The Risk Factors of Low Birth Weight Infants in the Northern Part of Thailand
Chiang Mai Low Birth Weight Study Group*
Affiliation : * Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand
Background : The incidence of low birth weight (LBW) in Chiang Mai University Hospital was high.
Objective : Determined the incidence and risk factors of low birth weight infants.
Material and Method: The present study included pregnant women between 1989 and 1990 who attended the antenatal
clinics (ANC) having a gestational age less than or equal to 24 weeks. During that period, up to delivery, clinical and other
potential data namely demographic and biomedical factors, maternal status, socioeconomic factors, and nutritional factors
were included. The birth weight at birth less than 2,500 gm was considered LBW.
Results : Two thousand one hundred eighty four pregnant subjects who delivered live born and were still eligible, were used
for analysis in the present study. The incidence of LBW was 9.2% (201/2,184). Women with body mass index (BMI) at first
antenatal clinics (ANC) less than 18.5 Kg/m2 and weight gain during the second trimester less than 300 grams/week was the
strongest independent risk factor for LBW (odds ratio 11.25, 95% confidence interval (CI) 5.77-21.94). The number of
antenatal care less than 4, monilial vaginitis, the infestation of hookworm and strongyloides, and pregnancy-induced
hypertension were independent risk factors (odds ratio 11.04, 3.14, 4.93 and 4.02 respectively).
Conclusion : The present study showed that low initial BMI, low weight gain in the second trimester, and low attendance at
ANC are associated to the occurrence of LBW. The development of a scoring system for detecting high-risk of LBW in
pregnant women based on a combination of antenatal factors should be pursued.
Keywords : Low birth weight, Maternal, Pregnancy, Risk factors, Thais
