Pregnancy outcomes decline with increasing recipient body mass index: an analysis of 22,317 fresh donor/recipient cycles from the 2008–2010 Society for Assisted Reproductive Technology Clinic Outcome Reporting System registry

Mild obesity does not affect perinatal outcome in gestational carrier cycles

STUDY QUESTION

Does BMI of gestational carriers (GCs) affect perinatal outcomes after embryo transfer?

SUMMARY ANSWER

Overweight and class I obesity in GCs does not affect the rate of good perinatal outcomes.

WHAT IS KNOWN ALREADY

The use of GCs is increasing, but uniform guidance regarding optimal BMI for GCs is lacking. Women with obesity who conceive without fertility treatment or through autologous or donor in vitro fertilization are at higher risk of adverse maternal and fetal outcomes, but data on obesity in GCs are very limited.

STUDY DESIGN, SIZE, DURATION

We performed a retrospective cohort study of 1121 GC cycles from January 2015 to December 2020 at US Fertility, the largest national partnership of fertility practices in the USA.

PARTICIPANTS/MATERIALS, SETTING, AND METHODS

All GC cycles performed at a large network of fertility practices were reviewed. Same-sex partners undergoing co-IVF were excluded. The primary outcome was good perinatal outcome from the first embryo transfer, defined as a singleton live birth at ≥37 weeks of gestation with birth weight between 2500 and 4000 g. Secondary outcome measures included frequencies of live birth, clinical pregnancy, miscarriage, full-term birth, low birth weight, large for gestational age, and cesarean delivery. A generalized linear model (log-binomial) was used for each to compare outcomes across BMI groups using normal BMI (20-24.9 kg/m2) as the reference group. Risk ratios and 95% CIs were estimated for each category group relative to normal BMI.

MAIN RESULTS AND THE ROLE OF CHANCE

We identified 1121 cycles in which GCs underwent first embryo transfer, of which 263 (23.5%) were in GCs with BMI >30. Demographics and reproductive history for GCs did not differ by BMI groups. The age of intended parents, use of frozen eggs, and fresh embryo transfers were higher with increasing BMI group. There were no statistically significant associations between BMI and good perinatal outcomes, live birth, clinical pregnancy, biochemical, spontaneous abortion, or low birth weight. However, among live births, higher BMI was significantly associated with birth by cesarean (P = 0.015) and large for gestational age infants (P = 0.023).

LIMITATIONS, REASONS FOR CAUTION

This was a retrospective study, and there may be unmeasured confounders. The number of patients with BMI <20 or ≥35 was small, limiting the power for these groups. We were not able to assess all maternal and fetal outcomes.

WIDER IMPLICATIONS OF THE FINDINGS

In this study, we did not identify any significant impact of BMI on the chances of having a good perinatal outcome. Prior research studies have been inconsistent and this is the largest study to date.

STUDY FUNDING/COMPETING INTEREST(S)

No external funding was received for this work. The authors do not have any conflicts of interest to declare.

TRIAL REGISTRATION NUMBER

N/A.

Association between body mass index and in vitro fertilization/intra-cytoplasmic sperm injection outcomes: An analysis of 15,124 normal ovarian responders in China

BACKGROUND

High body mass index (BMI) results in decreased fecundity, and women with high BMI have reduced rates of clinical pregnancy and live birth in in vitro fertilization/intra-cytoplasmic sperm injection (IVF/ICSI). Meanwhile, ovarian responses show great heterogeneity in patients with a high BMI. This study aimed to analyze the effects of a high BMI on IVF/ICSI outcomes in the Chinese female with normal ovarian response.

METHODS

We performed a retrospective cohort study comprising 15,124 patients from the medical record system of the Reproductive Center of Peking University Third Hospital, with 3530 (23.3%) in the overweight group and 1380 (9.1%) in the obese group, who had a normal ovarian response (5-15 oocytes retrieved) and underwent fresh embryo transfer (ET) cycles from January 2017 to December 2018, followed by linked frozen-thawed embryo transfer (FET) cycles from January 2017 to December 2020. Cumulative live birth rate (CLBR) was used as the primary outcome. Furthermore, a generalized additive model was applied to visually illustrate the curvilinear relationship between BMI and the outcomes. We used a decision tree to identify the specific population where high BMI had the greatest effect on IVF/ICSI outcomes.

RESULTS

High BMI was associated with poor IVF/ICSI outcomes, both in cumulative cycles and in separate fresh ET or FET cycles. In cumulative cycles, compared with the normal weight group, obesity was correlated with a lower positive pregnancy test rate (adjusted odds ratio [aOR]: 0.809, 95% confidence interval [CI]: 0.682-0.960), lower clinical pregnancy rate (aOR: 0.766, 95% CI: 0.646-0.907), lower live birth rate (aOR: 0.706, 95% CI: 0.595-0.838), higher cesarean section rate (aOR: 2.066, 95% CI: 1.533-2.785), and higher rate of large for gestational age (aOR: 2.273, 95% CI: 1.547-3.341). In the generalized additive model, we found that CLBR declined with increasing BMI, with 24 kg/m 2 as an inflection point. In the decision tree, BMI only made a difference in the population aged ≤34.5 years, with anti-Mullerian hormone >1.395 ng/mL, and the first time for IVF.

CONCLUSIONS

High BMI was related to poor IVF/ICSI outcomes in women with a normal ovarian response, and CLBR declined with increasing BMI, partly due to suppressed endometrial receptivity. A high BMI had the most negative effect on young women with anticipated positive prognoses.

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

BACKGROUND

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

METHODS

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

INTERVENTIONS

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

CONCLUSIONS

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

Obesity in prenatal medicine: a game changer?

Obesity is recognized by the World Health Organization (WHO) as a disease in its own right. Moreover, obesity is an increasingly concerning public health issue across the world and its prevalence is rising amongst women of reproductive age. The fertility of over-weight and obese women is reduced and they experience a higher rate of miscarriage. In pregnant women obesity not only increases the risk of antenatal complications, such as preeclampsia and gestational diabetes, but also fetal abnormalities, and consequently the overall feto-maternal mortality. Ultrasound is one of the most valuable methods to predict and evaluate pregnancy complications. However, in overweight and obese pregnant women, the ultrasound examination is met with several challenges, mainly due to an impaired acoustic window. Overall obesity in pregnancy poses special challenges and constraints to the antenatal care and increases the rate of pregnancy complications, as well as complications later in life for the mother and child.

Association between oocyte donors' or recipients' body mass index and clinical outcomes after first single blastocyst transfers-the uterus is the most affected

OBJECTIVE

To assess whether high body mass index (BMI) in either oocyte donors or recipients is associated with poorer outcomes after the first single blastocyst transfer.

DESIGN

Retrospective study including 1,394 first blastocyst single embryo transfers (SETs) conducted by 1,394 recipients during oocyte donation cycles with the gametes retrieved from 1,394 women (January 2019-July 2021). Four BMI clusters were defined for both donors and recipients (underweight: <18.5 kg; normal weight: 18.5-24.9 kg; overweight: 25-29.9 kg; and obese: ≥30 kg).

SETTING

Network of private IVF centers.

PATIENTS

A total of 1,394 recipients aged 42.4 ± 4.0 and with a BMI of 23.2 ± 3.8 kg/m2, and 1,394 donors aged 26.1 ± 4.2 and with a BMI of 21.9 ± 2.5 kg/m2.

INTERVENTION

All oocytes were vitrified at 2 egg banks and warmed at 8 in vitro fertilization clinics that were part of the same network. Intracytoplasmic sperm injection, blastocyst culture, and either fresh or vitrified-warmed SETs were conducted. Putative confounders were investigated, and the data were adjusted through regression analyses.

MAIN OUTCOME MEASURES

The primary outcome was the live birth rate (LBR) per SET according to donors' and/or recipients' BMI. The main secondary outcome was the miscarriage rate (<22 gestational weeks) per clinical pregnancy.

RESULTS

The LBR per blastocyst SET showed no significant association with donors' BMI. Regarding recipients' BMI, instead, the multivariate odds ratio was significant in obese vs. normal-weight recipients (0.58, 95% confidence interval, 0.37-0.91). The miscarriage rate per clinical pregnancy was also significantly associated with recipients' obesity, with a multivariate odds ratio of 2.31 (95% confidence interval, 1.18-4.51) vs. normal-weight patients. A generalized additive model method was used to represent the relationship between predicted LBR or miscarriage rates and donors' or recipients' BMI; it pictured a scenario where the former outcome moderately but continuously decreases with increasing recipients' BMI to then sharply decline in the BMI range of 25-35 kg/m2. The miscarriage rate, instead, increases almost linearly with respect to both donors' and recipients' increasing BMI.

CONCLUSION

Obesity mostly affects the uterus, especially because of higher miscarriage rates. Yet, poorer outcomes can be appreciated already with a BMI of 25 kg/m2 in both oocyte donors and recipients. Finer markers of nutritional homeostasis are therefore desirable; recipients should be counseled about poorer expected outcomes in cases of overweight and obesity; and oocyte banks should avoid assigning oocytes from overweight donors to overweight and obese recipients.

The impact of increasing body mass index on in vitro fertilization treatment, obstetrical, and neonatal outcomes

BACKGROUND

Citing the risks of administering anesthesia to patients with obesity, few fertility centers offer in vitro fertilization as a treatment modality for patients with body mass indexes ≥40 kg/m2. Although previous studies have assessed clinical pregnancy and cumulative live birth rates in patients who spontaneously conceive with body mass indexes ≥50 kg/m2, there is a paucity of in vitro fertilization, obstetrical, and neonatal outcome data in patients with severe obesity who conceive after in vitro fertilization.

OBJECTIVE

This study aimed to evaluate the impact of increasing body mass index on in vitro fertilization, obstetrical, and neonatal outcomes in patients with obesity undergoing in vitro fertilization.

