Seventy percent of the annual 32 million low-birth-weight (weight <2.5 kg at birth) neonates globally are born in developing countries (1). In South Asia (which includes India), an estimated 30% of babies are born with low birth-weight (1). Low birth-weight is often used as a proxy indicator for intrauterine growth retardation in developing countries because a valid assessment of gestational age is often not available. In India, one-third of babies born are of low birth-weight (2). Low birth-weight is associated with increased morbidity and mortality, impaired immune function, and poor cognitive development (3) for neonates, infants, and young children. The risk of neonatal deaths among babies weighing 2-2.5 kg at birth was estimated to be four times the rate in neonates with birth-weight of 2.5-3 kg and 10 times higher than in neonates weighing 3-3.5 kg (3). Of all the neonatal deaths in India, an estimated 81% occur among low birth-weight neonates, and a high proportion occurs among pre-term babies (2).
Bacterial vaginosis has been consistently associated with a risk of spontaneous pre-term birth in the West (47). In two randomized trials involving women at high risk of pre-term birth, treatment of bacterial vaginosis with metronidazole either alone or in combination with erythromycin resulted in substantial reduction in rates of spontaneous pre-term births (8,9). Furthermore, undiagnosed and untreated bacteriuria in pregnant women may also increase the risk of low birth-weight and perinatal deaths (10). The prevalence of reproductive tract infections (RTIs) is high among Indian women of reproductive age (11,12), particularly among the lower socioeconomic groups. In developing countries, large maternity hospitals serving the urban poor work beyond capacity and under extreme resource constraints. Given these factors and reported benefit (8,9), the health practitioners in India commonly give antimicrobials to pregnant women to treat putative bacterial vaginosis for improving pregnancy outcome, particularly birth-weight. However, such an approach to treatment has not been evaluated.
We hypothesize that treating poor urban pregnant women with antimicrobials for putative RTIs and UTIs routinely will reduce the rate of low birth-weight by prolonging the duration of pregnancy and by improving intrauterine nutrition of the foetus. In a randomized controlled trial, we evaluated the role of routine antimicrobial therapy during the second trimester of pregnancy on birth-weight and gestation in urban poor pregnant women in the metropolitan city of Kolkata, India. The rate of low birth-weight is known to be high in this patient population.
MATERIALS AND METHODS
Study population and intervention
The study was conducted among pregnant women in their second trimester as ascertained by the history of last menstrual period (between 14 and 24 weeks), not suffering from any significant medical, surgical, obstetric or gynaecological disorders and attending the antenatal clinic of a government hospital in Kolkata, India, that serves the urban poor. Women likely to deliver at this hospital were enrolled in the study after obtaining informed written consents from the pregnant women. Recruitment took place during February-July 2001. The subjects who stayed at a distance where home-visits, if necessary, would be difficult were excluded. Detailed history, anthropometric measurements, and clinical examinations of the subjects were recorded in a pre-tested data form, and the following investigations were done at recruitment. Urine was tested by the dipstick method for protein, nitrites, and leucocytes, which are indicators of infection. The test results were not used for inclusion of subjects in the study. Blood was tested for haemoglobin and haematocrit, Venereal Disease Research Laboratory test for syphilis, C-reactive protein, blood group, and one-hour post-prandial blood glucose after taking 75 g of glucose. …