Parental pre-pregnancy body mass index and risk of low birth weight in offspring: A prospective cohort study in central China

Saturation effects of pre-pregnancy BMI on infant birth weight in Jiangxi Province, China: a retrospective study

There were limited analyses on relationship between body mass index (BMI) pre-pregnancy, as well as birth weight. Research aimed to examine the relation between these two, as well as low birth weight (LBW) risk in Jiangxi Province, China. A total of 1193 pregnant subjects from Jiangxi Province, China were enrolled in the final analysis. Standardized questionnaires were administered to the women during childbirth, newborns' medical information was obtained from hospital records. Pre-pregnancy BMI was categorized into underweight, normal, overweight, and obese groups. Multivariate linear regression models were employed to assess connection between pre-pregnancy BMI, birth weight. We utilized generalized additive model and fitted smoothing curve (penalized spline method) to examine relationship between pre-pregnancy BMI and birth weight, as well as LBW risk. The incidence of LBW was 12.1%, with average pre-pregnancy BMI of 20.9 ± 2.5 kg/m2. The smoothing curve revealed an L-shaped association between pre-pregnancy BMI, birth weight and LBW risk. The curve indicated that as pre-pregnancy BMI increased, LBW risk initially decreased and then plateaued, while birth weight initially escalated and then plateaued. The inflection point for pre-pregnancy BMI was identified as 22 kg/m2. On the left side of inflection point, β (95% CI) for birth weight was 0.04 (0.02, 0.07), and ORs (95% CIs) for LBW risk were 0.78 (0.69, 0.89), on the right side the corresponding values were - 0.00 (-0.03, 0.03) and 1.02 (0.88, 1.19), respectively. All the outcomes presented to be similar in various subgroups. Within a specific range (BMI<22 kg/m2), the correlation between pre-pregnancy BMI and birth weight is statistically significant. This research indicated pre-pregnancy BMI demonstrates a saturation effect on birth weight and LBW risk among Jiangxi Province population.

Association between Pre-pregnancy BMI and Pregnancy Outcomes in Women with Gestational Diabetes: A Retrospective Cohort Study

Background & Objective

The specific influence of the pre-pregnancy body mass index (PPBMI) on women with gestational diabetes mellitus (GDM) is unclear. Our objective was to investigate how PPBMI categories affect pregnancy and neonatal outcomes in women with GDM.

Methods

A retrospective cohort study was conducted using data from patients attending the Fujian Maternity and Child Health Hospital (Fuzhou, China) from 2021 to 2023. The participant records were stratified into four groups according to their BMI values: underweight, normal-weight, overweight, and obese. The pregnancy and neonatal outcomes for these BMI categories were analyzed using multivariable logistic regression.

Results

The study included data from 2,909 pregnant women diagnosed with GDM. Underweight women with GDM showed significantly lower risks of pregnancy-induced hypertension (PIH) (adjusted OR, 0.26) and cesarean sections (adjusted OR, 0.55) but higher risks of low body weight (LBW) infants (adjusted OR, 3.40). Overweight and obese women experienced higher risks of PIH (adjusted OR, 2.96), cesarean sections (adjusted OR, 1.62), and macrosomia (adjusted OR, 1.43).

Conclusion

PPBMIs significantly impact pregnancy outcomes in women with GDM. Both underweight and overweight/obese categories are associated with adverse outcomes, highlighting the need for pre-pregnancy counseling and interventions to achieve and maintain a healthy BMI.

Lower ERVW-1 and higher VEGF, FLT-1 and HIF-1 gene expression in placentae of low birth babies from Indonesia

INTRODUCTION

Poor placental angiogenesis is associated with several pregnancy complications including fetal growth restriction (FGR), which causes low birth weight (LBW) babies to have a high risk of growth disorders and metabolic disorders in adulthood. Recent research using syncytin knock-out mice showed significant disruption in the growth of placental vascularization. Syncytin-1 which encoded by ERVW-1 gene, is proposed to have a role in placental angiogenesis, but its relationship with other proangiogenic factors such as vascular endothelial growth factor (VEGF) in the placenta of LBW babies has not yet been determined. By knowing the mechanisms of FGR, more proactive preventive and therapeutic measures can be taken in the future. This study aimed to determine the expression of ERVW-1, proangiogenic gene VEGF and its receptor (FLT-1), and hypoxia inducible factor-1 (HIF-1) in LBW placentas, and investigate the relationship between these genes' expression in the placenta of LBW babies.

METHODS

Total RNA was extracted from placental tissue. Total RNA is used as a cDNA synthesis template, followed by qRT-PCR. Correlations of ERVW-1, VEGF, FLT-1 and HIF-1 genes' expression were analyzed by linear regression.

