Immediate start of hormonal birth control

Health care providers often tell women to wait until their next menstrual cycle to begin birth control pills. The main reason is to avoid using birth control during an undetected pregnancy. Another method involves starting the pills right away ('immediate start' or 'quick start'). Another birth control method should be used as back-up for the first seven days. Unclear issues were whether quick start of hormonal birth control works as well as the usual start and whether women like it. The quick start method might improve women's use of hormonal birth control.

In August 2012, did computer searches for randomized controlled trials of the quick-start method for pills and other hormonal birth control. We contacted researchers to find other studies. We included trials that compared quick start to the usual start of birth control. Also included were studies that compared quick start of different types of hormonal birth control with each other. Birth control methods could have the hormones estrogen and progestin (combined hormonal birth control) or just the progestin.

Five studies were included. In a study of 'depo,' which is given as a shot, fewer women with quick start of depo became pregnant than those who used another method for 21 days before depo. In this review, the numbers of women who stopped using their birth control method early were similar between groups in all trials. In the depo trial, more women with quick start of depo were very satisfied.

A trial of two quick-start methods showed women with the vaginal ring had less long-term bleeding and less frequent bleeding than those with pills. For six side effects, including changes in breasts, mood, and nausea, quick start of the ring showed fewer problems than quick start of pills. For satisfaction in that trial, more women in the ring group were very satisfied with their method of birth control.

We found little evidence that quick start leads to fewer pregnancies or fewer women stopping early. However, fewer women on quick start of depo became pregnant than the women who started with another method. Other differences were between types of birth control rather than start times. Women using the vaginal ring had fewer problems than women using birth control pills. More studies are needed comparing quick start versus usual start of the same hormonal birth control method.

Authors' conclusions: 

We found limited evidence that immediate start of hormonal contraception reduces unintended pregnancies or increases method continuation. However, the pregnancy rate was lower with immediate start of DMPA versus another method. Some differences were associated with contraceptive type rather than initiation method, i.e., immediate ring versus immediate COC. More studies are needed of immediate versus conventional start of the same hormonal contraceptive.

Read the full abstract...

Health care providers often tell women to wait until the next menses to begin hormonal contraception. The intent is to avoid contraceptive use during an undetected pregnancy. An alternative is to start hormonal contraception immediately with back-up birth control for the first seven days. Immediate initiation was introduced with combined oral contraceptives (COCs), and has expanded to other hormonal contraceptives. At the time of the initial review, how immediate start compared to conventional menses-dependent start was unclear regarding effectiveness, continuation, and acceptability. The immediate-start approach may improve women's access to, and continuation of, hormonal contraception.


This review examined randomized controlled trials (RCTs) of immediate-start hormonal contraception for differences in effectiveness, continuation, and acceptability.

Search strategy: 

In August 2012, we searched MEDLINE, CENTRAL, POPLINE, LILACS,, and ICTRP for trials of immediate-start hormonal contraceptives. We contacted researchers to find other studies. Earlier searches also included EMBASE.

Selection criteria: 

We included RCTs that compared immediate start to conventional start of hormonal contraception. Also included were trials that compared immediate start of different hormonal contraceptive methods with each other.

Data collection and analysis: 

Data were abstracted by two authors and entered into RevMan. The Peto odds ratio (OR) with 95% confidence interval (CI) was calculated.

Main results: 

Five studies were included. No new eligible studies have been found since the review was initially conducted. Method discontinuation was similar between groups in all trials. Bleeding patterns and side effects were similar in trials that compared immediate with conventional start. In a study of depot medroxyprogesterone acetate (DMPA), immediate start of DMPA showed fewer pregnancies than a 'bridge' method before DMPA (OR 0.36; 95% CI 0.16 to 0.84). Further, more women in the immediate-DMPA group were very satisfied versus those with a 'bridge' method (OR 1.99; 95% CI 1.05 to 3.77). A trial of two immediate-start methods showed the vaginal ring group had less prolonged bleeding (OR 0.42; 95% CI 0.20 to 0.89) and less frequent bleeding (OR 0.23; 95% CI 0.05 to 1.03) than COC users. The ring group also reported fewer side effects. Also, more immediate ring users were very satisfied than immediate COC users (OR 2.88; 95% CI 1.59 to 5.22).