STUDY DESIGN

This was a retrospective cohort study within an academic fertility center including 2069 fresh in vitro fertilization/intracytoplasmic sperm injection and frozen embryo transfer cycles from January 1, 2012 to April 30, 2020; this cohort was used to determine in vitro fertilization treatment outcomes. A second embedded cohort of 867 fresh in vitro fertilization/intracytoplasmic sperm injection and frozen embryo transfer cycles that resulted in ongoing clinical pregnancies and deliveries within a single tertiary hospital system was used to determine pregnancy, maternal, and neonatal outcomes. All patients with a body mass index ≥40 kg/m2 underwent consultation with a maternal-fetal medicine specialist before starting treatment and a preoperative evaluation with an anesthesiologist before oocyte retrieval. Cycles were grouped by body mass index at cycle start (30-34.9, 35-39.9, 40-44.9, 45-49.9, and ≥50 kg/m2). Log-binomial regression and Poisson regression with an offset were fitted with body mass index of 30 to 34.9 kg/m2 as the reference group, adjusting for potential confounders including oocyte age, patient age, embryo quality, transfer type, and coexisting comorbidities. The primary outcome was live birth rate. Secondary outcomes included fertilization rate, blastulation rate, miscarriage rate, incidence of preeclampsia with severe features, gestational diabetes, labor induction, cesarean delivery, preterm delivery, and birthweight.

RESULTS

There were 2069 fresh in vitro fertilization/intracytoplasmic sperm injection and frozen embryo transfer cycle starts from January 1, 2012 to April 30, 2020. Of these, 1008 cycles were in the 30 to 34.9 kg/m2 group, 547 in the 35 to 39.9 kg/m2 group, 277 in the 40 to 44.9 kg/m2 group, 161 in the 45 to 49.9 kg/m2 group, and 76 in the ≥50 kg/m2 body mass index group. Live birth rate was not significantly different between groups. The body mass index ≥50 kg/m2 group was significantly more likely to experience preeclampsia with severe features when compared with the 30 to 34.9 kg/m2 body mass index group (absolute risk reduction, 2.75; 95% confidence interval, 1.13-6.67). Fertilization rate, blastulation rate, miscarriage rate, incidence of gestational diabetes, labor induction, cesarean delivery, preterm delivery, and neonatal birthweights were not significantly different between groups.

CONCLUSION

Among patients with body mass indexes from 30 to 60 kg/m2 who conceived via in vitro fertilization and received comprehensive prenatal care at a tertiary care hospital, in vitro fertilization, obstetrical, and neonatal outcomes were largely comparable. These data support a collaborative care approach with maternal-fetal medicine specialists and skilled anesthesiologists, reinforcing the notion that in vitro fertilization should not be withheld as a treatment modality from patients with obesity.

Higher live birth rates are associated with a normal body mass index in preimplantation genetic testing for aneuploidy frozen embryo transfer cycles: a Society for Assisted Reproductive Technology Clinic Outcome Reporting System study

OBJECTIVE

To determine whether body mass index (BMI) was associated with live birth in patients undergoing transfer of frozen-thawed preimplantation genetic testing for aneuploidy (PGT-A) embryos.

DESIGN

Retrospective cohort study of cycles reported to the Society for Assisted Reproductive Technology Clinic Outcome Reporting System.

SUBJECTS

All autologous and donor recipient PGT-A-tested cycles reported to the Society for Assisted Reproductive Technology Clinic Outcome Reporting System from 2014 to 2017.

INTERVENTION(S)

Body mass index.

MAIN OUTCOME MEASURE(S)

The primary outcome measure was the live birth rate, and the secondary outcome measures were the clinical pregnancy and biochemical pregnancy rates. Multivariable generalized additive mixed models and log-binomial models were used to model the relationship between BMI and outcome measures.

RESULT(S)

A total of 77,018 PGT-A cycles from 55,888 patients were analyzed. Of these cycles, 70,752 were autologous, and 6,266 were donor recipient. In autologous cycles, a statistically significant and clear nonlinear relationship was observed between the BMI and live birth rates, with the highest birth rates observed for the BMI range of 23-24.99 kg/m2. When using 23-24.99 kg/m2 as the referent, other BMI ranges demonstrated a lower probability of live birth and clinical pregnancy that continued to decrease as the BMI moved further from the reference value. Patients with a BMI of <18.5 kg/m2 had a 11% lower probability of live birth, whereas those with a BMI of ≥40 kg/m2 had a 27% lower probability than the referent.

CONCLUSION(S)

A normal-weight BMI range of 23-24.99 kg/m2 was associated with the highest probability of clinical pregnancy and live birth after a frozen-thawed PGT-A-tested blastocyst transfer in both autologous and donor recipient cycles. A BMI outside the range of 23-24.99 kg/m2 is likely associated with a malfunction in the implantation process, which is presumed to be related to a uterine factor and not an oocyte factor, as both autologous and donor recipient cycle outcomes were associated similarly with the BMI of the intended parent.

Frozen embryo transfer outcomes decline with increasing female body mass index in female but not male factor infertility: analysis of 56,564 euploid blastocyst transfers

OBJECTIVE

To evaluate the association of body mass index (BMI) with cycle outcomes after euploid frozen blastocyst transfer.

DESIGN

Retrospective cohort study.

SETTING

Not applicable.

PATIENT(S)

A total of 56,564 first single autologous euploid frozen embryo transfers from the 2016-2019 Society for Assisted Reproductive Technology database were analyzed using BMI and using World Health Organization BMI cohorts. Subanalyses were performed on cycles among patients with a sole diagnosis of polycystic ovary syndrome (PCOS) (n = 4,626) and among patients with only a male factor (n = 10,854).

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Clinical pregnancy, pregnancy loss, and live birth (LB).

RESULT(S)

Success rates and adjusted odds ratios (aORs) with 95% confidence intervals (CIs) for all outcomes were most favorable among those with normal BMI and progressively worsened with increasing BMI. These trends persisted among patients with PCOS for clinical pregnancy (aOR, 0.99; 95% CI, 0.98-0.997), pregnancy loss (aOR, 1.02; 95% CI, 1.01-1.04), and LB (aOR, 0.98; 95% CI, 0.97-0.99), but not among patients with a male factor only for clinical pregnancy (aOR, 1.00; 95% CI, 0.99-1.01), pregnancy loss (aOR, 1.01; 95% CI, 0.99-1.03), or LB (aOR, 0.99; 95% CI, 0.98-1.00).

CONCLUSION(S)

In the largest cohort to date, increasing BMI was associated with decreased pregnancy and LB and increased pregnancy loss after euploid frozen embryo transfers among the entire cohort and among patients with a sole diagnosis of PCOS; however, these results were attenuated among patients with a sole diagnosis of male factor infertility, suggesting that associated female infertility diagnoses and not BMI alone may underlie this trend.

The association between body mass index and live birth and maternal and perinatal outcomes after in-vitro fertilization: a national cohort study

Objective

To investigate the association between female body mass index (BMI) and live birth rates and maternal and perinatal outcomes after in-vitro fertilization (IVF).

Methods

We performed a national, population-based cohort study including women undergoing IVF between 2002 and 2020. The cohort included 126,620 fresh cycles and subsequent frozen embryo transfers between 2007 and 2019 (subpopulation 1) and 58,187 singleton deliveries between 2002 and 2020 (subpopulation 2). Exposure was female BMI (kg/m2) categorized according to the World Health Organization as underweight (<18.5), normal weight (18.5-24.9, reference), overweight (25.0-29.9), class I obesity (30.0-34.9), class II obesity (35.0-39.9), and class III obesity (≥40.0). The primary outcome in subpopulation 1 was cumulative live birth per started fresh IVF cycle, including fresh and subsequent frozen embryo transfers. Primary outcomes in subpopulation 2 were hypertensive disorders of pregnancy and preterm birth at less than 37 weeks. Risk ratios (RRs) with 95% confidence intervals (CIs) for the association between BMI class and outcomes were calculated using generalized linear models after adjustment for relevant confounders.

Results

The cumulative live birth rate decreased significantly with increasing BMI from 32.6% in normal-weight women to 29.4% in overweight women, 27.0% in women in obesity class I, 21.8% in women in obesity class II, and 7.6% in women in obesity class III. The risk of hypertensive disorders of pregnancy increased significantly and progressively with increasing BMI, from 4.6% in normal-weight women to 7.8% in overweight women and 12.5%, 17.9%, and 20.3% in women in obesity classes I, II, and III. The risk of preterm birth followed a similar pattern, from 6.3% in normal-weight women to 7.5% in overweight women and 8.9%, 9.9%, and 15.3% in women in obesity classes I, II, and III. The risks of other perinatal complications, such as perinatal death, showed an even more pronounced increase.

Conclusion

Using a large and complete national cohort of women undergoing IVF, we demonstrate a dose-dependent decrease in live birth rate and a substantial increase in maternal and perinatal complications with increasing BMI. Strategies to improve this situation are warranted.

Validation of prognosis-based in vitro fertilization grant selection criteria

Objective

To validate a prognosis-based scoring system for in vitro fertilization (IVF) grant allocation.

Design

Retrospective cohort study.

Setting

A 501(c)(3) nonprofit foundation that awards donated IVF cycles and grants to those with demonstrated financial need. In contrast to lottery-based or subjective allocation systems, applications are scored according to medical prognostic criteria in addition to personal characteristics.

Patients

Grant recipients from 2015 to 2019.

Interventions

None.

Main outcome measures

Live birth rate (LBR) and cumulative LBR (CLBR) among grant recipients were compared with 2019 Society for Assisted Reproductive Technology (SART) national averages.

Results

A total of 435 applications were reviewed, with 59 grants awarded for 51 autologous IVF cycles, 6 donor oocyte cycles, and 2 gestational carrier cycles, resulting in 39 live births after initial embryo transfer (LBR 61.9%) and 43 CLBRs (CLBR 72.9%). Among autologous cycles, the mean (±SD=3.9 years) age was 31.8 years, and LBR and CLBR were 62.8% and 68.6% vs. 28.2% and 37.1% among all autologous SART cycles, respectively. A subanalysis of grant recipients aged <35 years (n=39) revealed LBR and CLBR of 66.7% and 74.4% vs. 40.7% and 47.8% among autologous SART cycles aged <35 years, respectively.

Conclusions

A scoring system incorporating medical criteria identified IVF grant applicants with a high likelihood of achieving a LB. Although most IVF grant programs select recipients through a lottery or personal characteristics, a prognosis-based scoring system should be considered to maximize LBR in a limited resource setting.

