Fig. 2From: Maternal plasma levels of oxytocin during physiological childbirth – a systematic review with implications for uterine contractions and central actions of oxytocinSchematic figure of oxytocin levels (relative values), and oxytocin pulse frequency, averaged over 30 min, in pregnancy and physiological labour and birth. Data compiled from Fuchs 1991 [31] in relation to: term pregnancy (1); first stage labour (2); second stage labour (3). Data in relation to birth (4) compiled from studies cited in Box 1: Rise of oxytocin levels in connection with birthBack to article page