Fetal loss, twinning and birth weight after oral-contraceptive use

To evaluate the effect of oral-contraceptive use on subsequent offspring, I reviewed information on the pregnancies of 19,887 women who indicated, in response to a mail questionnaire, that they had used oral contraceptives. The rates of spontaneous abortion and stillbirth were smaller for former users than for nonusers--a finding consistent with previous studies. Twinning was more frequent among births of infants conceived soon after cessation of oral contraceptives, the rate being approximately twice the expected value for women who had used oral contraceptives for more than six months (P = 0.1). The sex distribution of the twins indicated that the increase was mainly in dizygous twins (P = 0.02), in accordance with predictions about increased twinning after cessation of oral contraceptive use. No relation was evident between oral contraceptive use and birth weight.

Related Concept Videos

Teratogenicity01:07

Teratogenicity

The ability of a drug to produce structural deformations and functional abnormalities in the developing embryo or the fetus is called teratogenicity, and the drug producing this effect is known as a teratogen. Teratogenic effects include stillbirth, miscarriage, intrauterine growth restriction, and neurocognitive delay. A teratogen may affect the embryo at different stages of development, which is important in determining the type and extent of the damage. During blastocyst formation, the early...
Ovarian Cycle01:27

Ovarian Cycle

The menstrual cycle includes a critical component known as the ovarian cycle, which undergoes two main phases each month—the follicular phase and the luteal phase. The follicular phase is variable and averaging around 14 days. Ovulation, triggered by a surge in luteinizing hormone (LH), marks the transition between the two phases. The second phase, the luteal phase, is relatively consistent, lasting approximately 14 days, and is marked by the activity of the corpus luteum. While a cycle length...
Birth Control Methods01:22

Birth Control Methods

Vasectomy is a surgical form of male sterilization that involves severing and sealing the vasa deferentia, preventing sperm from mixing with semen during ejaculation. Because a vasectomy does not impact the testes' ability to produce testosterone, hormone levels, libido, and sexual function generally remain unchanged. While vasectomy is highly effective in preventing pregnancy, with a success rate near 99.85%, rare cases of recanalization (spontaneous reconnection) can occur. Although vasectomy...