Effect of pregravid obesity on perinatal outcomes in singleton pregnancies following in vitro fertilization and the weight-loss goals to reduce the risks of poor pregnancy outcomes: A retrospective cohort study

Systematic review and meta-analysis of birth outcomes in women with polycystic ovary syndrome

It is unclear whether polycystic ovary syndrome (PCOS) is an independent risk factor for adverse birth outcomes in the offspring of affected women. Here, we investigate the association of PCOS with birth outcomes in the offspring of women with PCOS overall and by potential confounders. This systematic review and meta-analysis included 73 studies and 92,881 offspring of women with and without PCOS from inception until 13th July 2022. We report that mothers with PCOS are younger and have higher body mass index (BMI) around conception and have greater gestational weight gain. The odds of preterm birth, fetal growth restriction and low birth weight are higher and mean birthweight is lower in PCOS of which a lower mean birthweight and a higher small for gestational age are probably independent of BMI. This work informed the recommendations from the 2023 international evidence-based guideline for the assessment and management of polycystic ovary syndrome, emphasizing that PCOS status should be captured at pregnancy to identify risk and improve birth outcomes in the offspring.

Systematic review and meta-analysis of pregnancy outcomes in women with polycystic ovary syndrome

Screening for polycystic ovary syndrome (PCOS) in antenatal care is inadequate, largely owing to the lack of clarity around whether PCOS is an independent risk factor for pregnancy complications. This systematic review and meta-analysis include 104 studies and 106,690 pregnancies in women with and without PCOS from inception until 13th July 2022. We report that women with PCOS are younger and have higher body mass index (BMI) around conception and have greater gestational weight gain. The odds of miscarriage, gestational diabetes mellitus, gestational hypertension, pre-eclampsia and cesarean section are higher in women with PCOS. The increased odds of adverse outcomes in PCOS remain significant when age and BMI are matched and when analyses are restricted to high-quality studies. This work informed the recommendations from the 2023 international evidence-based guideline for the assessment and management of polycystic ovary syndrome, emphasizing that PCOS status should be captured in all women who are planning to, or have recently become pregnant to facilitate prevention of adverse outcomes and improve pregnancy outcomes.

Pre-gravid body mass index is associated with a higher risk of gestational hypertension in singleton pregnancy following frozen-thawed embryo transfer

Introduction

Although it is well-known that obesity increases the risk of gestational hypertension (GH) in both spontaneous and assisted reproductive technology (ART) pregnancies. Recent data show that, in ART pregnancies, frozen-thawed embryo transfer (FET) is associated with an even higher risk of GH compared with fresh transfer. However, the relationship between pre-gravid body mass index (BMI) and GH in FET pregnancies has seldom been reported.

Objective

The aim of this study is to examine the effect of pre-gravid BMI on GH in singleton pregnancy following FET.

Methods

A retrospective cohort study at a tertiary hospital, including a total of 7,502 women who achieved singleton pregnancy after FET, was included. All patients were enrolled only once. On the basis of the BMI definitions of the Working Group on Obesity in China (WGOC) and the World Health Organization, the women were divided into normal BMI, overweight, and obese groups. The main outcome was GH, and the effect of pre-pregnancy BMI on GH was assessed by generalized linear model.

Results

The risk of GH in our study population was 6.15%. According to the BMI definitions of the WGOC, the risk of GH in the obese group (15.55%) was significantly higher than that of the overweight group (8.26%, P < 0.001) and the normal BMI group (4.68%, P < 0.001). Pre-gravid overweight and obesity were associated with higher GH risk (OR, 1.77; 95% CI, 1.41-2.20; P < 0.001; OR, 3.69; 95% CI, 2.77-4.91; P < 0.001). A non-linear relationship between pre-gravid BMI and GH was observed. The risk of GH decreased with pre-gravid BMI level up to the turning point of BMI = 28.6 kg/m2 (OR, 1.16; 95% CI, 1.12-1.21; P < 0.001).

Conclusion

Pre-gravid overweight and obesity are associated with higher GH risk among singleton pregnancy following FET. Before the turning point of BMI = 26.8 kg/m2, the risk of GH may increase 16.4% with each one-unit increment of maternal BMI. Women preparing for FET should maintain a normal BMI to lower the chances of GH.

