Fertility May Be Delayed After Stopping Certain Types of Birth Control

Some birth control might cause temporary delays in the return offertilityafter a person stops taking it, according to a new study.

Cisgender women using oral contraceptives, the contraceptive ring, and some long-acting reversible contraceptive methods experienced short-term delays in areturn to fertilitycompared to users of barrier methods, according to research published in peer-reviewed medical trade journalThe BMJ.

"Women who used injectable contraceptives had the longest delay in return of normal fertility (five to eight cycles), followed by users of patch contraceptives (four cycles), users of oral contraceptives and vaginal rings (three cycles), and users of hormonal and copper intrauterine devices and implant contraceptives (two cycles)," says Jennifer Yland, lead author of the study and a doctoral student in epidemiology at Boston University.

The Study's Findings

The study evaluated how long it took cisgender women tobecome pregnant"in relation to recency and length of use of various hormonal and non-hormonal contraceptive methods." (Transgender and non-binary people also use contraception, but they were not included in this study.)

Through online surveys, almost 18,000 cisgender women from three cohort studies of people planning pregnancies reported their use of contraception, lifestyle factors, and their medical histories. Researchers sent out follow-up questionnaires every two months for 12 months or until a pregnancy was reported, the study says.

e study found that "use of some hormonal contraceptive methods was associated with delays in return of fertility, with injectable contraceptives showing the longest delay." But the findings indicated "little or no lasting effect of long term use of these methods on fecundability," which is the probability of becoming pregnant within one menstrual cycle.

"For all hormonal contraceptive methods, delays in the return to normal fertility were temporary," Yland says. "Overall, we found this to be quite reassuring. For certain hormonal methods, such as injectables, delays in the return of fertility were considerably longer than that shown for oral contraceptives. These findings should be taken into account when people are considering contraceptive choice in the context of family planning and infertility management."

What This Adds to Existing Evidence

Yland says she was interested in the topic because "many people are concerned about the potential effects of contraception on future fertility." She added, "Use of long-acting reversible contraceptive (LARC) methods (IUDs, implants, patches, and injectable contraceptives) has become increasingly common worldwide, but previous research on this topic has focused mostly on oral contraceptives.

Previous research on oral contraceptives has similarly found that any delays in the return of fertility after a person stops taking oral contraceptives are temporary.

It takes time for fertility to return after stopping use of a contraceptive because a person's cycle and ovulation have to return to normal, which could take up to three months after stopping use of the birth control pill. As Yland's study found, that length of time could be longer—five to eight menstrual cycles, or about four to eight months—for users of injectable contraceptives likeDepo-Provera．

A 2011 literature review of available evidence found the typical one-year pregnancy rates for the various contraceptives

• After stopping oral contraceptives, one-year pregnancy rates ranged between 79% and 96%
• For copper IUDs, between 71% and 91%
• For contraceptive implants, between 77% and 86%
• For injectable contraceptives, only two studies were reported at the time, which found that one-year pregnancy rates after stopping use of the contraceptive were 73% and 83%, respectively.

"There was no evidence of increased pregnancy complications or adverse fetal outcomes following cessation of any of the reversible methods reported," the 2011 review found.

Mary Jane Minkin, MD, clinical professor of obstetrics and gynecology at Yale University, says the newBMJstudy "confirmed what we've known for a while": that the contraceptive injection can delay fertility once someone stops using it.

"It can hang around and 'mess' with ovulation for a number of months beyond its official 'time up,'" she says. "So I have always counseled women about contraceptive choices: if you are coming to me and saying 'I am getting married next week, and I want to get pregnant three months from now,' I would never suggest a Depo-Provera injection—because it's very variable as far as when it will truly wear off."

Minkin says that she always asks patients what their family planning time frame looks like before recommending a contraceptive. If they want to become pregnant in a year, for example, they might not want to go through having an IUD inserted for only a year's worth of use. Rather, there are low-dose hormonal contraceptives like the reusable ring.

"The bottom line is you really need to take into account women's desires for contraception, when ideally they'd like to conceive, and how easy do they want their method to be—and come up with a very workable solution or two for them,” Minkin says.