Abstract: Three studies that included 410 participants met the inclusion criteria of the review. We did not identify any ongoing trials. Two included studies were at low risk of selection, attrition, and reporting biases, but were at high risk of performance and detection biases due to the inability to blind participants to the intervention. One included study was at high risk of attrition bias. The overall quality of the evidence for each comparison ranged from very low to moderate; the main limitations were risk of bias and imprecision. Initiation rate of contraceptive implants at the first postpartum check-up visit was significantly higher in the immediate insertion group than in the delayed insertion group (RR 1.41, 95% CI 1.28 to 1.55; three studies, 410 participants; moderate quality evidence). There appeared to be little or no difference between the groups in the continuation rate of contraceptive implant used at six months after insertion (RR 1.02, 95% CI 0.93 to 1.11; two studies, 125 participants; low quality evidence) or at 12 months after insertion (RR 1.04; 95% CI 0.81 to 1.34; one study, 64 participants;very low quality evidence) Women who received an immediate postpartum contraceptive implant insertion had a higher mean number of days of abnormal vaginal bleeding within six weeks postpartum (MD 5.80 days, 95% CI 3.79 to 7.81; one study, 215 participants; low quality evidence) and a higher rate of other side effects in the first six weeks after birth (RR 2.06, 95% CI 1.38 to 3.06; one study, 215 participants; low quality evidence) than those who received a delayed postpartum insertion. There appeared to be little or no difference between the groups in heavy, irregular vaginal bleeding or associated severe cramping within 12 months (RR 1.01, 95% CI 0.72 to 1.44, one study, 64 participants;very low quality evidence). It was unclear whether there was any difference between the groups in scores for participant satisfaction on a 0-10 scale (MD -0.40, 95% CI -1.26 to 0.46, low quality evidence), or in rates of unintended pregnancy (RR 1.82, 95% CI 0.38 to 8.71, 1 RCT, 64 women, very low quality evidence) at 12 months, or in rate of breastfeeding rate at six months (RR 2.01, 95% CI 0.72 ro 5.63, 1 RCT, 64 women, very low quality evidence) rate did not differ significantly between the groups. Evidence from this review indicates that the rate of initiation of contraceptive implant at the first postpartum check-up visit was higher with immediate postpartum insertion than with delayed insertion. There appeared to be little or no difference between the groups in the continuation rate of contraceptive implant use at 6 months. It was unclear whether there was any difference between the groups in continuation of contraceptive use at 12 months or in the unintended pregnancy rate at 12 months.

Plain-language summary: We searched for randomised studies up to 28 October 2016. We looked at whether insertion of contraceptive implant soon after childbirth or when women come back for the first postpartum check-up affected use of this contraception method. We included three studies with a total of 410 women. Use of a contraceptive implant was higher when it was applied right after childbirth than when it was applied four to six weeks later. There appeared to be little or no difference between the groups in the continuation rate of contraceptive implant use at 6 months. It was unclear whether there was any difference between the groups in continuation of contraceptive use at 12 months or in the unintended pregnancy rate at 12 months. Although vaginal bleeding and other adverse effects in the first six weeks after birth including nausea, hair loss, hirsutism, headache, and acne seem to be higher in women that receive this method a few days after childbirth rather than four to six weeks later, this finding however cannot be definitely concluded as all participants knew the nature of the intervention they received (were not blinded) and the reports of these adverse effects were not objectively assessed. It was unclear whether there was any difference between the groups at 12 months in heavy, irregular vaginal bleeding or associated severe cramping, rates of unintended pregnancy, or in measures of participants' satisfaction. Nor was it clear whether there was any difference in breastfeeding rates at 6 months. The included studies were conducted in the USA, and generalisation of these findings to other population or settings should be applied with caution. Overall, the quality of the evidence was moderate to very low. The main limitations were imprecision and risk of bias (related to lack of blinding and to attrition). Further good quality, well-designed randomised controlled trials will provide additional information.