Risk factors for adverse pregnancy outcomes in Chinese women: a meta-analysis

Objective

This study examined the associated risk factors of adverse pregnancy outcomes among Chinese females and furnished some fundamental principles and recommendations for enhanced prevention of adverse pregnancy and preservation of women's well-being.

Methods

A systematic review was conducted by retrieving the MEDLINE (The National Library of Medicine), Embase, PubMed, and Cochrane databases. The relevant risk factors for adverse pregnancy in Chinese women were retrieved from May 2017 to April 2023. Use Review Manager for data analysis. Calculate the merge effect based on data attributes using mean difference (MD) or odds ratio (or) and 95% confidence interval (CI). The meta-analysis was registered at INPLASY (International Platform of Registered Systematic Review and Meta-analysis Protocols, 202340090).

Results

A total of 15 articles were included, with a total of 946,818 Chinese pregnant women. Moreover, all the literature was scored by the NOS (Newcastle-Ottawa Scale), and all literatures were ≥7 points, which were evaluated as high quality. There are seven risk factors related to adverse pregnancy in Chinese women: parity, pregnancy frequency, education level, smoking, gestational diabetes, gestational weeks, and age. Moreover, the main risk factors for adverse pregnancy are pregnancy frequency, education level, gestational diabetes mellitus, and age.

Conclusion

The pregnancy frequency, education level, gestational diabetes mellitus, and age were significantly associated with the adverse pregnancy in Chinese women, whereas gestational weeks, smoking, and parity had no significant effect on adverse pregnancy.

The impact of weight loss for obese infertile women prior to in vitro fertilization: A retrospective cohort study

Obesity is detrimental to general health and also reproductive health. This study aimed to evaluate whether weight reduction in obese infertile women prior to in vitro fertilization reduces the total gonadotropin dose and improves pregnancy outcomes. This retrospective cohort study was performed at the Jiaxing Maternity and Child Health Care Hospital between January 2017 and January 2022, and 197 women were enrolled. The women were divided into 2 groups according to the weight loss goal of 5%: weight reduction group A (≥weight loss goal of 5%) and control group A ( Collapse

Key Words

• body mass index
• clinical pregnancy rate
• in vitro fertilization
• obese
• weight loss

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MESH Headings

• Child
• Pregnancy
• Female
• Humans
• Infertility, Female
• Retrospective Studies
• Fertilization in Vitro
• Obesity
• Pregnancy Rate
• Live Birth
• Gonadotropins
• Weight Loss

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Grants Collapse

Affiliation(s)

Chunjuan Shen Centre for Reproductive Medicine, Jiaxing University Affiliated Maternity and Child Hospital, Jiaxing Maternity and Child Health Care Hospital, Jiaxing, Zhejiang, China
Weiping Fu Centre for Reproductive Medicine, Jiaxing University Affiliated Maternity and Child Hospital, Jiaxing Maternity and Child Health Care Hospital, Jiaxing, Zhejiang, China
Chunxia Fang Centre for Reproductive Medicine, Jiaxing University Affiliated Maternity and Child Hospital, Jiaxing Maternity and Child Health Care Hospital, Jiaxing, Zhejiang, China
Huan Zhou Traditional Chinese Medicine Department, Jiaxing University Affiliated Maternity and Child Hospital, Jiaxing Maternity and Child Health Care Hospital, Jiaxing, Zhejiang, China
Liping Wang Centre for Reproductive Medicine, Jiaxing University Affiliated Maternity and Child Hospital, Jiaxing Maternity and Child Health Care Hospital, Jiaxing, Zhejiang, China

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Low-dose aspirin in the prevention of pre-eclampsia in China: postpartum hemorrhage in subgroups of women according to their characteristics and potential bleeding risk

BACKGROUND

The APPEC study is a large-population randomized controlled trial in China evaluating the role of low-dose aspirin prophylactic treatment for pre-eclampsia. There was no statistically significant difference in postpartum hemorrhage (PPH) incidence between the aspirin and control groups. This study aimed to evaluate the potential bleeding risk of 100 mg aspirin in high-risk pregnant women and the difference in the incidence of PPH according to maternal characteristics.