RESULTS

The age and body mass index of mothers with LBW and normal birth weight (NBW) babies were not significantly different. ERVW-1 expression in LBW placentas was lower than in NBW placentas, but VEGF, FLT-1 and HIF-1 expressions were higher. ERVW-1 was negatively correlated with HIF-1 and VEGF.

DISCUSSION

Low expression of ERVW-1 in the placenta of LBW babies may result in impaired placental angiogenesis and possibly lead to hypoxia.

[Factors influencing the occurrence of small for gestational age at different degrees]

OBJECTIVES

To investigate the factors influencing the occurrence of small for gestational age (SGA) at different degrees and provide a basis for early identification of severe SGA cases.

METHODS

Neonatal and maternal prenatal information were retrospectively collected from January 2018 to December 2022 at Peking University People's Hospital. The neonates were divided into three groups: severe SGA group (birth weight below the 3rd percentile for gestational age and sex), mild SGA group (birth weight ≥3rd percentile and <10th percentile), and non-SGA group (birth weight ≥10th percentile). An ordered multinomial logistic regression model was used to analyze the factors influencing the occurrence of SGA at different degrees.

RESULTS

A total of 14 821 neonates were included, including 258 cases (1.74%) in the severe SGA group, 902 cases (6.09%) in the mild SGA group, and 13 661 cases (92.17%) in the non-SGA group. The proportions of preterm births and stillbirths were higher in the severe SGA group compared to the mild SGA and non-SGA groups (P<0.0125). The proportion of neonatal asphyxia was higher in both the severe SGA and mild SGA groups compared to the non-SGA group (P<0.0125). Ordered multinomial logistic regression analysis showed that maternal pre-pregnancy underweight (OR=1.838), maternal pre-pregnancy obesity (OR=3.024), in vitro fertilization-embryo transfer (OR=2.649), preeclampsia (OR=1.743), connective tissue disease during pregnancy (OR=1.795), nuchal cord (OR=1.213), oligohydramnios (OR=1.848), and intrauterine growth restriction (OR=27.691) were all associated with a higher risk of severe SGA (P<0.05). Maternal parity as a multipara (OR=0.457) was associated with a lower likelihood of severe SGA (P<0.05).

CONCLUSIONS

Maternal pre-pregnancy underweight, maternal pre-pregnancy obesity, in vitro fertilization-embryo transfer, preeclampsia, connective tissue disease during pregnancy, oligohydramnios, nuchal cord, and intrauterine growth restriction are closely related to the occurrence of more severe SGA. Maternal parity as a multipara acts as a protective factor against the occurrence of severe SGA.

Paternal preconception modifiable risk factors for adverse pregnancy and offspring outcomes: a review of contemporary evidence from observational studies

BACKGROUND

The preconception period represents transgenerational opportunities to optimize modifiable risk factors associated with both short and long-term adverse health outcomes for women, men, and children. As such, preconception care is recommended to couples during this time to enable them to optimise their health in preparation for pregnancy. Historically, preconception research predominately focuses on maternal modifiable risks and health behaviours associated with pregnancy and offspring outcomes; limited attention has been given to inform paternal preconception health risks and outcomes. This systematic review aims to advance paternal preconception research by synthesising the current evidence on modifiable paternal preconception health behaviours and risk factors to identify associations with pregnancy and/or offspring outcomes.

METHODS

Medline, Embase, Maternity and Infant care, CINAHL, PsycINFO, Scopus, and ISI Proceedings were searched on the 5^th of January 2023, a date limit was set [2012-2023] in each database. A Google Scholar search was also conducted identifying all other relevant papers. Studies were included if they were observational, reporting associations of modifiable risk factors in the preconception period among males (e.g., identified as reproductive partners of pregnant women and/or fathers of offspring for which outcomes were reported) with adverse pregnancy and offspring outcomes. Study quality was assessed using the Newcastle-Ottawa Scale. Exposure and outcome heterogeneity precluded meta-analysis, and results were summarised in tables.

RESULTS

This review identified 56 cohort and nine case control studies. Studies reported on a range of risk factors and/or health behaviours including paternal body composition (n = 25), alcohol intake (n = 6), cannabis use (n = 5), physical activity (n = 2), smoking (n = 20), stress (n = 3) and nutrition (n = 13). Outcomes included fecundability, IVF/ISCI live birth, offspring weight, body composition/BMI, asthma, lung function, leukemia, preterm birth, and behavioural issues. Despite the limited number of studies and substantial heterogeneity in reporting, results of studies assessed as good quality showed that paternal smoking may increase the risk of birth defects and higher paternal BMI was associated with higher offspring birthweight.

CONCLUSION

The current evidence demonstrates a role of paternal preconception health in influencing outcomes related to pregnancy success and offspring health. The evidence is however limited and heterogenous, and further high-quality research is needed to inform clinical preconception care guidelines to support men and couples to prepare for a health pregnancy and child.