBR, in both, and a 9% rise in the comparative chance of miscarriage. There is no clinical or moral mandate for establishing a societal BMI limit for rejecting a client or couple direct exposure to infertility treatment. Assessment with an interdisciplinary approach prior to an IVF treatment should be done to assess the safety of oocyte retrieval under anesthesia, taking into account variables including body mass index and comorbid conditions. On LBR, there is no convincing evidence of the significance of lifestyle modification for losing weight. There is contradictory information on the impacts of weight loss surgery on pregnancy outcomes. IVF success rate was unaffected by weight loss surgery.

Conclusion

Obesity has been linked to anovulation, decreased ovarian response to ovulatory prescription medications, changed oocyte and endometrial activity, an elevated risk of fertility problems, and reduced rates of live birth following IVF.

Development and validation of a live birth prediction model for expected poor ovarian response patients during IVF/ICSI

BACKGROUND

A number of live birth predictive model during assisted reproductive technology treatment have been available in recent years, but few targeted evaluating the chances of live birth in poor ovarian response(POR) patients. The aim of this study was to develop a nomogram based on POSEIDON criteria to predict live birth in patients with expected POR.

METHODS

This retrospective cohort study using clinical data from 657 patients in POSEIDON Groups 3 and 4 (antral follicle count [AFC] ≤5 and AMH <1.2 ng/ml) in the Center for Reproductive Medicine, First Affiliated Hospital of Xinjiang Medical University, and Construction a nomogram model t.

RESULTS

Among 657 expected POR patients, 111 (16.89%) had live births, and 546 (83.11%) did not have live births. These were divided into a training set(n=438) and a validation set (n=219). Multivariate logistic regression analysis showed that the age (OR = 0.91, 95% CI: 0.86-0.97), BMI (OR = 1.98, 95% CI: 1.09-3.67), AMH (OR = 3.48, 95% CI: 1.45-8.51), normal fertilized oocytes (OR = 1.40, 95% CI: 1.21-1.63), and the basal FSH (OR = 0.89, 95% CI: 0.80-0.98) of the female were independent factors predicting live birth in patients with expected POR. Then, an individualized nomogram prediction model was built from these five factors. The area under the ROC curve of the live birth prediction model was 0.820 in the training set and 0.879 in the validation set.

CONCLUSION

We have developed a nomogram combining clinical and laboratory factors to predict the probability of live birth in patients with an expected POR during IVF/ICSI, which can helpful for clinician in decision-making. However, the data comes from the same center, needs a prospective multicenter study for further in-depth evaluation and validation of this prediction model.

The effect of obesity on human reproductive health and foetal life

Obesity in both women and men is regarded as one of the many factors that may contribute to impaired reproductive health. Obesity can be accompanied by several neuroendocrine and ovarian dysfunctions, including chronic oligo/anovulation, menstrual irregularities, subfertility, and the increased risk of pregnancy in women. Insulin resistance, elevated triglyceride and fatty acid levels, and the secretion of adipocytokines caused by the excessive accumulation of adipose tissue associated with obesity adversely affect reproductive functions. Alterations in sperm quality and motility and hormone levels related to a rise in body mass index (BMI) may predispose men to infertility. The mechanisms of action of obesity on male infertility include endocrinopathy, erectile dysfunction, epididymitis, increased leptin and adipocytes, increased aromatase, inflammatory cytokines secreted by fat tissue, and sperm DNA fragmentation. This study reports that an increased BMI may lead to low semen quality, poor sperm motility, and reduced fertilization rates in men as well as anovulation, pregnancy loss, diminished pregnancy, and low live birth rates in women. Having optimal weight with balanced nutrition enables one to maintain a continuity of reproductive health throughout the entire life cycle, which is extremely important in terms of having a healthy embryo, including pre-foetal life, in the continuity of pregnancy and having a live birth.