METHODS

This is a secondary data analysis of the APPEC study. Platelet counts and coagulation test results were collected at five follow-up visits. Subgroups defined by maternal age (<35 years and ≥35 years), pre-pregnancy body mass index (pre-BMI, <28 kg/m 2 and ≥28 kg/m 2 ), parity, gestational age at enrollment, and medical history, including pre-eclampsia, chronic hypertension, and diabetes mellitus, were analyzed. Logistic regression analysis was used to determine the statistical significance of the difference in the incidence of PPH after aspirin administration in pregnant women in each subgroup. Adjustment using multiple logistic regression models followed these analyses. Binary logistic regression was used to determine the relationship between pre-BMI and PPH.

RESULTS

There was no significant difference between the aspirin and control groups in bleeding risk (3.4% [16/464] vs. 3.0% [13/434], T = 0.147, P  = 0.701). No significant difference was found in the incidence of PPH in total (relative risk  = 1.220, 95% confidence interval [CI] = 0.720-2.067, P  = 0.459; aspirin group vs. control group, 6.5% [30/464] vs. 5.3% [23/434], P  = 0.459) or in subgroup analysis. A significant correlation between pre-BMI and PPH was found in the aspirin group, while in the control group there was no significant correlation (aspirin group, odds ratio [OR] = 1.086, 95% CI = 1.004-1.175, P  = 0.040; control group, OR = 1.060, 95% CI = 0.968-1.161, P  = 0.209).

CONCLUSIONS

A dosage of 100 mg of aspirin per day, initiated from 12 to 20 gestational weeks until 34 weeks of gestation, did not increase the risk of potential bleeding and PPH regardless of the maternal characteristic. In the aspirin group, the positive correlation between BMI and PPH was significant.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT01979627.

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

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

The effect of dietary fiber supplement on prevention of gestational diabetes mellitus in women with pre-pregnancy overweight/obesity: A randomized controlled trial

Objective: To investigate the effect of dietary fiber intake during pregnancy on the prevention of gestational diabetes mellitus (GDM) in women who are overweight/obese prior to pregnancy.

Methods: This randomized controlled trial was conducted in Shanghai General Hospital from June 2021 to March 2022. A total of 98 women who reported BMI≥24 kg/m² prior to pregnancy were recruited before their 20th gestational week, and randomly (simple random allocation) assigned to the fiber supplement group (12 g of dietary fiber power twice daily) and the control group (standard prenatal care) from 20 to 24⁺⁶ gestational weeks. Both groups received nutrition education and dietary advice during the study. GDM diagnosis was performed by an oral glucose tolerance test (OGTT) at 25–28 weeks’ gestation. Data are presented as means with SD, as medians with IQR, or as counts with percentages as appropriate. Comparisons were conducted using a t-test, Mann-Whitney U test, and χ² test, respectively.

Results: The incidence of GDM was significantly reduced in the fiber supplement group compared with the control group: 8.3 vs. 24.0% (χ² = 4.40, p = 0.036). At OGTT, the mean fasting plasma glucose in the fiber supplement group was significantly lower than before the intervention (4.57 ± 0.38 mmol/L vs. 4.41 ± 0.29 mmol/L, p < 0.01) but not in the control group (4.48 ± 0.42 mmol/L vs. 4.37 ± 0.58 mmol/L, p = 0.150). Compared with the control group, the TG and TG/HDL-C ratio levels in the intervention group were significantly higher than those in the control group (2.19 ± 0.54 mmol/L vs. 2.70 ± 0.82 mmol/L and 1.19 ± 0.49 vs.1.63 ± 0.63, respectively, all P＜0.05). The body weight gain was significantly lower in the fiber supplement group than the control group (1.99 ± 1.09 kg vs. 2.53 ± 1.20kg, p = 0.022). None of the women randomized to the fiber supplement group experienced preterm birth (<37 weeks gestation) compared with 12.0% in the control group (p = 0.040). Excessive weight gain (total weight gain >11.5 kg for overweight, and >9.0 kg for obesity) occurred in 46.7% of women in the fiber supplement group compared with 68.0% in the control group (p = 0.035). There were no differences in other maternal and neonatal outcomes.

Conclusion: Increased dietary fiber intake in pregnant women who were overweight/obese prior to pregnancy may reduce the risk of GDM, excessive weight gain, and preterm birth, but it did not improve blood lipids.

