A Tennessee regional health officer reviews the literature to see whether use of combined oral contraceptives (OCs) during lactation affects infant growth and development. He looks at studies with anthropometric measurements, those measuring the amount of steroid secreted in breast milk, and case reports on direct effects of the hormones on the nursing infant. All the studies have weaknesses. Inconsistencies exist between the studies. Study design and conditions can explain some of the inconsistencies. One pattern arises in these studies: use of an OC with more than 50 mcg of estrogen early in the postpartum period negatively affects breast feeding (e.g., reduced infant growth). Other than this, there are no consistent findings of adverse effects of combined OC use on infant growth and development after lactation is established. Some studies show that postpartum women who want to use contraception often have few contraception choices other than OCs, so they choose OCs rather than continue breast feeding. This denies the infant its best source of nutrition. Yet, lactating women who forego contraceptive use may place themselves at risk of an early pregnancy as well as place the child at risk due to short birth spacing. Women who want to use OCs and wait long enough to establish lactation (about 2 months) should not be at risk of pregnancy, however. Another reason for not using OCs immediately postpartum is that women in that period are at an increased risk of thrombotic complications. Based on this literature review, the health official concludes that combined OC use during lactation is reasonable and scientifically justifiable. He does recommend, however, that lactating women use the lowest possible dose OC no sooner than 2-3 months postpartum. They should take the pill each day at the beginning of the longest interval between feedings. They should also allow more suckling time to counteract any possible reduction in the breast milk supply.