Impact of elevated body mass index on cumulative live birth rate and obstetric safety in women undergoing assisted reproductive technology

This study evaluated the impact of elevated body mass index (BMI) on short- and long-term outcomes of in-vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI) treatments. A total of 7229 patients undergoing IVF/ICSI fresh cycles and subsequent frozen embryo transfer cycles from 2014 to 2020 were divided into normal (18.5-24.9 kg/m²) and high BMI (≥ 25 kg/m²) groups. Ovarian response, pregnancy outcomes, and safety of both mother and fetus were the main outcome measures. Furthermore, multivariate analysis was used to determine whether BMI was associated with cumulative live birth rate (CLBR). Results showed that for younger women (< 38 year), CLBR was significantly reduced in the high BMI group compared with the normal BMI control and was accompanied by fewer retrieved oocytes and available embryos. Additionally, the incidence of hypertensive disorders of pregnancy, fetal macrosomia, and cleft lip and palate birth defects resulting from cumulative live births was significantly higher compared with the normal BMI group. No differences were observed among older women (≥ 38 year). Multivariate analysis revealed that high BMI was a risk factor for CLBR. Our study suggested that elevated BMI has a greater adverse impact on younger women.

Specific lifestyle factors and in vitro fertilization outcomes in Romanian women: a pilot study

Background

Infertility is an important health concern worldwide. Although lifestyle habits and behaviors have been widely reported as predictors of IVF outcomes by previous studies, they have not been reported for Romanian women undergoing IVF. In this regard, our pilot study aimed to begin to address the data gap by assessing lifestyle predictors of in vitro fertilization (IVF) outcomes in Romanian women.

Study design

Our pilot study included 35 participants who completed a first IVF cycle at a single infertility center. We evaluated individual self-reported lifestyle habits and behaviors as predictors of IVF outcomes, and employed principal component analysis (PCA) to characterize multiple lifestyle habits and behaviors into personal care product (PCP) use, and healthy diet and physical activity patterns as predictors of IVF outcomes.

Results

Our PCA analysis showed that greater use of PCPs was associated with lower probabilities of pregnancy (RR: 0.92, 95% CI [0.87-0.98]) and live birth (RR: 0.94, 95% CI [0.88-1.01]) while, the healthy dietary habits and physical activity were associated with a higher likelihood of pregnancy, although without statistical significance (RR: 1.10, 95% CI [0.93-1.30]).

Conclusions

In this pilot study we identified associations between IVF outcomes among Romanian women and certain lifestyle habits and behaviors including stress, diet and physical activity, and certain PCP use. We also estimated the joint effects of multiple lifestyle factors using PCA and found that PCP use, healthy dietary habits and physical activity were associated with IVF outcomes.

The Impact of the Main Negative Socio-Economic Factors on Female Fertility

The negative relationship between fertility and income is well known to economists and demographers. Developed countries have experienced a remarkable decline in their fertility rate as they have become richer. Lifestyle choices can affect a woman’s ability to conceive. Tobacco use and heavy drinking is associated with an increased risk of ovulation disorders, and being overweight or significantly underweight can inhibit normal ovulation. Our research is focused on evaluating the main risk factors that influence female fertility. We assembled a country-specific dataset on birth rate and socio-economic factors for 171 countries, using data integrated from publicly available data sources. The regression model shows that the negative factor with the greatest impact on female fertility is represented by the level of income per capita. The negative effects of smoking, alcohol consumption, and body weight on female fertility are also demonstrated, but with a lower impact compared to the average income per capita.

Embryonic Development in Relation to Maternal Obesity Does Not Affect Pregnancy Outcomes in FET Cycles

This retrospective cohort study examined the effect of maternal BMI on embryo morphokinetics using a time-lapse incubator (TLI) and evaluated the effect on outcomes of frozen embryo transfer (FET) cycles. The study included 641 women who underwent FET of a total of 2553 embryos from January 2017 to August 2019. The women were divided into four groups according to BMI: underweight (<18.5 kg/m2), normal weight (18.5−24.99 kg/m2), overweight (25.0−29.99 kg/m2), and obese (≥30 kg/m2). Embryos were transferred on day 3 or 5, and their development was monitored using a TLI. We found that oocytes from obese patients were slower in the extraction of the second polar body (tPB2) after fertilization and the two pronucleus stage appeared later compared to normal-weight women. The time to fading of the pronucleus (tPNf), t2, and t4 were comparable between the four groups. Oocytes from underweight and overweight women had significantly faster cleavage at t3 and t5−t8 compared to normal weight. We did not find any significant difference in pregnancy rate, clinical pregnancy rate, or miscarriage rate among groups. In conclusion, embryos from normal-weight patients had slower cleavage rates compared to obese patients, while embryo quality was similar between BMI groups. The cycle outcomes demonstrated comparable pregnancy rates among the BMI groups.

