Effect of the Interaction Between Pre-pregnancy Body Mass Index and Fresh/Frozen Embryo Transfer on Perinatal Outcomes of Assisted Reproductive Technology-Conceived Singletons: A Retrospective Cohort Study

Pregnancy following assisted reproductive technology in morbidly obese patients: assessment of feto-maternal outcomes

PURPOSE

To examine feto-maternal characteristics and outcomes of morbidly obese pregnant patients who conceived with assisted reproductive technology (ART).

METHODS

This cross-sectional study queried the Healthcare Cost and Utilization Project's National Inpatient Sample. Study population was 48,365 patients with ART pregnancy from January 2012 to September 2015, including non-obesity (n = 45,125, 93.3%), class I-II obesity (n = 2445, 5.1%), and class III obesity (n = 795, 1.6%). Severe maternal morbidity at delivery per the Centers for Disease and Control Prevention definition was assessed with multivariable binary logistic regression model.

RESULTS

Patients in the class III obesity group were more likely to have a hypertensive disorder (adjusted-odds ratio (aOR) 3.03, 95% confidence interval (CI) 2.61-3.52), diabetes mellitus (aOR 3.08, 95%CI 2.64-3.60), large for gestational age neonate (aOR 3.57, 95%CI 2.77-4.60), and intrauterine fetal demise (aOR 2.03, 95%CI 1.05-3.94) compared to those in the non-obesity group. Increased risks of hypertensive disease (aOR 1.35, 95%CI 1.14-1.60) and diabetes mellitus (aOR 1.39, 95%CI 1.17-1.66) in the class III obesity group remained robust even compared to the class I-II obesity group. After controlling for priori selected clinical, pregnancy, and delivery factors, patients with class III obesity were 70% more likely to have severe maternal morbidity at delivery compared to non-obese patients (8.2% vs 4.4%, aOR 1.70, 95%CI 1.30-2.22) whereas those with class I-II obesity were not (4.1% vs 4.4%, aOR 0.87, 95%CI 0.70-1.08).

CONCLUSIONS

The results of this national-level analysis in the United States suggested that morbidly obese pregnant patients conceived with ART have increased risks of adverse fetal and maternal outcomes.

The effect of female body mass index on cumulative live birth rate in women undergoing in vitro fertilization according to age

The aim of this study was to explore the impact of female body mass index (BMI) on cumulative live birth rates (CLBR) in patients treated with in vitro fertilization (IVF) and embryo transfer. A total of 2377 patients who visited the Reproductive Medical Center, Luoyang Maternal and Child Health Hospital from January 2015 to December 2021. The patients underwent the first IVF cycles. According to female BMI, patients were divided into 3 groups, group A: BMI ≤ 18.5 kg/m2 (underweight), group B: BMI: 18.5 to 24.0 kg/m2 (normal), group C: BMI ≥ 24.0 kg/m2 (overweight/obesity). Patient basic parameters and clinical outcomes were compared among these 3 groups. Multivariate logistic regression analysis was used to explore the impact of BMI on CLBR. In all treatment cycles, patients' basic parameters were significantly different among 3 BMI groups. Age of underweight patient was younger than patients in the other 2 groups (28.45 ± 5.32 vs 29.89 ± 5.00 vs 30.74 ± 5.40; P = .000). In addition, number of oocytes retrieved was also significantly higher in group A (11.25 ± 5.97 vs 11.07 ± 5.49 vs 10.52 ± 5.02; P = .000). CLBR in these 3 groups were 66.40%, 65.98%, and 59.14%, respectively. In logistic analysis, overweight/obesity was associated with CLBR in young patients (aOR = 0.822, 95% CI: 0.817-0.957, P = .000). However, in the cycles of older patients, the effect of overweight/obesity on the CLBR was not significant (aOR = 0.986, 95% CI: 0.903-1.027, P > .05). Overweight/obesity is a predictor for CLBR in younger patients (<35 years old), but not in advanced age patients undergoing their first IVF/intracytoplasmic sperm injection treatment cycles.

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.

