Randomly selected parturients with term singleton pregnancies from two different settings, 83 from Mozambique and 90 from Sweden, entered the study. All of them underwent elective cesarean section, which enabled sterile harvesting of amniotic fluid (AF). AF samples were then tested for antibacterial activity (ABA). Background data and nutritional status were compared. Average age was 32.7 and 30.7 years (n.s.), average parity 6.6 and 1.6 (p < 0.0001), average number of antenatal visits 4.9 and 11.6 (p < 0.0001), and average birthweight 3,194 and 3,688 g (p < 0.01), respectively. Body mass index, mid-upper-arm circumference and hemoglobin did not show any significant differences. The average ABA of AF was more than 50% higher in Swedish than in Mozambican specimens (p < 0.0001). Less than one-sixth of MoZambican women reached the average ABA of AF from Swedish women. Bacterial outgrowth delay equal to or above 3 h was encountered in 13% of Mozambican AF as against 61% of Swedish AF (OR 0.10; 95% CI 0.05-0.19). Histopathological examinations of the placenta, nonplacental membranes and umbilical cord showed inflammatory lesions in 29% of the Mozambican parturients and in 13% of Swedish parurients (OR 2.65; 95% 1.00-6.98). It is probable that the lower antibacterial activity in Mozambican AFs reflects an increased vulnerability to ascending genital infections during late pregnancy.