Patient perceptions of body mass index restrictions limiting fertility care for women with high body mass index

RESEARCH QUESTION

What is the patient experience of women with high body mass index (BMI) with BMI restrictions that limit fertility care?

DESIGN

Qualitative study using in-depth, semi-structured interview methodology. Interview transcripts were analysed for iterative themes in accordance with principles of grounded theory.

RESULTS

Forty women with a BMI of 35 kg/m2 or higher with scheduled or completed appointment at the Reproductive Endocrinology and Infertility (REI) clinic completed an interview. Most participants experienced BMI restrictions as unjust. Many perceived that BMI restrictions on fertility care may be medically justified and were in support of weight loss discussions to improve chances of pregnancy; however, several argued that they should have autonomy to commence treatment following an individualized risk assessment. Participants offered recommendations to improve discussion of BMI restrictions and weight loss, including framing the conversation as supportive of their reproductive goals and offering proactive referral to weight loss support to prevent the perception that BMI is a categorical exclusion to future fertility care.

CONCLUSIONS

Participant experiences highlight a need for enhanced strategies for communicating BMI restrictions and weight loss recommendations in ways that are perceived to be supportive of patients' fertility goals without further contributing to weight bias and stigma experienced in medical settings. Opportunities for training to mitigate experiences of weight stigma may be beneficial for clinical and non-clinical staff. Evaluation of BMI policies should be undertaken within the context of clinic policies that permit or prohibit fertility care for other high-risk groups.

Challenges of morbid obesity in gynecological practice

Obesity is currently a global pandemic, with increasing trends worldwide. Data from the WHO, US CDC, and the UK show an increasing trend, with 50% and 25% of the US population expected to be obese and morbidly obese by 2030. Obesity affects several aspects of health, with increased risks of cardiovascular disease, diabetes, metabolic syndrome, and several malignancies. Morbid obesity significantly impacts several aspects of female life and health, from adolescence, through the reproductive years, to the postmenopausal age group. In gynecology, there is a higher prevalence of menstrual disorders and infertility and reduced success rates of assisted reproduction; increased risk of miscarriage; pelvic organ prolapse; and endometrial, ovarian, and breast cancers. Surgery in the patient with morbid obesity is associated with several logistical challenges as well as increased surgical and peri-operative risks and increased cost. In this review, we provide an overview of the current literature, with a focus on challenges of morbid obesity in gynecological practice.

Comparison of two gonadotropin-releasing hormone agonist suppression protocols for in vitro fertilization in young patients with low body mass index

OBJECTIVE

To evaluate two different gonadotropin-releasing (pituitary downregulating) hormones used in in vitro fertilization (IVF) on the live birth rate in young patients with low body mass index (BMI) undergoing their first IVF cycle.

METHODS

In a retrospective study in a single public medical center, 555 long gonadotropin-releasing hormone agonist (GnRH-a) protocols were compared with 431 prolonged GnRH-a protocols between 2016 and 2018. All analyses were performed using the SPSS version 22.0. The primary measured outcome was live birth rate.

RESULTS

Compared with the long protocol, the prolonged protocol required more doses of gonadotropin and a longer duration of ovarian stimulation. Lower levels of serum luteinizing hormone and serum estrogen were detected on the day of chorionic gonadotropin administration, and a lower fertilization rate was found in the prolonged protocol. Although more oocytes were retrieved and more frozen embryos were recorded in the prolonged protocol, the live birth rate per fresh cycle was comparable between the two protocols (P = 0.057). The incidence of ovarian hyperstimulation syndrome was higher in the prolonged protocol group. In the subgroup of women with antral follicle count (AFC) of 12 or less, there was no difference in the live birth rate between the two protocols (P = 0.688). However, for women with AFC > greater than 12, the prolonged protocol was still a positive predictor of live birth rate. The odds ratio was 1.73 (95% confidence interval 1.04-2.89).

CONCLUSION

The prolonged protocol might not increase the live birth rate in women with low BMI who are undergoing their first IVF cycle. However, for women with AFC greater than 12, a prolonged protocol could be a good choice to improve the live birth rate.

Clinical and laboratory parameters associated with pregnancy outcomes in patients undergoing frozen euploid blastocyst transfer

RESEARCH QUESTION

Which factors impact on clinical pregnancy rate (CPR) and live birth rates (LBR) in euploid frozen embryo transfer (eFET) cycles?

DESIGN

Retrospective observational study including 1660 eFET cycles with 2439 euploid blastocysts, from November 2016 to December 2020. The impact of clinical and laboratory parameters on CPR, biochemical miscarriage rate (BMR), clinical miscarriage rate (CMR) and LBR was evaluated.

RESULTS

CPR per transfer was 63.4%, LBR per transfer 51.6%. CPR and LBR were significantly higher when double embryo transfer (DET) was performed (71.6% versus 57.7%, P < 0.001; 55.2% versus 49.1%, P = 0.016, respectively). However, pregnancy loss was significantly higher in the DET group (28.8% versus 22.8%, P = 0.02). When patients were classified by body mass index (BMI), no differences were observed for CPR, but CMR was lower (P < 0.001) and LBR higher (p = 0.031) for the normal BMI group. The natural cycle protocol revealed lower CMR (P < 0.001) and lower pregnancy loss (P < 0.001); subsequently, higher LBR (57.6%, 48.8%, 45.0%, P = 0.001) compared with hormonal replacement protocol and stimulated cycle. Day of trophectoderm biopsy affected CPR (P < 0.001) and LBR (P < 0.001), yet no differences were observed for BMR, CMR or pregnancy loss. The multivariate analysis showed that day 6/7 embryos had lower probabilities for pregnancy; overweight and obesity had a negative impact on LBR, and natural cycle improved LBR (adjusted odds ratio 1.445, 95% confidence interval 0.519-0.806).

CONCLUSIONS

Day of biopsy affected CPR, while BMI and endometrial preparation protocol were associated with LBR in eFET. DET should be discouraged as it will increase the risk of pregnancy loss. Women with higher BMI should be aware of the higher risk of pregnancy loss and lower LBR even though a euploid blastocyst is transferred.

Expression of Markers of Endometrial Receptivity in Obese Infertile PCOS Women before and after the Weight Loss Program-A Preliminary Study

Obesity is an increasing worldwide problem, and it is common in women with polycystic ovaries syndrome (PCOS). It is well known that women with PCOS have lower chances of spontaneous conception as well as lower success with IVF procedures. The mechanisms by which obesity causes lower fertility are not yet fully understood. The aim of the present study was to determine the effect of a lifestyle intervention weight loss program on the expression of the endometrial genes during the window of implantation (WOI). For this purpose, 15 infertile women with obesity and PCOS were included in the study. Endometrial samples were taken during the WOI before and at the end of the program, and RNASeq analysis was performed. There were no significantly differentially expressed genes before and after the weight loss program. We then compared the results of our study with previously published studies on markers of endometrial receptivity. The biomarker genes that were found to be down-regulated during the WOI in previous studies were more down-regulated after the weight loss program in the present study. Furthermore, 25% of the women who achieved the desired 5% or more weight reduction conceived spontaneously. Our study shows that weight loss might positively impact endometrial receptivity. which may lead towards the improved fertility of obese women with PCOS.

The association of obesity with euploidy rates in women undergoing in vitro fertilization with preimplantation genetic testing

PURPOSE

The purpose of this study was to determine the impact of body mass index (BMI) on euploidy rates for in vitro fertilization (IVF) cycles with preimplantation genetic testing (PGT) utilizing primarily next-generation sequencing (NGS).

METHODS

This retrospective cohort study included women aged ≤ 45 years who underwent IVF/PGT between September 2013 and September 2020 at a single university-affiliated fertility center. The primary outcome was euploidy rate. Secondary outcomes included peak serum estradiol (E2), number of oocytes retrieved, oocyte maturation rate, high-quality blastulation rate, clinical loss rate (CLR), clinical pregnancy rate (CPR), and ongoing pregnancy/live birth rate (OPR/LBR).

RESULTS

The study included 1335 IVF cycles that were stratified according to BMI (normal, n = 648; overweight, n = 377; obese, n = 310). The obese group was significantly older with significantly lower baseline FSH, peak E2, high-quality blastulation rate, and number of embryos biopsied than the normal group. Overall euploidy rates were not significantly different between BMI groups (normal 36.4% ± 1.3; overweight 37.3% ± 1.8; obese 32.3% ± 1.8; p = 0.11), which persisted after controlling for covariates (p = 0.82) and after stratification of euploidy rate by age group and by number of oocytes retrieved per age group. There were no significant differences in CLR, CPR, and OPR/LBR across BMI groups.

CONCLUSIONS

Despite a lower high quality blastulation rate with obesity, there is not a significant difference in euploidy rates across BMI groups in women undergoing IVF/PGT.

Outcomes of in-vitro fertilization after bariatric surgery: a national register-based case-control study

STUDY QUESTION

Does previous bariatric surgery (BS) in women affect cumulative live birth rate in IVF?

SUMMARY ANSWER

Women having had BS seem to have the same cumulative live birth rate as non-operated women of the same BMI at IVF treatment.

WHAT IS KNOWN ALREADY

Because of the perinatal risks of obesity to mother and infant as well as impaired outcomes of IVF, obese women are advised to reduce their weight, but it is not clear whether previous BS could affect IVF results.

STUDY DESIGN, SIZE, DURATION

This national register-based case–control study included all cases of BS (n = 30 436) undergoing IVF (n = 153) from 2007 until 2017.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Swedish women between 18 and 45 years operated with BS, with at least one first started cycle of IVF after surgery, were included. For each woman having IVF after BS (n = 153), up to five non-operated control women (n = 744) starting their first IVF cycle during the study period were matched for age, parity and BMI at treatment. The primary outcome in this study was the cumulative live birth rate (CLBR) after the first IVF cycle, defined as all live births after the first cycle including fresh and frozen embryo transfers.