Impact of maternal body mass index on outcomes of singleton pregnancies after assisted reproductive technology: a 14-year analysis of the US Nationwide Inpatient Sample

BACKGROUND

Obesity is increasing globally, which affects multiple human functions, including reproductive health. Many women with overweight and obesity of child-bearing years are treated with assisted reproductive technology (ART). However, the clinical impact of body mass index (BMI) on pregnancy outcomes after ART remains to be determined. Therefore, this population-based retrospective cohort study aimed to assess whether and how higher BMI affects singleton pregnancy outcomes.

METHODS

This study used the large nationally representative database of the US National Inpatient Sample (NIS), extracting data of women with singleton pregnancies who had received ART from 2005 to 2018. Diagnostic codes of the International Classification of Diseases, Ninth and Tenth edition (ICD-9 and ICD-10) were used to identify females admitted to US hospitals with delivery-related discharge diagnoses or procedures and secondary diagnostic codes for ART, including in vitro fertilization. The included women were further categorized into three groups based on BMI values < 30, 30-39, and ≥ 40 kg/m². Univariate and multivariable regression analysis were conducted to assess the associations between study variables and maternal and fetal outcomes.

RESULTS

Data of totally 17,048 women were included in the analysis, which represented a population of 84,851 women in the US. Number of women in the three BMI groups were 15, 878 (BMI < 30 kg/m²), 653 (BMI 30-39 kg/m²), and 517 (BMI ≥ 40 kg/m²), respectively. The multivariable regression analysis revealed that, compared to BMI < 30 kg/m², BMI 30-39 kg/m² was significantly associated with increased odds for pre-eclampsia and eclampsia (adjusted OR = 1.76, 95% CI = 1.35, 2.29), gestational diabetes (adjusted OR = 2.25, 95% CI = 1.70, 2.98), and Cesarean delivery (adjusted OR = 1.36, 95% CI = 1.15, 1.60). Further, BMI ≥ 40 kg/m² was associated with greater odds for pre-eclampsia and eclampsia (adjusted OR = 2.25, 95% CI = 1.73, 2.94), gestational diabetes (adjusted OR = 3.64, 95% CI = 2.80, 4.72), disseminated intravascular coagulation (DIC) (adjusted OR = 3.79, 95% CI = 1.47, 9.78), Cesarean delivery (adjusted OR = 1.85, 95% CI = 1.54, 2.23), and hospital stay ≥ 6 days (adjusted OR = 1.60, 95% CI = 1.19, 2.14). However, higher BMI was not significantly associated with greater risk of the fetal outcomes assessed.

CONCLUSIONS

Among US pregnant women who received ART, having a higher BMI level independently increases the risk for adverse maternal outcomes such as pre-eclampsia and eclampsia, gestational diabetes, DIC, longer hospital stays, and higher rates of Cesarean delivery, while risk is not increased for fetal outcomes.

Metabolic status indicators and influencing factors in non-obese, non-centrally obese nonalcoholic fatty liver disease

Non-obese nonalcoholic fatty liver disease (NAFLD) is characterized by metabolic disorders and related complications. This study aimed to provide an integrated description of clinical, metabolic, and influencing factors for a specific category of patients with non-obese NAFLD. A total of 36 participants with body mass index (BMI) < 28 kg/m2 and visceral adipose tissue < 100 cm2 were classified into 2 groups: the non-obese, non-centrally obese control group (n = 17) and non-obese, non-centrally obese NAFLD group (n = 19). Hypertriglyceridemia, impaired fasting glucose, low high-density lipoprotein cholesterol levels, and hypertension were used to determine whether participants were metabolically abnormal. Based on a logistic regression model, odds ratios for the factors influencing NAFLD with 95% confidence intervals were calculated. Insulin resistance (IR) and fasting plasma glucose (FPG) levels were higher in the NAFLD group than in the control group (P < .05). The NAFLD group had a higher metabolic abnormality rate than the healthy control group (36.84% vs 5.88%, P = .044). Correlation analysis showed that IR was positively correlated with FPG and triglyceride (P < .05). BMI was the main influencing factor of NAFLD (regression coefficient β = 0.631; odds ratio = 1.879; 95% confidence interval, 1.233-2.863). NAFLD patients with a BMI < 28 kg/m2 and visceral adipose tissue < 100 cm2 had more apparent IR, higher FPG, and a higher metabolic abnormality rate. IR may be affected by FPG and triglyceride. Even in non-obese and non-centrally obese individuals, BMI should be controlled to avoid NAFLD.

