Fetal breathing movements were examined in 44 women with premature rupture of membranes. All had previously uncomplicated singleton pregnancies (28 to 41 weeks). Of these 44 women, 13 had complications based on later amnionitis/neonatal infection or antepartum fetal distress. Thirty-one normal antepartum patients, matched for gestational age, served as a normal control group. These women had intact membranes and were without any known or suspected maternal, fetal, or neonatal complications. Fetal breathing movements were found in 90% of cases in the control group, compared with 65% in the 31 women with premature rupture of membranes (p less than 0.05). In the group of 13 women with premature rupture of membranes and complications, the incidence of fetal breathing movements was 38%. Therefore, it is possible that the absence of fetal breathing movements can be due to premature rupture of membranes alone. There was a statistically higher incidence of low-birth-weight infants and low Apgar scores in the group of 13 women with premature rupture of membranes and complications compared with the group of 31 women with premature rupture of membranes.