The presence or absence of fetal breathing movements predicts the outcome of preterm labour.

54 patients admitted to hospital in labour before the 34th week of pregnancy had real-time ultrasonography to establish the presence or absence of fetal breathing movements. In 19 of 20 pregnancies with no detectable fetal breathing, delivery occurred within 48 h whereas in 25 of 34 with fetal breathing on admission, pregnancy continued for a week or more; of the remaining 9, 7 had had spontaneous rupture of the membranes (with amnionitis in 4). If the presence of fetal breathing identifies cases in which preterm labour will subside spontaneously, this sign should be of value both in trials of treatment and in clinical management.