Risk Factors of Preterm Birth and Low Birth Weight in Singletons Conceived Through Frozen Embryo Transfer: A Retrospective Study

Background

The risks of adverse perinatal outcomes in offspring conceived following frozen-thawed embryo transfer (FET) assisted reproductive technology (ART) are inconsistent. The aim of this study was to analyze the risk factors for preterm birth and low birth weight in singletons after FET.

Methods

386 FET cycles was conducted at the Reproductive Medicine Center of Meizhou People's Hospital. The relationship between clinical characteristics and outcomes (term birth and preterm birth, normal birth weight and low birth weight) was analyzed.

Results

The rate of primary infertility, basal FSH and T levels, gestational age, birth weight, and proportion of male fetuses were significantly different in the preterm and full-term groups. Logistic regression analysis showed that high maternal age (≥35 years) (OR 3.652, 95% CI: 1.683-7.925, P=0.001), primary infertility (OR 2.869, 95% CI: 1.461-5.632, P=0.002), low FSH level (<6.215 mIU/mL) (OR 3.272, 95% CI: 1.743-6.144, P<0.001), and hormone replacement therapy (HRT) method (OR 2.780, 95% CI: 1.088-7.100, P=0.033) may increase risk of preterm birth after FET. Gestational age and birth weight were significantly different in fetuses with low birth weight (<2500g, n=38) and normal birth weight (≥2500g and <4000g, n=333). Logistic regression analysis showed that low basal FSH level (<6.215 mIU/mL) (OR 0.425, 95% CI: 0.209-0.865, P=0.018), and HRT method of endometrial preparation for FET (OR 0.272, 95% CI: 0.079-0.934, P=0.039) may reduce the risk of low birth weight after FET.

Conclusion

High maternal age, primary infertility, low FSH level, HRT method of endometrial preparation for FET, and male fetus may increase risk of preterm birth after FET. In addition, primary infertility, low basal FSH level, and HRT method of endometrial preparation may reduce the risk of low birth weight after FET.

Influence of overweight and obesity on perinatal outcomes in assisted reproduction: a retrospective cohort study

Background

In spontaneous pregnancies, maternal weight and gestational diabetes are independent risk factors for macrosomia and large-for-gestational-age newborns. Furthermore, maternal body mass index (BMI) of ≥25 kg/m² is associated with worse neonatal vitality, classified as an Apgar score of < 7 at the fifth minute of life. However, few studies have evaluated the influence of BMI on perinatal outcomes in pregnancies resulting from assisted reproduction. Therefore, this study aimed to analyze whether the perinatal outcomes of assisted reproduction are influenced by BMI.

Methods

This was a retrospective cohort study performed at a reproductive medicine center. Patients undergoing assisted reproduction (2013–2020) were divided into three groups according to their BMI (kg/m²): group 1, < 25; group 2, 25–29.9, and group 3, ≥30. In total, 1753 in vitro fertilization embryo transfer cycles were analyzed. Data were expressed as mean ± standard deviation or frequency (%). The analysis of variance and chi-square test were performed for comparison. To determine the participants and number of cycles for these analyses, generalized estimating equations were used, considering p < 0.05.

Results

In groups 1, 2, and 3, the rates of live birth were 33.5, 32.3, and 29.9% (p = 0.668); preeclampsia were 2.9, 6.1, and 6.3% (p = 0.268); small-for-gestational-age newborns were 23, 23.2, and 21.7% (p = 0.965); macrosomia were 1.9, 0.9, and 2.7% (p = 0.708); Apgar score > 7 at the fifth minute were 97.6, 98.2, and 100% (p = 0.616); and preterm birth were 29.6, 30.1, and 35.1% (p = 0.970), respectively.

Conclusions

In conclusion, although the three groups had similar perinatal outcomes in this study, the study population was too small for conclusive results. The higher the BMI, the lower the chances of clinically relevant LBR and the higher the chances of premature labor and preeclampsia.

Maternal underweight does not adversely affect the outcomes of IVF/ICSI and frozen embryo transfer cycles or early embryo development

OBJECTIVE

To compare assisted reproductive technology (ART) outcomes and preimplantation embryo development between underweight and normal-weight women.

