Effect of contraceptive steroids on human lactation.

Biochemical studies to detect changes occurring in the composition of mother's milk from the initiation of proper lactation to weaning were done in a group of 36 postpartum women, volunteers who were either using the conventional contraceptives or taking a low-dose combination pill, a low-dose progestational compound, or a 3 or 6 monthly injection as a mode of contraception. Apart from a significant increase in the protein content of milk and a slight increase in the quantity, the 3 monthly injection group behaved exactly like the control. On the other hand, the 6 monthly injection group showed a significant increase in quantity but with a significant decrease in protein, fats, and calcium. The low-dosage progestogens group showed a significant decrease in the quantity of fats and the calcium content of milk, but, surprisingly, the addition of 10 micrograms of estrogens to the low-dosage progestogen indicated a pattern almost similar to the control.