The relationship between oxytocin blood concentrations and antidepressants over pregnancy and the postpartum

Antidepressant treatment of perinatal depression is increasingly common and accepted in clinical guidelines. It has been suggested that serotonergic antidepressants may effect changes in the oxytocinergic system, including oxytocin levels, and that this may be one of the beneficial mechanisms of action for these drugs. Furthermore, oxytocin has been associated with the quality of the parent-child relationship, which may be important in treatment of perinatal depression. This study will explore if there is a relationship between antidepressant use over the perinatal period and oxytocin levels. Data from a pregnancy cohort study are used from 279 women across three groups: women taking antidepressants in pregnancy (n = 48), women with untreated depression (n = 31) and healthy control women (n = 200). Data included antidepressant use, maternal depression and oxytocin plasma concentrations in pregnancy and up to 12 months postpartum. We found that concurrent oxytocin blood concentrations were not associated with perinatal antidepressant use. However, oxytocin blood concentrations increased more steeply in those on antidepressants across the perinatal period compared to control women. A steeper increase for Selective Serotonergic Reuptake Inhibitors was observed, however, this effect was on the boarder of statistical significance. In conclusion, although antidepressant use and oxytocin was not associated at any time point, women taking antidepressants during pregnancy had larger increases in oxytocin over the perinatal period. Future research could examine specific agents and class of antidepressant and the relationship to parenting.