Effect of oral contraceptives on the production and composition of human milk

Abstract

Summary One hundred and thirty six lactating women were studied, 42 controls and 94 taking oral contraceptives. Combination pills of oestrogen and progestogen (Primovlar and Minovlar) and a low dose progestogen pill (Norgestrel) were used. The selection of a particular formulation was based on the endocrine profile of an individual; this reduced drop-outs due to side effects. The change in the quantity of milk was assessed by test-feeding followed by manual expression. Milk was also analysed quantitatively. Significant reduction in the milk yield was found with the Primovlar and Minovlar groups but no change was observed with Norgestrel. No change in the quality of milk was found for any of the three groups.