Elucidation of the changes occurring at the proteome level in ovaries of high-fat diet-induced obese rats

High-fat diet-induced obesity adversely affects the female reproductive system. The metabolic changes that the high-fat diet causes on the ovaries have not been elucidated. Herein, to understand the molecular and cellular mechanisms underlying the effects of long-term high-fat diet-fed, the changes in the global proteomic profile of the rat ovaries were investigated. The female rats were randomly divided into two groups based on their diets: the ones that were fed with the high-fat diet and the other ones that were fed with the control diet for 18 weeks. To identify differentially expressed proteins, the changes in ovary proteomes were investigated by two-dimensional electrophoresis coupled to matrix-assisted laser desorption/ionization-time-of-flight/time-of-flight and label-free quantification with nano-high performance liquid chromatography to tandem mass spectrometry (nHPLC-MS/MS). A total of 80 proteins were differentially regulated. The upregulated proteins were involved in responses to chemical and organic substances, cytokines, external stimuli, and lipids. These proteins were particularly associated with vesicles, microbodies, and cell surface proteins. The downregulated proteins were involved in biological processes associated with cellular respiration. Those proteins created a network consisting of proteins involved in aerobic respiration and energy generation. Our results demonstrated that the mechanisms related to energy production in the ovary tissue were particularly affected by the high-fat diet.

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.

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

Objective

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

Methods

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

Results

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

Conclusion

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

Higher preconceptional maternal body mass index is associated with faster early preimplantation embryonic development: the Rotterdam periconception cohort

BACKGROUND

Overweight and obesity affect millions of people globally, which has also serious implications for reproduction. For example, treatment outcomes after in vitro fertilisation (IVF) are worse in women with a high body mass index (BMI). However, the impact of maternal BMI on embryo quality is inconclusive. Our main aim is to study associations between preconceptional maternal BMI and morphokinetic parameters of preimplantation embryos and predicted implantation potential. In addition, associations with clinical IVF outcomes are investigated.

METHODS

From a tertiary hospital, 268 women undergoing IVF or IVF with intracytoplasmic sperm injection (ICSI) were included; 143 normal weight, 79 overweight and 46 obese women. The embryos of these women were cultured in the EmbryoScope, a time-lapse incubator. The morphokinetic parameters of preimplantation embryos and predicted implantation potential, assessed by the KIDScore algorithm were longitudinally evaluated as primary and secondary outcomes, respectively. The tertiary outcomes included clinical outcomes, i.e., fertilization, implantation and live birth rate.

RESULTS

After adjustment for patient- and treatment-related factors, we demonstrated in 938 embryos that maternal BMI is negatively associated with the moment of pronuclear appearance (β_tPNa -0.070 h (95%CI -0.139, -0.001), p = 0.048), pronuclear fading (β_tPNf -0.091 h (95%CI -0.180, -0.003), p = 0.043 and the first cell cleavage (β_t2 -0.111 h (95%CI -0.205, -0.016), p = 0.022). Maternal BMI was not significantly associated with the KIDScore and tertiary clinical treatment outcomes. In embryos from couples with female or combined factor subfertility, the impact of maternal BMI was even larger (β_tPNf -0.170 h (95%CI -0.293, -0.047), p = 0.007; β_t2 -0.199 h (95%CI -0.330, -0.067), p = 0.003). Additionally, a detrimental impact of BMI per point increase was observed on the KIDScore (β -0.073 (se 0.028), p = 0.010).

