Background Depot medroxyprogesterone acetate (DMPA) is the most commonly used hormonal contraceptive method in South Africa. It is frequently administered in the immediate postnatal period, yet it is unclear whether it affects the risk of postnatal depression (PND).

Aim To determine whether DMPA increases the risk of PND compared with the copper-containing intrauterine device (IUD) when administered after delivery.

Design and setting A single-blind randomised controlled trial conducted at two teaching hospitals in East London, South Africa.

Methods Eligible, consenting women (N=242) requiring postnatal contraception were randomised to receive DMPA or an IUD within 48 hours of childbirth and interviewed at 1 and 3 months postpartum. Depression was measured using the Beck Depression Inventory (BDI-II) and the Edinburgh Postnatal Depression Scale (EPDS). Resumption of sexual intercourse, menstrual symptoms and breastfeeding rates were also assessed.

Results One-month EPDS depression scores were statistically significantly higher in the DMPA arm compared with IUD arm (p=0.04). Three-month BDI-II scores were significantly higher in the DMPA arm than in the IUD arm (p=0.002) and, according to the BDI-II but not the EPDS, more women in the DMPA arm had major depression at this time-point (8 vs 2; p=0.05). There were no statistically significant differences in other outcome measures except that fewer women had resumed sexual activity by 1 month postpartum in the DMPA arm (13% vs 26%; p=0.02).

Conclusions The possibility that immediate postnatal DMPA use is associated with depression cannot be excluded. These findings justify further research with longer follow-up.

Clinical trial number PACTR201209000419241.