Association between maternal lifestyle factors and low birth weight in preterm and term births: a case-control study

It has been reported that lifestyle factors may affect birth weight; however, few studies have explored the association between lifestyle factors and low birth weight in preterm and term births in China. The objective of this study was to explore the effect of lifestyle on low birth weight in preterm and term births.

This case-control study was conducted in fourteen hospitals in Jiangmen, Guangdong Province. Data were collected from August 2015 to May 2016 using a standard questionnaire. Data were analysed using logistic regression.

Women who delivered preterm and were physically active (1-3 times per week and ≥ 4 times per week) had reduced odds of having low birth weight babies (aOR = 0.584, 95%CI = 0.394-0.867 and, aOR = 0.516, 95%CI = 0.355-0.752, respectively). Pregnant women who had insufficient gestational weight gain had increased odds of having low birth weight babies (aOR = 2.272, 95%CI = 1.626-3.176). Women exposed to passive smoking had an increased risk of delivering low birth weight infants (aOR = 1.404, 95%CI = 1.057-1.864). Insufficient gestational weight gain and excessive gestational weight gain were both significantly associated with low birth weight (aOR = 1.484, 95%CI = 1.103-1.998 and aOR = 0.369, 95%CI = 0.236-0.577, respectively) for term deliveries. In addition, parity, history of low birth weight, antenatal care and gestational hypertension were significantly associated with the likelihood of low birth weight.

Pregnant women without exercise contraindications should remain physically active. Pregnant women should be aware of the negative effects of smoke and be aware of strategies to protect themselves from passive smoke exposure. Hospitals should inform pregnant women of the importance appropriate gestational weight gain. These recommendations should be put into practice to decrease the prevalence of low birth weight infants.