Maternal Risk Factors for Low Birth Weight Infants at Somdetphraphutthalertla Hospital

Abstract

        Low birth weight is a major public health problem. It increases evidences of newborns mortality and morbidity. Furthermore, it leads to impairment of infant development. To determine the maternal risk factors for the occurrence of low birth weight infants at Somdetphraphutthalertla Hospital, Samut Songkhram, a retrospective case-control study was carried out during the period July 1, 2008 - June 31, 2010 in 2,533 registered mothers who had delivered livebirth fetuses at 28 weeks or more gestational age. The sample size was 456, out of which 228 mothers with low birth weight infants (birth weight under 2,500 grams) were selected as cases, 228 mothers of consecutive infants whose birth weight 2,500 grams and above were selected as controls. Mothers with anomalous fetuses were excluded. Delivery and inpatients medical records were extracted and collected. The study was an unmatched case-control on maternal risk factors related to low birth weight infants in the aspects of socio-demographic factors, biological factors and pregnancy factors. Bivariate analysis was employed and an odds ratio with 95% confidence interval calculated to show the strength of association. It was found that maternal educational level in illiterate-primary, height < 150 centimeters, pre-pregnancy weight < 45 kilograms, weight gain during pregnancy < 10 kilograms, body mass index < 20 kilograms /m2, pregnancy induced hypertension, gestational age <37 weeks, premature rupture of membrane, twin pregnancy, and prior delivery of low birth weight or premature baby were significant risks. But not significant for maternal age, gravidity, prenatal care < 4 visits, previous cesarean delivery, history of intrauterine fetal death or abortion, antepartum hemorrhage, maternal anemia (hemoglobin < 11gm%), maternal diseases and smoking. With multiple logistic regression, the variables found most significantly associated with low birth weight were twin pregnancy (adjusted OR 15.554, 95% CI 3.927, 61.609), gestational age <37 weeks (adjusted OR 12.170, 95% CI 6.438, 23.004), pregnancy induced hypertension (adjusted OR 5.468, 95% CI 2.123, 14.083), weight gain during pregnancy < 10 kilograms (adjusted OR 3.571, 95% CI 2.141, 5.958), maternal height < 150 centimeters (adjusted OR 2.377, 95% CI 1.097, 5.153) and body mass index < 20 kilograms/m2(adjusted OR 1.827, 95% CI 1.021, 3.271)

        Programs to improve maternal and child health should promptly focus on all these factors. Progressive surveillance of twin pregnancy, premature labor, pregnancy induced hypertension should be accomplished as well as the promotion of balanced nutritious diet for all pregnant women had been encouraged seriously to minimize the rate of low birth weight newborns and their unpleasant sequelae.

Key words: maternal risk factors, low birth weight, LBW infants