Early pregnancy body mass index and spontaneous preterm birth in Northwest Russia: a registry-based study

Abstract

BackgroundInternational studies on the association between maternal body mass index (BMI) and spontaneous preterm birth (PTB) yield controversial results warranting large studies from other settings. The aim of this article was to study association between maternal early pregnancy BMI and the risk of spontaneous PTB in Murmansk County (MC), Northwest Russia.MethodsThis is a registry-based cohort study. All women with singleton pregnancies registered at antenatal clinics during the first 12 weeks of gestation and who delivered in MC between January, 1st 2006 and December, 31st 2011 comprised the study base (n = 29,709). All women were categorized by BMI into four groups: underweight (<18.5 kg/m2), normal (18.5–24.9 kg/m2), overweight (25.0–29.9 kg/m2), and obese (≥30.0 kg/m2). Multivariable logistic regression was used to study associations between maternal BMI and PTB (<37 weeks) and very preterm birth (VPTB) (<32 weeks) adjusted for socio-economic factors, biological and lifestyle characteristics.ResultsThe prevalence of underweight, overweight and obesity were 7.1% (95% CI: 6.8-7.4), 18.3% (95% CI: 17.8-18.7) and 7.1% (95% CI: 6.8-7.4), respectively. Altogether, 5.5% (95% CI: 5.3-5.8) of the births were PTB and 0.8% (95% CI: 0.7-0.9) were VPTB. After adjustment, both underweight (OR = 1.25, 95% CI: 1.03-1.50), overweight (OR = 1.10, 95% CI: 0.97-1.26) and obese (OR = 1.31, 95% CI: 1.08-1.57) women were more likely to deliver preterm. VPTB was associated with overweight (OR = 1.47, 95% CI: 1.056-2.03) and obesity (OR = 1.63, 95% CI: 1.02-2.60).ConclusionThe findings demonstrate a J-shaped association between first trimester maternal BMI and spontaneous PTB and VPTB with increased risk among underweight, overweight and obese women.

Maternal Risk Factors for Preterm Birth in Murmansk County, Russia: A Registry‐Based Study

“…In the city of Monchegorsk (Murmansk County), the prevalence of PTB is higher in unmarried women, for women with prior PTB and smokers . In a recent paper on BMI among the current study population, maternal obesity was associated with both very and moderate spontaneous PTBs; this risk also increased for underweight mothers . To date, studies on GA‐dependent multiple risk factors of PTB in Russia have not been done.…”

“…We found no evidence of increased risk of very and extremely PTB in underweight women, and only a small increase in the risk of moderate‐to‐late PTB. Nevertheless, many studies demonstrate an association between low maternal weight and spontaneous PTB …”

“…22 In a recent paper on BMI among the current study population, maternal obesity was associated with both very and moderate spontaneous PTBs; this risk also increased for underweight mothers. 23 To date, studies on GA-dependent multiple risk factors of PTB in Russia have not been done. Clearly, PTB is a multi-causal process that involves the interaction of multiple factors.…”

Social correlates of term small for gestational age babies in a Russian Arctic setting

“…The Registry contains socio-demographic information, data about the index pregnancy and mother's pre-pregnancy health, delivery and infant's health. A set of previously published studies describes MCBR in detail (32–34). …”

A Comparison of the Effective Factors of Preterm Birth Versus Low Birth Weight in Southern Iran Using Artificial Neural Network

“…According to the data of World Health Organization (WHO) and World Bank, in 2002 wars had been among the first ten reasons which killed the most and caused disabilities. Civil losses are at the rate of 90% within all losses (1). War has many negative effects on human health.…”