Reservations on the Safety of Oxytocin Nasal Spray in Obstetrics*

Abstract

Summary: 1. Claims for the safety of oxytocin nasal spray in induction and enhancement of labour were tested in 102 patients. In 44 the pregnancies had been normal; in 58 the pregnancies were complicated by toxaemia, hypertension, post maturity, diabetes and elderly primigravidity. Foetal heart rate and amniotic fluid pressure were recorded continuously. 2. The efficacy of the spray was confirmed, but in contrast to previous reports significant uterine hyperactivity and hypoxic foetal heart rate changes were observed. 3. In 7 of the 102 patients the spray induced marked uterine hypertonus. Serious foetal bradycardia resulted and was followed by sustained tachycardia as uterine hyperactivity waned. Hypoxic foetal heart rate changes were more common when pregnancies were complicated. They were seen less frequently when the spray was employed in the induction of labour than in the enchancement of labour. 4. Oxytocin nasal spray lacks precision. The preparation used in this study delivered a higher dose than that reported in similar studies from U.S.A. A metered aerosol pack is undergoing trial. 5. Meanwhile, in complicated pregnancies uterine stimulation is more safely achieved by controlled intravenous infusion.

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