CONCLUSIONS

Higher maternal BMI is associated with faster early preimplantation development. In couples with female or combined factor subfertility, a higher BMI is associated with a lower implantation potential as predicted by the KIDScore. Likely due to power issues, we did not observe an impact on clinical treatment outcomes. However, an effect of faster preimplantation development on post-implantation development is conceivable, especially since the impact of maternal BMI on pregnancy outcomes has been widely demonstrated.

A non-linear dose-response relation of female body mass index and in vitro fertilization outcomes

PURPOSE

Obesity, measured by body mass index (BMI), is implicated in adverse pregnancy outcomes for women seeking in vitro fertilization (IVF) care. However, the shape of the dose-response relationship between BMI and IVF outcomes remains unclear.

METHODS

We therefore conducted a dose-response meta-analysis using a random effects model to estimate summary relative risk (RR) for clinical pregnancy (CPR), live birth (LBR), and miscarriage risk (MR) after IVF.

RESULTS

A total of 18 cohort-based studies involving 975,889 cycles were included. For each 5-unit increase in BMI, the summary RR was 0.95 (95% CI: 0.94-0.97) for CPR, 0.93 (95% CI: 0.92-0.95) for LBR, and 1.09 (95% CI: 1.05-1.12) for MR. There was evidence of a non-linear association between BMI and CPR (Pnon-linearity < 10-5) with CPR decreasing sharply among obese women (BMI > 30). Non-linear dose-response meta-analysis showed a relatively flat curve over a broad range of BMI from 16 to 30 for LBR (Pnon-linearity = 0.0009). In addition, we observed a J-shaped association between BMI and MR (Pnon-linearity = 0.006) with the lowest miscarriage risk observed with a BMI of 22-25.

CONCLUSIONS

In conclusion, obesity contributed to increased risk of adverse IVF outcomes in a non-linear dose-response manner. More prospective trials in evaluating the effect of body weight control are necessary.

A Predictive Model of Live Birth Based on Obesity and Metabolic Parameters in Patients With PCOS Undergoing Frozen-Thawed Embryo Transfer

AIMS

To determine the clinical predictors of live birth in women with polycystic ovary syndrome (PCOS) undergoing frozen-thawed embryo transfer (F-ET), and to determine whether these parameters can be used to develop a clinical nomogram model capable of predicting live birth outcomes for these women.

METHODS

In total, 1158 PCOS patients that were clinically pregnant following F-ET treatment were retrospectively enrolled in this study and randomly divided into the training cohort (n = 928) and the validation cohort (n = 230) at an 8:2 ratio. Relevant risk factors were selected via a logistic regression analysis approach based on the data from patients in the training cohort, and odds ratios (ORs) were calculated. A nomogram was constructed based on relevant risk factors, and its performance was assessed based on its calibration and discriminative ability.

RESULTS

In total, 20 variables were analyzed in the present study, of which five were found to be independently associated with the odds of live birth in univariate and multivariate logistic regression analyses, including advanced age, obesity, total cholesterol (TC), triglycerides (TG), and insulin resistance (IR). Having advanced age (OR:0.499, 95% confidence interval [CI]: 0.257 - 967), being obese (OR:0.506, 95% CI: 0.306 - 0.837), having higher TC levels (OR: 0.528, 95% CI: 0.423 - 0.660), having higher TG levels (OR: 0.585, 95% CI: 0.465 - 737), and exhibiting IR (OR:0.611, 95% CI: 0.416 - 0.896) were all independently associated with a reduced chance of achieving a live birth. A predictive nomogram incorporating these five variables was found to be well-calibrated and to exhibit good discriminatory capabilities, with an area under the curve (AUC) for the training group of 0.750 (95% CI, 0.709 - 0.788). In the independent validation cohort, this model also exhibited satisfactory goodness-of-fit and discriminative capabilities, with an AUC of 0.708 (95% CI, 0.615 - 0.781).

CONCLUSIONS

The nomogram developed in this study may be of value as a tool for predicting the odds of live birth for PCOS patients undergoing F-ET, and has the potential to improve the efficiency of pre-transfer management.