MAIN RESULTS AND THE ROLE OF CHANCE

There was no significant difference in CLBR between the BS group and the matched controls (29.4% compared to 33.1%), even though the number of retrieved oocytes (7.6 vs 8.9, P = 0.005) and frozen embryos (1.0 vs 1.5, P = 0.041) were significantly fewer in the BS group. There was no association between cumulative live birth and BS, adjusted odds ratio 1.04, 95% CI (0.73, 1.51). However, the birth weight was significantly lower in the children born to mothers with previous BS, mean (SD) 3190 (690) vs 3478 (729) g, P = 0.037.

LIMITATIONS, REASONS FOR CAUTION

Confounders such as age, BMI and previous childbirth were accounted for by the matching design of the study, but there were no data on indication for IVF, anti-Müllerian hormone, smoking or previous comorbidities. The study was exploratory and did not reach sufficient power to detect potential smaller differences in live birth rates.

WIDER IMPLICATIONS OF THE FINDINGS

The findings concur with those in previously published smaller studies and provide somewhat reassuring results considering IVF outcomes after BS with a CLBR comparable to that of controls, despite a lower mean birth weight.

STUDY FUNDING/COMPETING INTEREST(S)

This research was funded by grants from the Southern Health Care Region of Sweden. The authors have no competing interests to declare.

TRIAL REGISTRATION NUMBER

N/A.

BMI and miscarriage after IVF

PURPOSE OF REVIEW

To summarize recent findings related to the risk of miscarriage in women with elevated BMI undergoing IVF, and the mechanisms involved in said risk.

RECENT FINDINGS

Miscarriage rates are increased in overweight and obese women in both natural and assisted reproduction. Oocyte and embryo quality assessed according to classic morphological static parameters does not seem to be affected by excessive female body weight. Despite the initial lack of consensus between studies regarding embryo morphokinetics in obese women, blastocyst formation and quality have recently been shown to be similar across BMI groups, even in the case of euploid embryos. However, some metabolomic differences have been described in oocytes and embryos from obese women, thus pointing to a functional alteration. In women with elevated BMI, the percentage of aneuploid embryos is similar to that of normal weight women, and rates of miscarriage are higher, despite the transfer of euploid embryos. Therefore, the origin of the increased pregnancy loss rate after IVF in these women may be related to metabolomic, epigenetic or mitochondrial oocyte and embryo disturbances, or to the abnormal endocrine, metabolic and inflammatory uterine environment induced by obesity, which seems to be also responsible for other numerous complications during pregnancy and the in-utero fetal programming of postnatal diseases. A displacement of the window of implantation in obese women undergoing artificial endometrial preparation has recently been described and may be related to the poorer embryo implantation rates and increased risk of miscarriage observed following fresh and frozen embryo transfers with autologous oocytes, and with donated ova in recipients with extremely high BMI.

SUMMARY

Female obesity is related to poorer outcome in natural and assisted conception, including an increased risk of miscarriage. Embryo morphology, assessed by conventional methods or by morphokinetics, does not seem to be affected by excess weight, with similar blastocyst formation and quality than normal weight women reported in IVF cycles. Embryo aneuploidy is not increased, and higher miscarriages rates are seen after euploid embryo transfer in obese women. Disturbances of the uterus or its environment induced by female obesity seem to be the most likely cause of the increased risk of miscarriage, although metabolomic, epigenetic or mitochondrial oocyte and embryo dysfunction cannot be ruled out as cannot congenital anomalies. In the context of all the above, weight reduction before pregnancy should be advised in obese women trying to become pregnant.

Elevated Body Mass Index in Donor Oocyte Recipients Does Not Affect Implantation of Euploid Embryos

Background: Obesity is a worldwide epidemic that has been shown to have serious implications on health outcomes. Regarding reproductive health, increased body mass index (BMI) reduces fertility and increases the time to conceive. It is unclear how excess weight in females affects the development of oocytes and embryos or the impact of implantation. Materials and Methods: This retrospective single-center study aimed to determine if overweight and obese oocyte recipients had similar pregnancy outcomes compared with healthy weight controls after the transfer of a single euploid frozen-thawed embryo transfer (FET). Five hundred twenty-eight patients who underwent a transfer from 2016 to 2021 were included. The primary outcome studied was the clinical pregnancy (CP) rate. Secondary outcomes included live birth (LB) rate, biochemical pregnancy loss (BPL) rate, and clinical pregnancy loss (CPL) rate. Results: The overall CP rate was 54.9% and did not differ significantly among normal weight (n = 318), overweight (n = 129), and obese (n = 81) BMI categories (0.56 vs. 0.56 vs. 0.49, p = 0.56). There were no significant differences in LB rate (0.47 vs. 0.43 vs. 0.38, p = 0.33), BPL rate (0.14 vs. 0.09 vs. 0.11, p = 0.59), and CPL rate (0.15 vs. 0.21 vs. 0.18, p = 0.38) among BMI groups. Conclusions: Our findings provide support that BMI alone does not adversely alter endometrial receptivity and is not the cause of poor in vitro fertilization (IVF) outcomes in patients with increased BMI. These deleterious IVF outcomes might be to the result of diminished oocyte and/or embryo quality or other factors that have not yet been elucidated.

Effect of Female and Male Body Mass Index on Cumulative Live Birth Rates in the Freeze-all Strategy

CONTEXT

The impact of parental overweight/obese on cumulative live birth rate in in vitro fertilization/intracytoplasmic sperm injection using a freeze-all strategy is still unknown.

OBJECTIVE

To explore the effect of parental body mass index (BMI) on cumulative live birth rate (CLBR) in a freeze-all strategy over 1.5 years.

METHODS

This was a retrospective study in a tertiary care academic medical center; 23 482 patients (35 289 frozen-thawed embryo transfer cycles) were divided into 4 groups according to Asian BMI classification. The main outcome measure was CLBR.

RESULTS

Female overweight/obesity had a lower tendency in CLBR (groups 1-4: optimistic: 69.4%, 67.9%, 62.3%, and 65.7%; conservative: 62.9%, 61.1%, 55.4%, and 57.6%) and prolonged time (groups 1-4: 11.0, 12.2, 15.9, and 13.8 months for 60% CLBR in the optimistic method; 8.7, 9.5, 11.7, 11.0 months for 50% CLBR in the conservative method). The same trend to a lesser extent was also observed in male BMI groups. When combining parental BMI, "parental overweight/obesity" had lower CLBR and longer time for reaching CLBR >50% (optimistic: 4.5 months for 60% CLBR; conservative: 3 months for 50% CLBR), followed by "only female high BMI" (optimistic: 2.1 months for 60% CLBR; conservative: 1.7 months for 50% CLBR), while "only male high BMI" had no influence.

CONCLUSION

Our results showed the importance of parental BMI, female BMI, and male BMI on the 1.5-year CLBR using a freeze-all strategy; the time to reach the CLBR (60% in optimistic, 50% in conservative) for overweight and obese patients was several months, but it is not as long as losing weight.

Fresh embryo transfer after in vitro insemination of fresh vs. cryopreserved anonymous donor oocytes: which has a better live birth rate? A Society for Assisted Reproductive Technology Clinic Outcome Reporting System analysis

OBJECTIVE

To determine if transfer of fresh embryos derived from fresh or cryopreserved donor oocytes yields a higher live birth rate.

DESIGN

Historical cohort study.

SETTING

Society for Assisted Reproductive Technology Clinic Outcome Reporting System database.

PATIENT(S)

A total of 24,663 fresh embryo transfer cycles of donor oocytes.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

The primary outcome was live births per number of embryos transferred on day 5. The secondary outcomes included number of infants per embryo transfer, surplus embryos cryopreserved, and characterization of US oocyte recipients.

RESULT(S)

A total of 16,073 embryo transfers were from fresh oocytes and 8,590 were from cryopreserved oocytes. Recipient age, body mass index (BMI), gravidity, and parity were similar between the groups. Most recipients were of White non-Hispanic race (66.9%), followed by Asian (13.7%), Black non-Hispanic (9.3%), and Hispanic (7.2%). Fresh oocyte cycles were more likely to use elective single embryo transfer (42.5% vs. 37.8%) or double embryo transfer (53.2% vs. 50.4%) and resulted in more surplus embryos for cryopreservation (4.6 vs. 1.2). The live birth rate from fresh oocytes was 57.5% vs. 49.7% from cryopreserved oocytes. Negative predictors of live birth included the use of cryopreserved oocytes (odds ratio [OR] 0.731, 95% confidence interval [CI] 0.665-0.804), Black non-Hispanic race (OR 0.603, 95% CI 0.517-0.703), Asian race (OR 0.756, 95% CI 0.660-0.867), and increasing recipient BMI (OR 0.982, 95% CI 0.977-0.994) after controlling for recipient age, number of embryos transferred on day 5, and unexplained infertility diagnosis. The proportion of multifetal deliveries was greater in cycles utilizing fresh (26.4%) vs. cryopreserved (20.6%) oocytes.

CONCLUSION(S)

The live birth rate is higher with use of fresh oocytes vs. cryopreserved oocytes in fresh embryo transfer cycles. Negative live birth predictors include recipient Black non-Hispanic or Asian race and increasing BMI.

Body mass index is associated with miscarriage rate and perinatal outcomes in cycles with frozen-thawed single blastocyst transfer: a retrospective cohort study

Background

The association between body mass index (BMI) and IVF cycle outcomes remain inconclusive. In addition, the impact of BMI on perinatal outcomes has been less well-studied. The aim of this study was to assess the effects of BMI on pregnancy outcomes, as well as maternal and neonatal outcomes.

Methods

This was a retrospective cohort study on 10,252 frozen-thawed cycles with single blastocyst transfer between January 2016 and December 2019. Patients were divided into four groups: underweight (< 18.5 kg/m²), normal-weight (18.5–24 kg/m²), overweight (24–28 kg/m²), and obesity (≥ 28 kg/m²), according to the Chinese classification. Multivariate logistic regression and multivariate general linear model were used for statistical analysis.

