The effect of the oral contraceptive Ovosiston on the composition of human milk.

At Ain Shams University Hospital Cairo a study of the effect of the oral contraceptive Ovosiston (3.0 mg chlormadinone acetate and .1 mg mestranol) compared milk composition of 20 lactating controls to 20 lactating mothers (20-35 years) taking Ovosiston for 4 months. Samples of milk were collected and analyzed monthly for total solids ash chlorides lactose fat and total proteins and their fractions. Total solids ash chloride and lactose were the same in both groups. Milk fat was increased 30% over normal values in women taking Ovosiston. Total proteins and immunoglobulins alpha-lactalbumin beta-lactoglobulin blood serum albumin gamma beta and alpha-caseins all showed a 10% decrease in treated women as compared to controls. Mothers on Ovosiston claimed adequate milk yield.