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

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

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

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

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

Background

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

Methods

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

Results

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

Conclusion

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

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.

Maternal and Fetal Risk Associated With Assisted Reproductive Technology

Infertility is a disease that affects up to 15.5% of reproductive-aged couples. Until the birth of the first neonate born from in vitro fertilization (IVF) in 1978, many infertile couples did not have an opportunity to conceive a biological child. Over the past 40 years, access to and effectiveness of IVF have increased; currently 1.7% of births in the United States result from IVF. As with any medical intervention, potential risk exists. In the case of IVF, both maternal risks (ovarian stimulation, oocyte retrieval, and subsequent pregnancy) and fetal risks that vary based on maternal age and fetal number must be considered. Importantly, risk quantification varies by comparison group, which is typically either spontaneous conception in a fertile couple or assisted non-IVF conception in an infertile couple. It must also be considered compared with the alternative of not undergoing IVF, which may mean not having a biological child. Although increased compared with spontaneous conception, absolute maternal-fetal-assisted reproductive technology risks are low and can be minimized by optimizing ovarian stimulation and transferring a single embryo. In this article, we aim to summarize maternal and fetal risk associated with use of assisted reproductive technology. The review focuses on ovarian stimulation and procedural risks as well as adverse perinatal outcomes among resultant singleton and twin pregnancies in young women and women of advanced maternal age.

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

CONTEXT

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

OBJECTIVE

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

DESIGN

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

PATIENTS

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

MAIN OUTCOME MEASURES

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

RESULTS

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

CONCLUSIONS

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

Maternal body mass index affects embryo morphokinetics: a time-lapse study

PURPOSE

To assess the effect of body mass index (BMI) on morphokinetic parameters of human embryos evaluated with time-lapse technology during in vitro culture.

METHODS

A retrospective analysis of ART cycles utilizing time-lapse technology was undertaken to assess the potential impact of maternal BMI on morphokinetic and static morphological parameters of embryo development. The cohort of patients was divided into four groups: 593 embryos from 128 underweight women in group A; 5248 embryos from 1107 normal weight women in group B; 1053 embryos from 226 overweight women in group C; and 286 embryos from 67 obese women in group D.

RESULTS

After adjusting for maternal age, paternal age, and cause of infertility, time to reach five blastomeres (t5) and time to reach eight blastomeres (t8) were longer in obese women compared with normoweight women [50.84 h (46.31-55.29) vs. 49.24 h (45.69-53.22) and 57.89 h (51.60-65.94) vs. 55.66 h (50.89-62.89), adjusted p < 0.05 and adjusted p < 0.01, respectively]. In addition, t8 was also delayed in overweight compared with normoweight women [56.72 h (51.83-63.92) vs. 55.66 h (50.89-62.89), adjusted p < 0.01]. No significant differences were observed among groups with regard to embryo morphology and pregnancy rate. Miscarriage rate was higher in underweight compared with normoweight women (OR = 2.1; 95% CI 1.12-3.95, adjusted p < 0.05).

CONCLUSION

Assessment with time-lapse technology but not by classical static morphology evidences that maternal BMI affects embryo development. Maternal obesity and overweight are associated with slower embryo development.

Body mass index restrictions in fertility treatment: a national survey of OB/GYN subspecialists

PURPOSE

To explore the attitudes of reproductive endocrinology and infertility (REI) and maternal-fetal medicine (MFM) subspecialists regarding the necessity and appropriateness of body mass index (BMI) cutoffs for women seeking fertility treatment.

METHODS

Members of the Society for Reproductive Endocrinology and Infertility (SREI) and the Society for Maternal Fetal Medicine (SMFM) were invited to participate in a survey querying their knowledge of existing institutional or clinic BMI policies and personal opinions regarding upper and lower BMI cutoffs for a range of fertility treatments, including oral ovulation agents, gonadotropins, and in vitro fertilization.