METHODS

This retrospective cohort study included 26 underweight women (body mass index [BMI] < 18.50 kg/m²) and 104 normal-weight women (BMI >20 and <24.9 kg/m²) who underwent a total of 204 in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI) cycles and 358 fresh/frozen embryo transfers (ET) in our institution between January 2016 and December 2018. Statistical analyses compared selected ART outcomes (ovarian stimulation, fertilization, and pregnancy) between both weight groups. Morphokinetic and morphological parameters were also compared between 346 and 1467 embryos of underweight and normal-weight women, respectively.

RESULTS

The mean ± standard deviation age of the underweight and normal-weight women was similar (31.6 ± 4.17 vs 32.4 ± 3.59 years; p = .323). There were no differences in the peak estradiol levels, the number of retrieved oocytes, the number of metaphase II oocytes, and the oocyte maturity rates between the two groups. The IVF/ICSI fertilization rates and the number of embryos suitable for transfer or cryopreservation were similar for both groups. All morphokinetic parameters that were evaluated by means of time-lapse imaging as well as the morphological characteristics were comparable between low and normal BMI categories. There were no significant differences in pregnancy achievement, clinical pregnancy, live births, and miscarriage rates between the suboptimal and optimal weight women.

CONCLUSION

Underweight status has no adverse impacts on the outcomes of IVF/ICSI with either fresh or frozen ET or on preimplantation embryo development and quality.

Association Between Pre-Pregnancy Body Mass Index and Maternal and Neonatal Outcomes of Singleton Pregnancies After Assisted Reproductive Technology

OBJECTIVE

To study the association between pre-pregnancy body mass index (BMI) and adverse maternal and neonatal outcomes of singleton pregnancies after assisted reproductive technology (ART).

METHODS

This hospital-based retrospective cohort study of women with live singleton births through ART in China from January 2015 to August 2020 included 3043 Chinese women. According to the latest BMI classification standard of Asian women, the women included in this study were classified as underweight (BMI <18.5 kg/m²), normal (BMI 18.5 to <23 kg/m²), overweight (BMI 23 to <27.5 kg/m²), and obese (BMI ≥27.5 kg/m²). We compared the risk of adverse outcomes of different pre-pregnancy BMI values of women with singleton pregnancies conceived through ART. We used Logistic regression analysis to estimate the associations between pre-pregnancy BMI and adverse perinatal and neonatal outcomes.

RESULTS

Our findings showed that women who were overweight or obese before pregnancy through ART are more likely to have a cesarean section, gestational diabetes mellitus, gestational hypertension, and preeclampsia, regardless of whether confounding factors are adjusted. Moreover, pre-pregnancy obesity was more associated with a higher risk of these adverse outcomes than pre-pregnancy overweight. In addition, neonates from women who had obesity before pregnancy through ART were more likely to have macrosomia; adjusted odds ratios and 95% confidence intervals were 3.004 (1.693-5.330).

CONCLUSIONS

Our research showed that women who had pre-pregnancy overweight or obesity with singleton pregnancies through ART were more likely to have a cesarean section, gestational diabetes mellitus, gestational hypertension, and preeclampsia. Moreover, neonates from women who had obesity before pregnancy were more likely to have macrosomia.

The Development of Nomograms to Predict Blastulation Rate Following Cycles of In Vitro Fertilization in Patients With Tubal Factor Infertility, Polycystic Ovary Syndrome, or Endometriosis

It is well known that the transfer of embryos at the blastocyst stage is superior to the transfer of embryos at the cleavage stage in many respects. However, the rate of blastocyst formation remains low in clinical practice. To reduce the possibility of wasting embryos and to accurately predict the possibility of blastocyst formation, we constructed a nomogram based on range of clinical characteristics to predict blastocyst formation rates in patients with different types of infertility. We divided patients into three groups based on female etiology: a tubal factor group, a polycystic ovary syndrome group, and an endometriosis group. Multiple logistic regression was used to analyze the relationship between patient characteristics and blastocyst formation. Each group of patients was divided into a training set and a validation set. The training set was used to construct the nomogram, while the validation set was used to test the performance of the model by using discrimination and calibration. The area under the curve (AUC) for the three groups indicated that the models performed fairly and that calibration was acceptable in each model.