Sex (Re)Ed: Depo-Provera Shot Could Keep Working Longer Than You Expect

If I wanted to get pregnant in the next year and a half, I might not want to start on the once-every-three-month Depo-Provera shot, a nurse at Planned Parenthood told me. The hormonal birth control shot Depo-Provera can be so long-lasting that it takes a woman more than a year to get pregnant after her last shot.

I had gone to Planned Parenthood to find a new form of birth control. I’d been on-again off-again with hormonal birth control pills for a while, and right then, I was off. I told the nurse there that while I thought the (non-hormonal) copper IUD sounded great, I wanted to have kids in a year or two, so I didn’t think the upfront expense or process of getting the IUD, a long-term birth control (the copper IUD can last for 10 years) made sense for me: I wanted Depo-Provera.

As far as hormonal birth control goes, the Depo-Provera shot has a lot to recommend it. Depo contains no estrogen, just progestin (unlike the patch, ring and most pills). In most women using Depo, periods become fewer and lighter, and after one year half of women using it stop having periods altogether. It’s only $35-$75 per injection (once every three months) at Planned Parenthood. It’s easier to manage a tri-monthly shot than a daily pill. And it’s very effective:

• Less than 1 out of 100 women will get pregnant each year if they always use the birth control shot as directed.
• About 6 out of 100 women will get pregnant each year if they don’t always use the birth control shot as directed.

Depo still has all the problems associated with hormonal birth control in general, though: Some women experience spotting between periods; some women report changes in their sex drive, weight gain, depression, headaches, nausea. And for women who may want to have kids in the near future, it comes with the added downside that it could tie up your ovaries for a lot longer than expected. According to Planned Parenthood:

On average, it takes up to six months longer for women to get pregnant after they stop using Depo-Provera than it does for women stopping other methods.

… the average time between the last Depo injection and pregnancy is about nine months, including the three months during which the injection is effective. This is why Depo is not usually prescribed for women who are planning to have a child in the very near future.

Even though I didn’t necessarily want to get pregnant within a year from that visit, I didn’t want to start on a form of birth control I’d have to then stop nine-months to a year-and-a-half before trying to get pregnant, either. [I went with the Nuva Ring; more on that later this week ...]

For those of you thinking, this sounds great!: Depo-Provera falls short of being a reliable long-term birth control method. Just because it can keep you from getting pregnant for over a year, it’s only generally guaranteed to do so for three months at a time. Pregnancy could happen anytime after 12 weeks from your shot.

Here’s how other birth control methods affect post-use fertility: 

IUD: Some researchers say there’s no delay in fertility after it’s removed; some say it can take 3-4 months after.

Oral contraceptives: Potential for 1 to 2 months of delayed fertility after use—but you could also get pregnant less than a month after stopping the pill.

Implanon: Return to fertility can occur after about 3 months.

Nuva Ring: Return to ovulation can occur in under a month.