RESULTS

Respondents included 398 MFMs and 201 REIs. The majority of REI and MFM providers agreed with upper limit BMI cutoffs (72.5% vs 68.2%, p = 0.29), but REIs were twice as likely to support lower limit BMI restrictions compared to MFMs (56.2% vs 28.4%, p < 0.0001). Those who supported upper BMI restrictions were more likely to be female and report existing institutional BMI cutoffs. The majority of respondents (99.3%) believed that an official statement to guide clinicians should be issued by a national professional organization.

CONCLUSIONS

Although practice patterns widely vary, the majority of REIs and MFMs believe that there should be a BMI cutoff above which women should not be offered immediate fertility treatment. Furthermore, there is a reported need for a written statement by a national professional organization to guide clinical practice and to ensure that OB/GYN subspecialists are providing consistent, fair, and safe recommendations to infertile women at the extremes of BMI.

Effects of maternal body mass index on pregnancy outcome after 8570 artificial insemination cycles with donor's sperm

Increased body mass index (BMI) might have an adverse effect on pregnancy. However, the influence of BMI on the pregnancy outcomes after artificial insemination with donor's sperm (AID) had been rarely reported. This study aimed to investigate the correlation between BMI and AID. The pregnancy outcome of 8570 AID cycles was retrospectively analyzed. BMI was categorized as underweight (<18.5 kg/m²; group A), normal weight (18.5-23.9 kg/m²; group B), overweight (24-27.9 kg/m²; group C), and obese (≥28 kg/m²; group D). The results showed that cumulative pregnancy rate and cumulative live birth rate in groups A, B, C and D tended to decrease as BMI increased; however, abortion rate, and ectopic pregnancy rate in groups A, B, C, and D exhibited a gradual increase in the tendency. Cesarean delivery rate also increased as BMI increased. Birth defect rate in the group D were significantly higher than that in the group A. Interestingly, the pregnancy rate was gradually decreased with increasing age in groups A, B, and C, but this was not observed in the group D. The findings suggested that BMI can affect the pregnancy outcomes after AID; it is important to achieve a normal BMI prior to AID treatments.

Obesity and recurrent miscarriage: A systematic review and meta-analysis

The aim of this study is to perform a systematic review and meta-analysis on the relationship between excess weight and risk of recurrent pregnancy loss (RPL) and to highlight the common immunological mechanisms of these two conditions. The PubMed and MEDLINE databases were searched for publications in English available as of November 2017. The search terms used were 'recurrent pregnancy loss', 'body mass index' (BMI), 'overweight' and 'obesity'. For calculation of the odds ratio (OR) and 95% confidence intervals (CI) for miscarriage in different BMI groups, RevMan software was used (Review Manager, Version 5.3.5 for Windows; The Cochrane Collaboration). In total, 100 publications including the search terms were identified. Six studies were included for qualitative analysis, and two studies were included for quantitative analysis (meta-analysis). The association between excess weight and RPL was significant (OR, 1.34; 95% CI, 1.05-1.70; P = 0.02). The isolated analyses of the groups of obese and overweight women revealed an association only between obesity and RPL (OR, 1.75; 95% CI, 1.24-2.47; P = 0.001). The data available in the current literature revealed that obese women with a history of RPL have a high risk of future pregnancy losses, a risk which was not found among overweight women.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

The role of female obesity on in vitro fertilization outcomes

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

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.

Neutral effect of body mass index on implantation rate after frozen-thawed blastocyst transfer

OBJECTIVE

To examine the effects of body mass index (BMI) on implantation rate after uniform protocol frozen-thawed blastocyst transfer in women with a homogenous uterine environment.

DESIGN

Retrospective cohort study.

SETTING

Single IVF clinic at a large academic institution.

PATIENT(S)

Four hundred sixty-one infertile women treated at a large academic institution from January 2007 to January 2014.

INTERVENTION(S)

All women underwent standardized slow frozen-thawed blastocyst transfers with good-quality day 5-6 embryos, following an identical hormonal uterine preparation, with comparison groups divided according to BMI category: underweight (<18.5 kg/m²), normal weight (18.5-24.9 kg/m²), overweight (25.0-29.9 kg/m²), and obese (≥30.0 kg/m²).