Dose-response association between maternal pre-pregnancy bodyweight and gestational diabetes mellitus following ART treatment: a population-based cohort study

BACKGROUND

The impact of maternal pre-pregnancy bodyweight on gestational diabetes mellitus (GDM) following assisted reproductive technology (ART) treatment has been insufficiently investigated. The aim of this study was to investigate the association between maternal pre-pregnancy bodyweight and GDM following ART.

METHODS

From January 2014 to March 2019, this population-based retrospective cohort study included pregnancies achieved by ART treatment in a pregnancy registration database in China. Multivariate regression analysis and restricted cubic splines were used to explore the association between bodyweight and GDM.

RESULTS

A total of 6,598 pregnancies were included. The incidence of GDM was 26.0% (1715/6598). A total of 868 (13.2%) pregnant women were underweight, 665 (10.8%) were overweight, and 145 (2.20%) were obesity. We found a linear dose-response relation between maternal body mass index and GDM by restricted cubic splines, where one unit body mass index increase was associated with the 15% elevated risk of GDM (adjusted odds ratio [OR] 1.15, 95% CI 1.08-1.22). Compared to the normal weight group, maternal underweight was associated with lower risk of GDM (adjusted OR 0.68, 95% CI 0.57-0.82), while increased risk was found for overweight (adjusted OR 1.54 95% CI 1.29-1.84) and obesity (adjusted OR 1.74, 95% CI 1.23-2.47).

CONCLUSIONS

Our study found a linear dose-effect relationship between pre-pregnancy bodyweight and GDM following ART treatment. The findings in this study support the clinical recommendation of advising women with overweight or obesity to lose weight prior to ART treatment.

The incidence of gestational diabetes mellitus among women with polycystic ovary syndrome: a meta-analysis of longitudinal studies

BACKGROUND

Previous studies have shown that polycystic ovary syndrome is a predictor of gestational diabetes mellitus, but we do not know exactly how many polycystic ovary syndrome patients may develop gestational diabetes mellitus. Currently, the incidence of gestational diabetes mellitus among women with polycystic ovary syndrome varies greatly across studies, ranged from 4.12% to 59.50%. Besides, many factors have been found to be related to the incidence of gestational diabetes mellitus among women with polycystic ovary syndrome, but the results among different studies are not consistent. The possible causes of inconsistencies between the current estimates were unclear. This review aimed at exploring the pooled incidence of gestational diabetes mellitus among women with polycystic ovary syndrome, summarizing possible causes of the inconsistencies in the current estimates, try to provide a reference for prevention of gestational diabetes mellitus and polycystic ovary syndrome in the future.

METHODS

Systematic searches of different databases (including EMBASE, Web of Science, MEDLINE, The Cochrane Library, CNKI and PubMed) were conducted for studies published until 31 May 2021. Statistical analyses were performed using R software, the pooled incidence of gestational diabetes mellitus among polycystic ovary syndrome patients was combined using random effects model. Cochrane's "Tool to Assess Risk of Bias in Cohort Studies" was used for quality assessment.

RESULTS

Twenty-two longitudinal studies were included. A total of 24,574 women with polycystic ovary syndrome were identified in the 22 articles, of which 4478 were reported with gestational diabetes mellitus. The pooled incidence of gestational diabetes mellitus among women with polycystic ovary syndrome was 20.64%, with a 95% CI of 14.64% to 28.30%. In the meta-regression model, several variables including age, area, quality score and sample size were suggested as significant sources of heterogeneity, accounted for 77.57% of the heterogeneity across studies.

CONCLUSIONS

Evidence in this review suggests that gestational diabetes mellitus were common among women with polycystic ovary syndrome. More research is needed to found effective interventions for preventing gestational diabetes mellitus among women with polycystic ovary syndrome.

Effect of a 60-day weight reduction intervention prior to IVF/ICSI on perinatal outcomes in overweight or obese infertile women

PURPOSE

The aim of this study was to determine whether a 60-day weight reduction intervention prior to in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI) and a higher weight loss ratio effectively improved perinatal outcomes for infertile overweight or obese women.

METHODS

This was a retrospective cohort study conducted at a university-affiliated fertility center. Two thousand three hundred and eighty-one overweight or obese infertile women who underwent or did not undergo a 60-day weight reduction intervention prior to IVF/ICSI between February 27, 2017 and November 11, 2020 were included in this study. All of these women achieved clinical pregnancy and delivered a single child after assisted reproductive technology (ART). Primary outcomes included neonatal birth weight and the incidence of pregnancy complications, premature delivery, and low birth weight.

