Effect of nipple stimulation on uterine activity and on plasma levels of oxytocin in full term, healthy, pregnant women

The effect of nipple stimulation on uterine activity, foetal heart rate and plasma oxytocin level in healthy full term pregnant women was studied. Ten women in weeks 38-39 of pregnancy stimulated their nipples for 30 min. Nine of the ten experienced uterine contractions. One woman showed signs uterine hyperactivity (frequent contractions) and foetal heart rate decelerations. Blood samples were drawn at 15 s intervals during 5-6 contractions and oxytocin levels were measured with radioimmunoassay. Oxytocin levels rose significantly during the nipple stimulation and short bursts of oxytocin were recorded during contractions. Nipple stimulation has been used to induce labour and our data may suggest that oxytocin released in response to such stimulation is responsible for the contractions induced.