MAIN OUTCOME MEASURE(S)

Implantation rate.

RESULT(S)

There were no statistically significant differences identified when comparing implantation rates among the four BMI cohorts. The implantation rate was 38.2% in normal weight patients, 41.7% in underweight patients, 45.1% in overweight patients, and 34.7% in obese patients. Adjusted odds ratios (OR) demonstrated no association between the main outcome, implantation rate, and BMI. Compared with the normal weight patients, the adjusted OR of implantation was 1.70 (95% confidence interval [CI], 0.40-7.72) for underweight patients, 1.61 (95% CI, 0.97-2.68) for overweight patients, and 0.92 (95% CI, 0.49-1.72) for obese patients. Secondary outcomes, including rates of miscarriage, clinical pregnancy, ongoing pregnancy, and live birth, were not significantly different between cohorts. While powered to detect a 16% difference between overweight and normal weight women, the study was underpowered to detect differences in the underweight and obese women, and no definitive conclusions can be drawn for these small cohorts. Patients with transfers that required the longest amount of time, greater than 200 seconds, had the highest average BMI of 27.5 kg/m².

CONCLUSION(S)

Under highly controlled circumstances across 7 years of data from a single institution, using a uniform uterine preparation, following a precise transfer technique with high-quality day 5-6 slow frozen-thawed blastocysts, a BMI in the overweight range of 25-29.9 kg/m² is not associated with a poorer implantation rate or live-birth rate, nor is it associated with an increased risk of miscarriage when compared with a normal BMI range. The increased length of time required during transfer for women with higher BMI suggests body habitus may contribute to difficult transfers, although this may not translate into poorer implantation rates. By using a standardized protocol for slow freezing and thawing of embryos, using identical hormonal preparation and a uniform ET protocol, a homogenous uterine environment was created in this carefully selected cohort of women, thereby minimizing confounders and uniquely highlighting the neutral effect of overweight BMI on implantation rate.

The adverse effect of overweight in assisted reproduction treatment outcomes

OBJECTIVE

To assess Body Mass Index (BMI) effects on the results obtained from ICSI cycles.

METHODS

We studied 266 ICSI cycles performed between January 2014 and December 2016. The patients were grouped according to their BMI in: Normal (18.5-24.9), Overweight (25.0-29.9) and Obese (>30). We compared the following variables between the groups: number of antral follicles, ovarian stimulation length, gonadotropin dose used, maximum estradiol level, follicles developed/antral follicles, retrieved oocytes/developed follicles and mature/retrieved oocytes, normal fertilization rate, embryo achieved/normal fertilized oocytes, clinical pregnancy and implantation rates. We used the Kruskal-Wallis and the Chi square tests. p<0.05 was considered significant.

RESULTS

Normal, Overweight and Obese patients presented comparable values for number of antral follicles (11.6±5.4, 12.5±5.5, 12.2±5.7), ovarian stimulation length (7.5±1.4, 7.6±1.1, 7.8±1.3) and gonadotropin dose used (2043±489, 1940±536, 2109±605). Obese patients had lower values of estradiol (1560±610, 1511±635, 1190±466; p=0.018), developed follicles (81%, 76%, 70%; p<0.0001), and retrieved oocytes (91%, 90%, 84%; p=0.0017); and not significantly lower values of mature oocytes (82%, 82%, 77%; p=0.26). The groups had comparable fertilization rates (72%, 73%, 69%) and embryo achieved rates (67%, 63%, 72%). The normal group had higher, but not significantly higher pregnancy and implantation rates (43%, 40%, 38%, p=0.53; and 33%, 26%, 23%; p=0.11), and significantly higher ongoing pregnancy rates (37%, 33%, 33%, p=0.042).

CONCLUSION

Increased BMI patients had impaired ovarian response and lower pregnancy rates in ICSI cycles.

