Inadequate Gestational Weight Gain and Exposure to Second-Hand Smoke during Pregnancy Increase the Risk of Low Birth Weight: A Cross-Sectional Study among Full-Term Infants

Despite the advancement of the healthcare system, low birth weight (LBW) remains as one of the leading causes of under-five mortality. This cross-sectional study aimed to determine the prevalence of LBW and its associated factors among 483 third trimester pregnant women recruited from six selected public health clinics in the Federal Territory of Kuala Lumpur and the state of Selangor, Malaysia. Pregnant women were interviewed for information on socio-demographic characteristics, smoking behaviour, and second-hand smoke (SHS) exposure at home and in the workplace. Information on the obstetrical history and prenatal care visits history were retrieved from the maternal medical records, while infant's birth outcomes were retrieved from infant medical records. The prevalence of LBW (<2.5 kg) in infants was 10.4%, with a mean birth weight of 3.0 [standard deviation (SD) 0.4] kg. Results from the multivariable logistic regression model showed that inadequate weight gained during pregnancy [odds ratio (OR) = 2.41, 95% confidence interval (CI) = 1.18-4.90] and exposure to SHS at home (OR = 1.92, 95% CI = 1.03-3.55) were significantly associated with LBW. In conclusion, pregnant women should monitor their rate of weight gain throughout pregnancy and avoid SHS exposure at home to reduce the risk of delivering LBW infants.