Results

The rates of live birth and clinical pregnancy were comparable among groups. Miscarriage rate was higher in the obese women than that in the normal controls (27.51 vs. 20.91%, aOR = 1.453 (1.066–1.982)). Using the normal-weight women as reference, the underweight women had lower incidences of preterm birth (6.97 vs. 11.19%, aOR = 0.611 (0.422–0.884)), macrosomia (4.90 vs. 8.65%, aOR = 0.544 (0.353–0.837)) and large-for-gestational age (LGA, 11.18 vs. 16.54%, aOR = 0.643 (0.477–0.866)); the overweight women had higher prevalence of gestational diabetes (6.56 vs. 3.82%, aOR = 1.744 (1.232–2.468)), hypertension (4.42 vs. 2.32%, aOR = 1.822 (1.186–2.800)), macrosomia (12.93 vs. 8.65%, aOR = 1.596 (1.240–2.054)) and LGA (23.22 vs. 16.54%, aOR = 1.549 (1.270–1.890)); the obese women had higher incidences of preterm birth (16.87 vs. 11.19%, aOR = 1.646 (1.068–2.536)), cesarean delivery (93.98 vs. 87.91%, aOR = 2.078 (1.083–3.987)), gestational hypertension (4.82 vs. 2.32%, aOR = 2.138 (1.005–4.547)), macrosomia (14.88 vs. 8.65%, aOR = 1.880 (1.192–2.964)) and LGA (25.60 vs. 16.54%, aOR = 1.764 (1.218–2.555)).

Conclusions

BMI has no significant effect on the chance of pregnancy or live birth, but obesity increases the risk of miscarriage. Underweight is associated with better maternal and neonatal outcomes, while overweight and obesity are associated with worse maternal and neonatal outcomes.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12884-022-04443-2.

Association between clinical and IVF laboratory parameters and miscarriage after single euploid embryo transfers

BACKGROUND

The goal of this study was to investigate which factors, excluding embryo aneuploidies, are associated with miscarriage in patients who have undergone a single euploid blastocyst transfer.

METHODS

Retrospective, observational and multicenter study with 2832 patients undergoing preimplantational genetic testing for aneuploidies (PGT-A) due to repeated implantation failure, recurrent pregnancy loss, advanced maternal age or severe male factor were transferred one single euploid embryo.

RESULTS

One of the main findings was a significant relationship between body mass index (BMI) and miscarriage rates (13.4% in underweight women, 12.1% in normal weight, 14.5% in overweight, and 19.2% in obese women, odds ratio [OD] 1.04; 95% confidence interval [CI], 1.01-1.07 p = 0.006). Endometrial thickness (OD 0.65; 95%, 0.52-0.77 p = 0.04) and type of endometrial preparation (natural cycle or hormone replacement cycle) (OD 0.77; 95%, 0.52-0.77, p = 0.04) were also associated with miscarriage rates.

CONCLUSIONS

BMI was strongly associated to miscarriage rates. We also observed a weaker association with endometrial thickness and with the type of endometrial preparation (natural cycle or hormone replacement cycle). None of the other studied variables (biopsy day, maternal and male age, duration of infertility, cycle length, previous miscarriages, previous live births, previous In Vitro Fertilization (IVF) cycles, endometrial pattern and/or diagnosis) were associated with miscarriage rates.

Factors affecting live birth rates in donor oocytes from commercial egg banks vs. program egg donors: an analysis of 40,485 cycles from the Society for Assisted Reproductive Technology registry in 2016-2018

OBJECTIVE

To examine the differences in live birth rates (LBRs), with single embryo transfer (SET), using oocytes from program generated egg donors vs. commercial egg bank donors and other factors affecting LBRs using donor oocytes.

DESIGN

Retrospective cohort study.

SETTING

Not applicable.

PATIENT(S)

A total of 40,485 in vitro fertilization cycles using donor oocytes reported to the Society for Assisted Reproductive Technology registry in 2016-2018.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Live birth rate and cumulative LBR for SET using donor oocytes.

RESULT(S)

Multivariate results from the first SET from 19,128 cycles, including 15,429 from program generated egg donors and 3,699 from commercial egg banks, showed, when controlling for all other variables, the following: the LBR in the first SET cycle using commercial egg banks was 53.3% compared with 55.4% using program recruited egg donors (odds ratio [OR], 0.92); a reduction in the LBR with increasing recipient age, ages 40-44 years (OR, 0.80), 45-49 years (OR, 0.77), and >49 years (OR, 0.65); a steady decline in the LBR with increases in recipient body mass index above normal; and a steady increase in the LBR in association with >16 oocytes retrieved. Double embryo transfer increased the LBR (SET, 52%, vs. double embryo transfer, 58%) but also significantly increased the multiple pregnancy LBR, with 43% twins and 0.9% triplets. Blastocyst transfer had a higher LBR than cleavage stage embryos (52.5% vs. 39.5%). Intracytoplasmic sperm injection vs. conventional insemination when using fresh oocytes from program donors had similar LBRs.

CONCLUSION(S)

When performing in vitro fertilization using donor oocytes with SET, the LBR is affected by oocyte source, recipient age, recipient body mass index, stage of embryo at transfer, and number of oocytes retrieved.

Blastocyst formation is similar in obese and normal weight women: a morphokinetic study

STUDY QUESTION

Does the embryo cleavage pattern and rate of blastocyst formation differ between normal weight and obese women undergoing IVF?

SUMMARY ANSWER

Embryo morphokinetic development, final blastocyst formation rate and blastocyst morphology do not differ between obese and normal weight women.

WHAT IS KNOWN ALREADY

Female obesity has been related to impaired IVF outcomes. Although the mechanisms responsible for this detrimental effect are thought to include impaired oocyte and embryo quality and reduced endometrial receptivity, they are yet to be confirmed. Embryo quality has been commonly assessed using static morphological criteria. Only three studies have analysed the progress of embryos up to the blastocyst stage in women with elevated BMI, but they have used small samples of patients or have obtained contradictory results.

STUDY DESIGN, SIZE, DURATION

This retrospective, cohort study, was performed from January 2016 to May 2020. A total of 3316 ICSI cycles from 2822 women were included, of which 1251 cycles were part of a preimplantation genetic testing programme. In total, 17 848 embryos were analysed.

PARTICIPANTS/MATERIALS, SETTING, METHODS

This study reports on the IVF cycles of infertile women, with a known BMI, who underwent ICSI and whose embryos were grown until the fifth/sixth day of development in a time-lapse system. Patients were grouped as follows. Underweight was defined as a BMI <18.5 kg/m2; normal weight was a BMI of 18.5-24.9 kg/m2; overweight was a BMI of 25-29.9 kg/m2; and obesity was a BMI of ≥30 kg/m2. Embryo development was assessed on an external computer with analysis software.

MAIN RESULTS AND THE ROLE OF CHANCE

Despite an initial slower pattern of embryo development, the blastocyst formation rate on day 5 or on day 5 plus day 6 did not differ in obese women with respect to the other three BMI groups. Moreover, based on the evaluation of inner cell mass and the trophectoderm on both days of blastocyst development, embryo quality was similar across the BMI groups, as were the pattern of development and arrest up to blastocyst formation and the distribution of the categories of full, expanded and hatching blastocysts.

LIMITATIONS, REASONS FOR CAUTION

Limitations include the retrospective analysis of data, the use of BMI as the only parameter to define normal/abnormal female body weight, and the lack of complete information about clinical outcomes.

WIDER IMPLICATIONS OF THE FINDINGS

Blastocyst formation and embryo morphokinetics are not affected by female obesity, and the poorer IVF outcomes described for such women are probably due to deficient endometrial receptivity. The role of endometrial progesterone exposure on the day of embryo transfer should be analysed in future studies as a possible determining factor.

STUDY FUNDING/COMPETING INTEREST(S)

No external funding was used and there are no competing interests.

TRIAL REGISTRATION NUMBER

N/A.

Obesity and reproduction: a committee opinion

The purpose of this American Society for Reproductive Medicine Practice Committee report is to provide clinicians with principles and strategies for the evaluation and treatment of couples with infertility associated with obesity. This revised document replaces the Practice Committee document titled "Obesity and reproduction: an educational bulletin" last published in 2015 (Fertil Steril 2015;104:1116-26).

Lifestyle intervention prior to IVF does not improve embryo utilization rate and cumulative live birth rate in women with obesity: a nested cohort study

STUDY QUESTION

Does lifestyle intervention consisting of an energy-restricted diet, enhancement of physical activity and motivational counseling prior to IVF improve embryo utilization rate (EUR) and cumulative live birth rate (CLBR) in women with obesity?

SUMMARY ANSWER

A 6-month lifestyle intervention preceding IVF improved neither EUR nor CLBR in women with obesity in the first IVF treatment cycle where at least one oocyte was retrieved.

WHAT IS KNOWN ALREADY

A randomized controlled trial (RCT) evaluating the efficacy of a low caloric liquid formula diet (LCD) preceding IVF in women with obesity was unable to demonstrate an effect of LCD on embryo quality and live birth rate: in this study, only one fresh embryo transfer (ET) or, in case of freeze-all strategy, the first transfer with frozen-thawed embryos was reported. We hypothesized that any effect on embryo quality of a lifestyle intervention in women with obesity undergoing IVF treatment is better revealed by EUR and CLBR after transfer of all fresh and frozen-thawed embryos.

STUDY DESIGN, SIZE, DURATION

This is a nested cohort study within an RCT, the LIFEstyle study. The original study examined whether a 6-month lifestyle intervention prior to infertility treatment in women with obesity improved live birth rate, compared to prompt infertility treatment within 24 months after randomization. In the original study between 2009 and 2012, 577 (three women withdrew informed consent) women with obesity and infertility were assigned to a lifestyle intervention followed by infertility treatment (n = 289) or to prompt infertility treatment (n = 285).

PARTICIPANTS/MATERIALS, SETTING, METHODS

Only participants from the LIFEstyle study who received IVF treatment were eligible for the current analysis. In total, 137 participants (n = 58 in the intervention group and n = 79 in the control group) started the first cycle. In 25 participants, the first cycle was cancelled prior to oocyte retrieval mostly due to poor response. Sixteen participants started a second or third consecutive cycle. The first cycle with successful oocyte retrieval was used for this analysis, resulting in analysis of 51 participants in the intervention group and 72 participants in the control group. Considering differences in embryo scoring methods and ET day strategy between IVF centers, we used EUR as a proxy for embryo quality. EUR was defined as the proportion of inseminated/injected oocytes per cycle that was transferred or cryopreserved as an embryo. Analysis was performed per cycle and per oocyte/embryo. CLBR was defined as the percentage of participants with at least one live birth from the first fresh and subsequent frozen-thawed ET(s). In addition, we calculated the Z-score for singleton neonatal birthweight and compared these outcomes between the two groups.

