Participants selection criteria and sample size
LBW
DRUG ALLERGY
Inclusion criteria were age of 16–35 years derived from date of birth, a gestational age of 12–24 weeks assessed through the last menstrual period (LMP) or the fundal height measurement whenever the LMP date was unknown, presence of fetal movements, willingness to adhere to the study protocol and signed informed consent. Women with a personal history of drug allergy, or using cotrimoxazole chemoprophylaxis for HIV were excluded. Women were also excluded if they had multiple gestations (twins). A sample size of 870 pregnant women was required in order to have 80% power to detect a reduction in LBW incidence from 10 to 5% at the significance level of 0.05 using an uncorrected chi-square statistics and equal sized groups, assuming a 10% loss rate, the sample size was increased to 958 pregnant women.