RESULTS

The body mass index (BMI), blood glucose concentration, serum insulin level, and homeostasis model assessment of insulin resistance (HOMA-IR) of the intervention group decreased significantly after the weight reduction intervention. Neonatal birth weight was significantly higher in the intervention group (3519.6 g ±484.8 g) than the control group (3406.8 g ± 554.2 g; P < 0.001). There was no significant difference in the incidence of pregnancy complications between the two groups. Linear regression analysis found that the weight reduction intervention prior to IVF/ICSI and lower HOMA-IR at ovulation induction were associated with increased birth weight. As the weight loss ratio increased, the incidence of hypertensive disorders of pregnancy, premature membrane rupture, premature delivery, stillbirth, and low birth weight showed a downward trend.

CONCLUSIONS

A 60-day weight reduction intervention prior to IVF/ICSI may increase neonatal birth weight, reduce maternal blood glucose concentration, and improve maternal insulin resistance in infertile overweight or obese women. This results require to be further verified by prospective randomized controlled trials with a larger sample size.

Predictors of pregnancy after intrauterine insemination in women with polycystic ovary syndrome

Objective

To evaluate the effects of body mass index (BMI) in patients with polycystic ovary syndrome (PCOS) undergoing controlled ovarian stimulation (COS) with intrauterine insemination (IUI).

Methods

This retrospective study evaluated couples with PCOS undergoing COS and IUI. The relationship between cumulative IUI pregnancy outcomes and BMI, treatment cycles, treatment schemes, number of dominant follicles, endometrial thickness, infertility duration and type of infertility was analysed.

Results

The study evaluated 831 IUI cycles in 451 couples with PCOS. Compared with normoweight women, overweight and obese women required more human menopausal gonadotropin (hMG) doses and more days of COS. Gestational diabetes mellitus occurred more frequently in the obese group than in the other BMI groups. The clinical pregnancy and live birth rates in the hMG, clomiphene citrate (CC) + hMG and letrozole (LE) + hMG groups were significantly higher than those in the CC and LE groups. The clinical pregnancy rate was higher in the secondary infertility group compared with the primary infertility group.

Conclusion

Obese women might require more hMG doses and more days of COS to overcome the effects of weight. As BMI increases, the incidence of gestational diabetes might also increase. The number of cycles and type of infertility may have a predictive value for pregnancy outcomes.

Maternal and fetal outcomes during pregnancy and puerperium in obese and overweight pregnant women. A cohort study

PURPOSE

compare incidences of maternal-fetal complications during pregnancy, labor, and early puerperium according to baseline BMI in a consecutive cohort of pregnant women.

METHODS

This retrospective cohort study compares pregnancy outcome indicators by body mass index (BMI) in 1236 pregnant women managed over the period January 2017 to May 2018. Data were collected regarding the personal history (smoking, diabetes and hypertension), obstetrics and BMI (kg/m²) (normoweight 18.5-24.9, overweight 25-29.9, obese ≥ 30).

RESULTS

Of the 1236 women, 354 (28.6%) were overweight and 206 (16.7%) were obese at the start of pregnancy follow-up. Mean age at this time was 33 years (SD 6). Risk factors for a cesarean-section delivery assessed through logistic regression were maternal age (OR 1.05 95% CI 2.06-6.15; p < 0.001) and previous C-section (OR 4.21 95% CI 2.89-6.14; p < 0.001) regardless of BMI. In a propensity score analysis, pregnancy weight gain was found lower in obese vs normoweight (- 2.73 kg 95% CI - 3.74 to - 1.72 p < 0.001), and newborn weight higher in obese vs normoweight women (161.21 g 95% CI 57.94-264.48 p = 0.002). Labor duration and weight gain were reduced in overweight vs normoweight subjects (- 0.72 h 95% CI - 1.27 to - 0.17 p = 0.010 and 0.81 kg 95% CI - 1.50 to - 0.12 p = 0.021, respectively).

CONCLUSIONS

In this cohort, obese women showed higher rates of prenatal complications yet obesity and overweight were not related to worse puerperium outcomes.

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.