MAIN RESULTS AND THE ROLE OF CHANCE

The overall mean age was 31.6 years and the mean BMI was 35.4 ± 3.2 kg/m² in the intervention group, and 34.9 ± 2.9 kg/m² in the control group. The weight change at 6 months was in favor of the intervention group (mean difference in kg vs the control group: −3.14, 95% CI: −5.73 to −0.56). The median (Q25; Q75) number of oocytes retrieved was 4.00 (2.00; 8.00) in the intervention group versus 6.00 (4.00; 9.75) in the control group, and was not significantly different, as was the number of oocytes inseminated/injected (4.00 [2.00; 8.00] vs 6.00 [3.00; 8.75]), normal fertilized embryos (2.00 [0.50; 5.00] vs 3.00 [1.00; 5.00]) and the number of cryopreserved embryos (2.00 [1.25; 4.75] vs 2.00 [1.00; 4.00]). The median (Q25; Q75) EUR was 33.3% (12.5%; 60.0%) in the intervention group and 33.3% (16.7%; 50.0%) in the control group in the per cycle analysis (adjusted B: 2.7%, 95% CI: −8.6% to 14.0%). In the per oocyte/embryo analysis, in total, 280 oocytes were injected or inseminated in the intervention group, 113 were utilized (transferred or cryopreserved, EUR = 40.4%); in the control group, EUR was 30.8% (142/461). The lifestyle intervention did not significantly improve EUR (adjusted odds ratio [OR]: 1.36, 95% CI: 0.94–1.98) in the per oocyte/embryo analysis, taking into account the interdependency of the oocytes per participant. CLBR was not significantly different between the intervention group and the control group after adjusting for type of infertility (male factor and unexplained) and smoking (27.5% vs 22.2%, adjusted OR: 1.03, 95% CI: 0.43–2.47). Singleton neonatal birthweight and Z-score were not significantly different between the two groups.

LIMITATIONS, REASONS FOR CAUTION

This study is a nested cohort study within an RCT, and no power calculation was performed. The randomization was not stratified for indicated treatment, and although we corrected our analyses for baseline differences, there may be residual confounding. The limited absolute weight loss and the short duration of the lifestyle intervention might be insufficient to affect EUR and CLBR.

WIDER IMPLICATIONS OF THE FINDINGS

Our data do not support the hypothesis of a beneficial short-term effect of lifestyle intervention on EUR and CLBR after IVF in women with obesity, although more studies are needed as there may be a potential clinically relevant effect on EUR.

STUDY FUNDING/COMPETING INTEREST(S)

The study was supported by a grant from ZonMw, the Dutch Organization for Health Research and Development (50-50110-96-518). A.H. has received an unrestricted educational grant from Ferring pharmaceuticals BV, The Netherlands. B.W.J.M. is supported by an NHMRC Investigator grant (GNT1176437). B.W.J.M. reports consultancy for Guerbet, has been a member of the ObsEva advisory board and holds Stock options for ObsEva. B.W.J.M. has received research funding from Guerbet, Ferring and Merck. F.J.M.B. reports personal fees from membership of the external advisory board for Merck Serono and a research support grant from Merck Serono, outside the submitted work.

TRIAL REGISTRATION NUMBER

The LIFEstyle RCT was registered at the Dutch trial registry (NTR 1530). https://www.trialregister.nl/trialreg/admin/rctview.asp?TC=1530.

Obesity Affects Endometrial Receptivity by Displacing the Window of Implantation

Our aim was to determine prospectively whether increased body mass index (BMI) affects endometrial receptivity through displacement of the window of implantation (dWOI) using the endometrial receptivity analysis (ERA), and whether this effect is BMI-dependent. We recruited a population of 170 infertile women with a normal uterus and no clinical history of recurrent miscarriage or implantation failure. These women were divided into four groups according to BMI: normal weight (18.5-24.9 kg/m²; n = 44), overweight (25-29.9 kg/m²; n = 29), class I obese (30.0-34.9 kg/m²; n = 54), and class II and III obese (> 35 kg/m²; n = 43). We also assigned the patients to one of two larger BMI cohorts: non-obese (normal weight and overweight; n = 73) and obese (class I, II, and III obese; n = 97). We compared analytical and clinical data and dWOI in these categories, finding significant metabolic differences in glycemia, TSH, insulin, HDL cholesterol, LDL cholesterol, triglycerides, and systolic and diastolic blood pressure among the different BMI groups. One-day dWOI increased significantly with BMI, and significant differences were observed in the non-obese versus obese categories (9.7% vs 25.3 %, respectively (p = 0.02)). dWOI was most pronounced in patients with class II-III obesity. In addition, displacement was longer as BMI increased since ERA revealed a higher proportion of displacements of 1 day than of 12 h and showed they were predominantly pre-receptive. In conclusion, obesity has a negative effect on endometrial receptivity through delaying of the WOI, which increases in function of BMI as well as the metabolic disturbances of the patient.

Factors predicting clinical outcomes from 494 vitrified oocyte donation cycles at a UK-regulated egg bank

RESEARCH QUESTION

Do donor age, AMH, AFC, BMI and reproductive history predict response to ovarian stimulation? Do donor and recipient clinical markers and embryology parameters predict recipient pregnancy and live birth?

DESIGN

Retrospective cohort study of 494 altruistic oocyte donors aged 18-35 years; 340 were matched to 559 recipients. Predictors of donor total oocyte yield and total mature oocyte yield were identified. Total and mature oocyte number were compared according to stratified donor AMH and age. Donor, recipient and embryology parameters predictive of recipient primary outcomes (clinical pregnancy and live birth) were identified.

RESULTS

Donor age and AMH predicted total oocyte yield (P = 0.030 and P < 0.001)) and total mature oocyte yield (P = 0.011 and P < 0.001). Donors aged 30-35 years with AMH 15-29.9 pmol/l had lower total oocyte yield (P = 0.004) and mature oocyte yield (P < 0.001) than donors aged 18-24 years. Up to an AMH threshold of 39.9 pmol/l, increasing AMH levels predicted higher total oocyte yield (<15 pmol/l versus 15-29.9 pmol/l, P = 0.001; 15-29.9 pmol/l versus 30-39.9 pmol/l, P < 0.001; 30-39.9pmol/l versus ≥ 40 pmol/l, P = 1.0) and mature oocyte yield (<15 pmol/l versus 15-29.9 pmol/l, P = 0.005; 15-29.9 pmol/l versus 30-39.9 pmol/l, P = 0.006; 30-39.9 pmol/l versus ≥40 pmol/l, P = 1.0). In recipients, the rate of transferrable embryos per oocytes received, fertilized and number of embryo transfers needed to achieve the primary outcome were predictors of cumulative clinical pregnancy (P = 0.011, P = 0.017 and P < 0.001) and live birth (P = 0.008, P = 0.012 and P < 0.001) rates. Recipient BMI (P = 0.024) and previous miscarriages (P = 0.045) were predictors of cumulative live birth rate. Donor age 18-22 years was associated with a lower incidence of recipient clinical pregnancy (P = 0.004) and live birth (P = 0.001) after the first embryo transfer versus donor age 23-29 years.

CONCLUSIONS

Donor age and AMH are independent predictors of oocyte yield. Raised recipient BMI and history of miscarriages reduce cumulative live birth rates, which may be increased by selecting donors aged 23-29 years, instead of younger donors.

Body mass index is not associated with embryo ploidy in patients undergoing in vitro fertilization with preimplantation genetic testing

OBJECTIVE

To assess the association between body mass index (BMI) and embryo aneuploidy and mosaicism in a cohort of patients undergoing in vitro fertilization (IVF) with trophectoderm biopsy for preimplantation genetic testing for aneuploidy (PGT-A) using next-generation sequencing technology.

DESIGN

Retrospective cohort study.

SETTING

Academic center.

PATIENTS

Patients undergoing their first IVF cycle with trophectoderm biopsy and PGT-A at our center between January 1, 2017, and August 31, 2020. Patients classified as underweight on the basis of BMI (BMI <18.5 kg/m²) and patients who underwent fresh embryo transfers were excluded.

INTERVENTION

None.

MAIN OUTCOME MEASURES

Number and proportion of aneuploid, mosaic, and euploid embryos.

RESULTS

The patients were stratified according to the World Health Organization's BMI classification: normal weight (18.5-24.9 kg/m², n = 1,254), overweight (25-29.9 kg/m², n = 351), and obese (≥30 kg/m², n = 145). Age-adjusted regression models showed no relationship between BMI classification and the number or proportion of aneuploid embryos. There were no statistically significant associations between BMI classifications and the number or proportion of mosaic or euploid embryos. A subgroup analysis of patients classified into age groups of <35, 35-40, and >40 years similarly showed no relationships between BMI and embryo ploidy outcomes.

CONCLUSION

Body mass index was not associated with the number or proportion of aneuploid, mosaic, or euploid embryos in this large cohort of patients undergoing IVF with PGT-A, suggesting that the negative effect of excess weight on reproductive outcomes was independent of the ploidy status of the embryo cohort.

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.

The Appraisal of Body Content (ABC) trial: Increased male or female adiposity does not significantly impact in vitro fertilization laboratory or clinical outcomes

OBJECTIVE

To investigate the impact of obesity as determined by bioelectric impedance analysis (BIA) and body mass index (BMI) on in vitro fertilization (IVF) laboratory and clinical outcomes.

DESIGN

Prospective cohort study.

SETTING

Academic-affiliated private practice.

PATIENT(S)

A total of 1,889 infertile couples undergoing IVF from June 2016 to January 2019.

INTERVENTION(S)

Female patients and male partners underwent BIA and BMI measurement at the time of oocyte retrieval. Embryology and clinical outcomes were prospectively tracked with comparison groups determined by percentage of body fat (%BF) and BMI categories.

