Cimetidine in labour: absence of adverse effect on the high-risk fetus.

In a prospective randomized trial, 36 women received cimetidine and 32 magnesium trisilicate mixture BP as antacid therapy every 2 h in labour. The women belonged to a high-risk category and the infants born were less than 36 weeks gestation, or less than 2000 g birthweight or otherwise in jeopardy because of severe maternal pre-eclampsia or diabetes. Measurements of a wide range of haematological and biochemical variables revealed no differences between the two groups of babies. The frequency of complications found in the infants was similar, although infants born to the women who received magnesium trisilicate required oxygen therapy for a longer period. Cimetidine did not appear to affect the development of gastric acidity, or to increase bacterial colonization of the gastrointestinal tract in the infant.