Can you get pregnant on the Depo shot?

When it comes to birth control methods like the Pill, you know there are things you have to do on your end to ensure effectiveness. That's why many women chose alternate approaches like Depo-Provera -- administered via injection from your physician every 12 weeks, eliminating the daily contraception management.

The consequences of incorrect usage are out of your hands. Because of this, Depo-Provera is a highly effective method of birth control, with an approximate 99 percent success rate. Only about 3 in 1,000 women will become pregnant while on the contraceptive [source: American Pregnancy Association]. However, even the best birth control can fail on rare occasions. So, yes, there is a very slight possibility you can get pregnant on Depo-Provera.

What exactly is thishormonal contraceptive? Much like the Pill, it prevents ovulation and makes the cervix and uterine lining hostile to sperm and fertilized eggs. It uses a synthetic version of the hormone progesterone to achieve these results. Unlike the Pill, your physician will give you a shot, usually in the arm or buttocks.

If Depo-Provera shots are received on a recommended basis, pregnancy is highly unlikely. While the contraceptive has the power to prevent conception up to 14 weeks, the injections are usually given every 12 weeks to ensure that there is no gap in the effectiveness of the birth control between shots. When such a schedule is maintained, pregnancy while on Depo-Provera is extremely rare [source: DiLeo].

While there is a very slight risk of ectopic pregnancy (a pregnancy in which the fetus develops outside the uterus) if a woman conceives while on Depo-Provera, it's less likely to occur with this birth control method than it is with others [source: New Mexico Department of Health and Family Planning].

Damage to the fetus is also unlikely. A study of newborns who were exposed to Depo-Provera while in the womb found that there was no significant difference in birth weight or birth defects compared to other babies [source: Dahlberg]. Further research found that Depo-Provera doesn't impact the long-term development of children who were exposed to the contraceptive while in the womb [source: Pardthaisong].

Now that you know about Depo-Provera, keep reading for lots more information on birth control on the next page.