Table 5 Summary of oxytocin levels during pregnancy and in non-pregnant women

In the studies by Kumaresan 1974 [14], Vasicka 1978 [17], Dawood 1979 [18], Otsuki 1983 [20], De Geest 1985 [27], and Kuwabara 1987 [28], a rise of oxytocin levels was recorded with advancing pregnancy. These data demonstrate that oxytocin levels increase during pregnancy. Regardless of the basal levels, and the type of technique used for analysis of oxytocin levels, oxytocin levels increased about 2 to 4-fold. Oxytocin levels in non-pregnant women varied between 1.7 and 11.7 pg/mL.