In every pregnancy, a woman starts out with a 3-5% chance of having a baby with a birth defect. This is called her background risk. This sheet talks about whether exposure depot medroxyprogesterone may increase the risk for birth defects over that background risk. This information should not take the place of medical care and advice from your health care provider.

What is depot medroxyprogesterone?

Depot medroxyprogesterone is a man-made hormone similar to the female hormone progesterone. Depot medroxyprogesterone is sold under the brand name Depo Provera®.

Depot medroxyprogesterone injection is effective for preventing pregnancy for approximately 90 days but may be found in the bloodstream longer. It is recommended that women receive a shot every 90 days to prevent pregnancy. Depot medroxyprogesterone is not the same as oral birth control pills which contain other hormones.

Depot medroxyprogesterone can also be used to treat menstrual disorders and, at high doses, can be used to treat certain types of cancer. This fact sheet is written specifically for the contraceptive depot medroxyprogesterone injection.

How does it work?

Depot medroxyprogesterone prevents pregnancy by stopping the release of the egg during a woman’s monthly cycle. If a woman does not release an egg during her monthly cycle, she cannot become pregnant.

I got pregnant within three months of my depot medroxyprogesterone shot; will my baby be more likely to have birth defects?

High doses of the hormone in depot medroxyprogesterone and other man-made progestogen hormones have been linked to babies born with external (outside) genitals that are not clearly male or female (called ambiguous genitalia) in animal and human studies. These effects do not change the internal (inside) reproductive organs or sexual behavior. These effects are thought to happen less than 1% of the time.

The majority of studies have not found an association between non-genital birth defects after depot medroxyprogesterone exposure during the first trimester. Also, children exposed to depot medroxyprogesterone during pregnancy or breastfeeding did not show adverse effects on their long-term health or development, including the age or stage when a person can reproduce (called sexual maturity).

Are there any other problems depot medroxyprogesterone can cause?

One study found that babies born to mothers who received their last depot medroxyprogesterone shot within four weeks of getting pregnant were a little more likely to have babies with lower birth weight than those born to mothers who had unplanned pregnancies for other reasons. Other studies of mothers on depot medroxyprogesterone have not supported this finding. More studies are needed to determine if there is an increased risk for lower birth weight if you become pregnant when using depot medroxyprogesterone for contraception.

What are the effects on my baby if I was already pregnant when I received my depot medroxyprogesterone shot?

One study showed there may be an increased risk of neonatal and infant death when exposed to depot medroxyprogesterone during pregnancy. These babies were also more likely to have a lower birth weight than babies not exposed. No other studies have shown an increase in birth defects or long term health issues from use of depot medroxyprogesterone during pregnancy. Also, there is no evidence that depot medroxyprogesterone causes an increased risk for ectopic pregnancy (when a fertilized egg implants somewhere other than the uterus), or pregnancy loss. When you know you are pregnant you should not continue getting the depot medroxyprogesterone injections.

Are there any effects if I use depot medroxyprogesterone while breastfeeding?

One study found that the amount of prolactin, the hormone needed for breast milk production, is slightly increased in women using depot medroxyprogesterone. Based on this, it is unlikely that depot medroxyprogesterone will lower the amount of breast milk produced. If a woman is going to use depot medroxyprogesterone, the World Health Organization has recommended waiting 6 weeks after the baby’s birth to make sure that an adequate milk supply has been established. In women using depot medroxyprogesterone during breastfeeding, the amount of hormone found in the breast milk is very small. Many studies have shown that the hormone in breast milk appears to have no effect on the baby’s long term growth and development. The use of depot medroxyprogesterone has been approved by the American Academy of Pediatrics for use in breastfeeding mothers. Be sure to talk to your health care provider about all your choices for breastfeeding.

Selected References:

  • Baheiraei A, et al. 2001. Effects of progestogen-only contraceptives on breast-feeding and infant growth Int J Gynaecol Obstet, 74; 203–205
  • Borgatta L, et al. 2002. Pregnancies diagnosed during Depo- Provera use.Contraception. Sep;66(3):169-72.
  • Dahlberg K. 1982. Some effects of depotmedroxyprogesterone acetate (DMPA): Observations in the nursing infant and in the long-term user. Int J Gynaecol Obstet 20:43-48.
  • Jaffe B, et al. 1990. Health, growth and sexual development of teenagers exposed in utero to medroxyprogesterone acetate. Paediatr Perinat Epidemiol 4:184-95.
  • Jimenez J, et al. 1984. Long-term follow-up of children breast-fed by mothers receiving depotmedroxyprogesterone acetate. Contraception 30:523-533.
  • Koetsawang S, et al. 1982. Transfer of contraceptive steroids in milk of women using long-acting gestagens. Contraception 25:321- 331.
  • Pardthaisong T, et al. 1992. The long-term growth and development of children exposed to Depo-Provera during pregnancy or lactation. Contraception 45:313-24.
  • Pardthaisong T and Gray RH. 1991. In utero exposure to steroid contraceptives and outcome of pregnancy. Am J Epidemiol 134:795-803.
  • Pardthaisong T and Gray RH. 1991. In utero exposure to steroid contraceptives and survival during pregnancy. Am J Epidemiol 134:804-811.
  • Ratchanon S and Taneepanichskul S. 2000. Depot medroxyprogesterone acetate and basal serum prolactin levels in lactating women. Obstetrics & Gynecology 96(6):926-8.
  • Saxena BN, et al. 1977. Levels of contraceptive steroids in breast milk and plasma of lactating women. Contraception 16:605-613.
  • Virutamasen P, et al. 1996. Pharmacodynamic effects of depot-lprogesterone acetate (DMPA) administered to lactating women on their male infants. Contraception 54:153-157.
  • Yovich JL, et al. 1988. Medroxyprogesterone acetate therapy in early pregnancy has no apparent fetal effects. Teratology 38:135-144.