Pregnancy and birth outcomes in couples with infertility with and without assisted reproductive technology: with an emphasis on US population-based studies

Infertility, defined as the inability to conceive within 1 year of unprotected intercourse, affects an estimated 80 million individuals worldwide, or 10-15% of couples of reproductive age. Assisted reproductive technology includes all infertility treatments to achieve conception; in vitro fertilization is the process by which an oocyte is fertilized by semen outside the body; non-in vitro fertilization assisted reproductive technology treatments include ovulation induction, artificial insemination, and intrauterine insemination. Use of assisted reproductive technology has risen steadily in the United States during the past 2 decades due to several reasons, including childbearing at older maternal ages and increasing insurance coverage. The number of in vitro fertilization cycles in the United States has nearly doubled from 2000 through 2013 and currently 1.7% of all live births in the United States are the result of this technology. Since the birth of the first child from in vitro fertilization >35 years ago, >5 million babies have been born from in vitro fertilization, half within the past 6 years. It is estimated that 1% of singletons, 19% of twins, and 25% of triplet or higher multiples are due to in vitro fertilization, and 4%, 21%, and 52%, respectively, are due to non-in vitro fertilization assisted reproductive technology. Higher plurality at birth results in a >10-fold increase in the risks for prematurity and low birthweight in twins vs singletons (adjusted odds ratio, 11.84; 95% confidence interval, 10.56-13.27 and adjusted odds ratio, 10.68; 95% confidence interval, 9.45-12.08, respectively). The use of donor oocytes is associated with increased risks for pregnancy-induced hypertension (adjusted odds ratio, 1.43; 95% confidence interval, 1.14-1.78) and prematurity (adjusted odds ratio, 1.43; 95% confidence interval, 1.11-1.83). The use of thawed embryos is associated with higher risks for pregnancy-induced hypertension (adjusted odds ratio, 1.30; 95% confidence interval, 1.08-1.57) and large-for-gestation birthweight (adjusted odds ratio, 1.74; 95% confidence interval, 1.45-2.08). Among singletons, in vitro fertilization is associated with increased risk of severe maternal morbidity compared with fertile deliveries (vaginal: adjusted odds ratio, 2.27; 95% confidence interval, 1.78-2.88; cesarean: adjusted odds ratio, 1.67; 95% confidence interval, 1.40-1.98, respectively) and subfertile deliveries (vaginal: adjusted odds ratio, 1.97; 95% confidence interval, 1.30-3.00; cesarean: adjusted odds ratio, 1.75; 95% confidence interval, 1.30-2.35, respectively). Among twins, cesarean in vitro fertilization deliveries have significantly greater severe maternal morbidity compared to cesarean fertile deliveries (adjusted odds ratio, 1.48; 95% confidence interval, 1.14-1.93). Subfertility, with or without in vitro fertilization or non-in vitro fertilization infertility treatments to achieve a pregnancy, is associated with increased risks of adverse maternal and perinatal outcomes. The major risk from in vitro fertilization treatments of multiple births (and the associated excess of perinatal morbidity) has been reduced over time, with fewer and better-quality embryos being transferred.

Obesity, energy balance and spermatogenesis

Obesity has grown to pandemic proportions. It affects an increasing number of children, adolescents and young adults exposed to the silent comorbidities of this disorder for a longer period. Infertility has arisen as one important comorbidity associated with the energy dysfunction promoted by obesity. Spermatogenesis is a highly regulated process that is determined by specific energetic requirements. The reproductive potential of males relies on hormonal-dependent and -independent stimuli that control sperm quality. There are conflicting data concerning the impact of male overweight and obesity on sperm quality, as well as on the possible paternal-induced epigenetic trait inheritance of obesity. In addition, it remains a matter of debate whether massive weight loss induced by lifestyle interventions, drugs or bariatric surgery may or may not benefit obese men seeking fatherhood. Herein, we propose to discuss how energy balance may modulate hormonal signalling and sperm quality in overweight and obese men. We also discuss some molecular mechanisms that mediate obesity-related dysfunction in male reproductive system and how paternal obesity may lead to trait inheritance. Finally, we will discuss how lifestyle modifications and sustained weight loss, particularly the loss achieved by bariatric surgery, may revert some of the deleterious effects of obesity in men and their offspring.