MAIN OUTCOME MEASURE(S)

Fertilization rate, blastocyst formation rate, euploidy rate, miscarriage rate, sustained implantation rate, live birth rate, rates of low birth weight/very low birth weight, prematurity rates.

RESULT(S)

Fertilization rates and euploidy rates were equivalent among all women. Blastocyst formation rates were slightly higher (55%) in women with an obese %BF compared with all other %BF categories (51%); however, this trend was not noted in women defined as obese by BMI. Miscarriage rates, sustained implantation rates, and live birth rates were equivalent among all women. The rate of very low birth weight was low but increased in obese women (3%) versus underweight, normal-weight, and overweight counterparts (0%-1.3%) as determined by %BF and BMI. Obesity in men did not significantly affect any embryologic or clinical outcomes.

CONCLUSION(S)

Although maternal obesity imposes a small but increased risk of very low birth weight infants, most embryology and pregnancy outcomes are equivalent to normal weight patients. Paternal obesity does not appear to affect IVF, pregnancy, or delivery outcomes.

Preconception Evaluation Before In Vitro Fertilization

Importance

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

Objective

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

Evidence Acquisition

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

Results

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

Conclusion and Relevance

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

Live birth outcomes in infertile patients with class III and class IV obesity following fresh embryo transfer

OBJECTIVE

Assess the effect of class III (body mass index [BMI, kg/m2] 40-49.9) and class IV obesity (≥ 50) on clinical pregnancy and live birth outcomes after first oocyte retrieval and fresh embryo transfer cycle.

DESIGN

Cohort study SETTING: Academic center PATIENTS: Patients undergoing their first oocyte retrieval with planned fresh embryo transfer in our clinic between 01/01/2012 and 12/31/2018. Patients were stratified by BMI: 18.5-24.9 (n = 4913), 25-29.9 (n = 1566) 30-34.9 (n = 559), 35-39.9 (n = 218), and ≥ 40 (n = 114).

INTERVENTION

None MAIN OUTCOME MEASURE: Live birth rate RESULTS: Following embryo transfer, there were no differences in pregnancy rates across all BMI groups (p value, linear trend = 0.86). However among pregnant patients, as BMI increased, a significant trend of a decreased live birth rate was observed (p value, test for linear trend = 0.004). Additionally, as BMI increased, a significant trend of an increased miscarriage rate was observed (p value, linear trend = < 0.001). Compared to the normal-weight cohort, women with a BMI ≥ 40 had a significantly higher rate of cancelled fresh transfers after retrieval (18.4% vs. 8.2%, OR 2.51; 95%CI 1.55-4.08). Among singleton deliveries, a significant trend of an increased c-section rate was identified as the BMI increased (p value, linear trend = <0.001).

CONCLUSION

Overall, patients with a BMI > 40 have worse IVF treatment outcomes compared to normal-weight patients. After embryo transfer, their pregnancy rate is comparable to normal-weight women; however, their miscarriage rate is higher, leading to a lower live birth rate for pregnant women in this population. Patients with a BMI > 40 have a c-section rate that is 50% higher than normal-weight patients.

Female obesity increases the risk of miscarriage of euploid embryos

OBJECTIVE

To determine whether female body mass index (BMI) is associated with an increased risk of miscarriage after euploid embryo transfer.

DESIGN

A retrospective, observational, multicenter cohort study.

SETTING

University-affiliated in vitro fertilization center.

PATIENT(S)

In this study, 3,480 cycles of in vitro fertilization with preimplantation genetic testing for aneuploidy (PGT-A) in the blastocyst stage and euploid embryo transfer were divided into four groups according to patient BMI.

INTERVENTION(S)

In vitro fertilization with PGT-A.

MAIN OUTCOME MEASURE(S)

The primary outcome was the miscarriage rate, which included both biochemical and clinical miscarriages. Secondary outcomes were implantation, pregnancy, clinical pregnancy, and live birth rates.

RESULT(S)

Cycles were divided into four groups according to BMI (kg/m²): underweight (<18.5; n = 155), normal weight (18.5-24.9; n = 2,549), overweight (25-29.9; n = 591), and obese (≥30; n = 185). The number of PGT-A cycles per patient was similar in the four groups. Fertilization rate, day of embryo biopsy, technique of chromosomal analysis, number of euploid embryos, number of transferred embryos, and method of endometrial preparation for embryo transfer were similar in the four BMI groups. Miscarriage rates were significantly higher in women with obesity compared to women with normal weight, mainly due to a significant increase in the clinical miscarriage rates. Live birth rates also were lower in women with obesity. Obesity in women and day 6 trophectoderm biopsy were found to influence the reduced live birth rate.

CONCLUSION(S)

Women with obesity experience a higher rate of miscarriage after euploid embryo transfer than women with a normal weight, suggesting that other mechanisms than aneuploidy are responsible for this outcome.

Live birth rate from euploid blastocysts is not associated with infertility etiology or oocyte source following frozen-thawed embryo transfer (FET): analysis of 4148 cycles reported to SART CORS

PURPOSE

To investigate whether live birth rates from euploid blastocyst frozen-thawed embryo transfer (FET) cycles are associated with infertility diagnosis or oocyte source.

DESIGN

Retrospective analysis of FET cycles reported to SART CORS in 2014.

METHODS

Data from fresh IVF cycles with preimplantation genetic testing for aneuploidy (PGT-A), linked to the first FET cycles, were collected from the 2014 SART CORS database for autologous and donor oocyte cycles. Inclusion criteria were patients undergoing FET with euploid embryos (n = 4148). Demographic data including age, BMI, prior fertility, and etiology of infertility were collected from the retrieval cycle and analyzed. Patients with uterine anomalies, preimplantation genetic testing-mutation (PGT-M) for genetic diseases, gender selection, HLA determination, or systemic and immunologic disorders were excluded. The primary outcome measure was live birth (LB) rate. Potential confounders such as age, prior fertility, and maximum baseline FSH values were analyzed with regression models as indicated.

RESULTS

Though age, maximum baseline FSH, and infertility diagnosis were significantly different, LB was similar between patients undergoing autologous or donor oocyte FET cycles. Etiology of infertility was not significantly associated with LB in autologous cycles (p = 0.95). Potential confounders such as maternal age, prior fertility, and maximum baseline FSH were not associated with outcomes; however, maternal BMI was inversely related to LB in autologous cycles, with an odds ratio of 0.97 (95% CI: 0.96-0.98 (rho = - 0.08, p < 0.01)).

CONCLUSIONS

After controlling for confounding variables, a euploid embryo derived from a donor or autologous oocyte results in similar LB in women with different infertility diagnoses.

The effects of oocyte donor and recipient body mass index on live birth rates and pregnancy outcomes following assisted reproduction

Objective

To investigate the effects of oocyte donor and recipient body mass index (BMI) on outcomes of vitrified donor oocyte assisted reproductive technology (ART).

Design

Retrospective cohort study.

Setting

Private fertility center.

Patient(s)

A total of 338 oocyte donors and 932 recipients who underwent 1,651 embryo transfer cycles in 2008–2015.

Intervention(s)

Multivariable log binomial regression models with cluster-weighted generalized estimating equations were used to estimate the adjusted risk ratios.

Main Outcome Measure(s)

Live birth, defined as the delivery of at least one live-born infant, including all embryo transfer cycles. Secondary outcomes included birth weight and gestational length only among singleton live births.

Results

The mean ± SD body mass indexes (BMIs) of donors and recipients were 22.6 ± 2.5 kg/m² and 24.6 ± 4.8 kg/m², respectively. There were no significant associations between donor BMI and probability of live birth. Recipients with BMI ≥35 kg/m² had a significantly higher probability of live birth compared with normal-weight recipients. Among singleton live births, recipients with BMI <18.5 kg/m² had a lower risk whereas women with BMI ≥35 kg/m² had a higher risk of delivery in an earlier gestational week compared with normal weight women. Recipients with a BMI ≥35 kg/m² also had a higher risk of having a low birth weight infant compared with normal-weight women.

Conclusions

In the setting of vitrified donor oocyte ART, recipient BMI was positively associated with probability of live birth but negatively associated with gestational length and birth weight among singleton births.

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.

Effect of a Combination of Myo-Inositol, Alpha-Lipoic Acid, and Folic Acid on Oocyte Morphology and Embryo Morphokinetics in non-PCOS Overweight/Obese Patients Undergoing IVF: A Pilot, Prospective, Randomized Study

Herein we aimed at assessing whether Myo-Inositol (MI), Alpha–Lipoic acid (ALA), and Folic acid (FA) could improve oocyte quality and embryo development in non-PCOS overweight/obese women undergoing IVF. Three hundred and twenty-four mature oocytes were obtained from non-PCOS overweight/obese patients, randomized to receive either MI, ALA, and FA (MI + ALA + FA group, n = 155 oocytes) or FA alone (FA-only group, n = 169 oocytes). Oocytes were examined using Polarized Light Microscopy to assess morphological features of zona pellucida (ZP) and meiotic spindle (MS). One hundred and seventy-six embryos (n = 84 in the MI + ALA + FA group, n = 92 in the FA-only group) were assessed by conventional morphology on days 2 and 5, as well as using the Time-Lapse System morphokinetic analysis. A significantly higher ZP retardance, area, and thickness (p < 0.05), and a shorter MS axis (p < 0.05) were observed in the MI + ALA + FA group, suggesting a positive effect on oocyte quality. Conventional morphology evaluation on day 2 showed a higher mean embryo score in the MI + ALA + FA group, whereas embryo morphokinetic was comparable in the two groups. Overall, our data show a possible beneficial effect of the combination of MI, ALA, and FA on oocyte and embryo morphology, encouraging testing of this combination in adequately powered randomized trials to assess their impact of clinical IVF results.

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.

Genetic testing on products of conception and its relationship with body mass index

PURPOSE

The study aimed to investigate the relationship between elevated maternal body mass index (BMI) and foetal chromosomal aberrations by performing single-nucleotide polymorphism (SNP) array-based genetic testing on products of conception (POC).

METHODS

We retrospectively reviewed the data for 1068 assisted reproductive technology (ART)-conceived POC originated from 1068 patients with early spontaneous miscarriage. First, all types of chromosomal abnormalities were defined. Then, the baseline characteristics, including maternal age, BMI, thyroid-stimulating hormone (TSH), gestational age, fertilization method, reasons for fertility treatment, embryo transfer (ET) cycle, stage of embryo development and the embryo morphology grade, were compared between chromosomally normal and abnormal POC groups. Finally, a multivariate logistic regression model was used to analyse various factors affecting the foetal chromosomal abnormality rate.

RESULTS

The SNP array results showed that 45.3% (484/1068) of POC were chromosomally normal and that 54.7% (584/1068) of POC presented chromosomal abnormalities. Of these 584 chromosomally abnormal POC, 388 (66.4%) were trisomy, 42 (7.2%) had a monosomy, 68 (11.6%) were found with segmental aneuploidy, 46 (7.9%) were mosaic, 28 (4.8%) were identified as polyploidy and 12 (2.1%) were euploid samples with uniparental disomy (UPD). Multivariate logistic regression results showed that the risk of miscarrying chromosomally abnormal POC increased 1.424-fold in women with normal BMI compared to women with an elevated BMI (≥ 25 kg/m²) (OR = 1.424, 95% CI = 1.074-1.888, p = 0.014).

CONCLUSION

Women with an elevated BMI (≥ 25 kg/m²) are more likely to miscarry chromosomally normal POC.

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

BACKGROUND

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

OBJECTIVE AND RATIONALE

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

SEARCH METHODS

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

OUTCOMES

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

WIDER IMPLICATIONS

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

Predictive factors for successful pregnancy in an egg-sharing donation program

Objective

To investigate the predictive factors for successful pregnancy in oocyte recipient ICSI cycles in an egg-sharing donation program.

Methods

Analysed data were obtained via chart review of 1505 vitrified oocytes donated from 268 patients to 225 oocyte recipients, undergoing 307 ICSI cycles. Patients were participating in an egg-sharing donation program between January 2015 and May 2017. Adjusted generalised linear models were used to investigate the impact of oocyte donor and recipient characteristics on recipients’ pregnancy achievement.

Results

Implantation rate in the oocyte donor was highly correlated with pregnancy achievement in the oocyte recipient’s cycles (ExpB: 1.181, CI: 1.138-1.226, p<0.001). The ROC curve analysis demonstrated that the implantation rate in the oocyte donor has a strong predictive value for pregnancy success in the oocyte recipient (area under the curve: 0.98, CI: 0.95-0.99, p<0.001). Pregnancy in oocyte donors and recipients were highly associated (ExpB: 54.6, CI: 28.1-105.8, p<0.001), regardless of the oocyte recipient’s age. In oocyte recipients, the high-quality embryos rates on days 2 (ExpB: 3.397, CI: 1.635-7.054, p=0.001) and 3 (ExpB: 6.629, CI: 1.185-37.092, p=0.031), and blastocyst development rates (ExpB: 2.331, CI: 1.086-5.001, p=0.030) were positively associated with pregnancy outcome.

Conclusion

The strong association in pregnancy success between donors and recipients, and the lack of correlation between donor characteristics and cycles’ outcomes, demonstrate the power of oocyte quality on the success of ICSI treatment.

Effect of oocyte donor stimulation on recipient outcomes: data from a US national donor oocyte bank

STUDY QUESTION

How does ovarian stimulation in an oocyte donor affect the IVF cycle and obstetric outcomes in recipients?

SUMMARY ANSWER

Higher donor oocyte yields may affect the proportion of usable embryos but do not affect live birth delivery rate or obstetric outcomes in oocyte recipients.

WHAT IS KNOWN ALREADY

In autologous oocyte fresh IVF cycles, the highest live birth delivery rates occur when ~15-25 oocytes are retrieved, with a decline thereafter, perhaps due to the hormone milieu, with super-physiologic estrogen levels. There are scant data in donor oocyte cycles, wherein the oocyte environment is separated from the uterine environment.

STUDY DESIGN, SIZE, DURATION

This was a retrospective cohort study from 2008 to 2015 of 350 oocyte donors who underwent a total of 553 ovarian stimulations and oocyte retrievals. The oocytes were vitrified and then distributed to 989 recipients who had 1745 embryo transfers. The primary outcome was live birth delivery rate, defined as the number of deliveries that resulted in at least one live birth per embryo transfer cycle.

PARTICIPANTS/MATERIALS, SETTING, METHODS

The study included oocyte donors and recipients at a donor oocyte bank, in collaboration with an academic reproductive endocrinology division. Donors with polycystic ovary syndrome and recipients who used gestational carriers were excluded. The donors all underwent conventional ovarian stimulation using antagonist protocols. None of the embryos underwent pre-implantation genetic testing. The average (mean) number of embryos transferred to recipients was 1.4 (range 1-3).

MAIN RESULTS AND THE ROLE OF CHANCE

Per ovarian stimulation cycle, the median number of oocytes retrieved was 30 (range: 9-95). Among the 1745 embryo transfer cycles, 856 of the cycles resulted in a live birth (49.1%). There were no associations between donor oocyte yield and probability of live birth, adjusting for donor age, BMI, race/ethnicity and retrieval year. The results were similar when analyzing by mature oocytes. Although donors with more oocytes retrieved had a higher number of developed embryos overall, there was a relatively lower percentage of usable embryos per oocyte warmed following fertilization and culture. In our model for the average donor in the data set, holding all variables constant, for each additional five oocytes retrieved, there was a 4% (95% CI 1%, 7%) lower odds of fertilization and 5% (95% CI 2%, 7%) lower odds of having a usable embryo per oocyte warmed. There were no associations between donor oocyte yield and risk of preterm delivery (<37 weeks gestation) and low birthweight (<2500 g) among singleton infants.

LIMITATIONS, REASONS FOR CAUTION

Ovarian stimulation was exclusively performed in oocyte donors. This was a retrospective study design, and we were therefore unable to ensure proportional exposure groups. These findings may not generalizable to older or less healthy women who may be vitrifying oocytes for planned fertility delay. There remain significant risks to aggressive ovarian stimulation, including ovarian hyperstimulation. In addition, long-term health outcomes of extreme ovarian stimulation are lacking. Lastly, we did not collect progesterone levels and are unable to evaluate the impact of rising progesterone on outcomes.

WIDER IMPLICATIONS OF THE FINDINGS

Live birth delivery rates remain high with varying amounts of oocytes retrieved in this donor oocyte model. In a vitrified oocyte bank setting, where oocytes are typically sent as a limited number cohort, recipients are not affected by oocyte yields.

STUDY FUNDING/COMPETING INTEREST(S)

Additional REDCap grant support at Emory was provided through UL1 TR000424. Dr. Audrey Gaskins was supported in part by a career development award from the NIEHS (R00ES026648).

Obesity and Reproduction

OBJECTIVE

To provide a comprehensive review and evidence-based recommendations for the delivery of fertility care to women with obesity.

OUTCOMES

The impact of obesity on fertility, fertility treatments, and both short and long-term maternal fetal outcomes was carefully considered.

EVIDENCE

Published literature was reviewed through searches of MEDLINE and CINAHL using appropriate vocabulary and key words. Results included systematic reviews, clinical trials, observational studies, clinical practice guidelines, and expert opinions.

VALUES

The Canadian Fertility & Andrology Society (CFAS) is a multidisciplinary, national non-profit society that serves as the voice of reproductive specialists, scientists, and allied health professionals working in the field of assisted reproduction in Canada. The evidence obtained for this guideline was reviewed and evaluated by the Clinical Practice Guideline (CPG) Committee of the CFAS under the leadership of the principal authors.

BENEFITS, HARMS, AND COSTS

The implementation of these recommendations should assist clinicians and other health care providers in counselling and providing reproductive care to women with obesity.

VALIDATION

This guideline and its recommendations have been reviewed and approved by the membership, the CPG Committee and the Board of Directors of the CFAS.

SPONSORS

Canadian Fertility & Andrology Society.

RECOMMENDATIONS

Twenty-one evidence based recommendations are provided. These recommendations specifically evaluate the impact of obesity on natural fertility, fertility treatments, and maternal-fetal outcomes. Strategies to lose weight and BMI cut-offs are also addressed.

Effect of class III and class IV obesity on oocyte retrieval complications and outcomes

OBJECTIVE

To assess the effect of class III (body mass index [BMI] 40-49.9 kg/m²) and class IV obesity (BMI ≥ 50 kg/m²) on oocyte retrieval complications and outcomes.

DESIGN

Cohort study.

SETTING

Academic center.

PATIENT(S)

Women who underwent an oocyte retrieval from January 1, 2012 to May 31, 2017. Women with BMI ≥ 40 kg/m² (n = 144) were age-matched to women with BMI <25, 25-29.9, 30-34.9, and 35-39.9 kg/m² (n = 1,016).

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Anesthetic and procedural outcomes during oocyte retrieval.

RESULT(S)

Overall, 1,924 of 1,947 oocyte retrievals (98.8%) were performed under total intravenous anesthesia. No patients with BMI ≥ 40 kg/m² required intraoperative conversion to endotracheal intubation or hospital admission. Two patients (0.8%) with BMI ≥ 40 kg/m² required a laryngeal mask airway intraoperatively owing to oxygen desaturation. An oral/nasal airway was used to resolve oxygen desaturation in 16 patients (6.25%) with BMI ≥ 40 kg/m², compared with in 17 patients (1.0%) with BMI < 40 kg/m². As BMI increased, a statistically significant increase in propofol dose, fentanyl dose, and procedure time was observed. Eighteen patients (7.0%) with BMI ≥ 40 kg/m² underwent a transabdominal retrieval, compared with 15 (0.9%) with BMI < 40 kg/m².

CONCLUSION(S)

Serious intraoperative and postoperative complications were uncommon across all BMI groups, though minor complications were more common with class III and class IV obesity. These patients were also more likely to require higher doses of propofol and fentanyl, have longer oocyte retrievals, and require a transabdominal retrieval. Overall, oocyte retrieval can be safely performed as an outpatient procedure in women with class III and class IV obesity.