Background This systematic review summarises association between short interpregnancy intervals and adverse perinatal health outcomes in high‐resource settings to inform recommendations for healthy birth spacing for the United States. Methods Five databases and a previous systematic review were searched for relevant articles published between 1966 and 1 May 2017. We included studies meeting the following criteria: (a) reporting of perinatal health outcomes after a short interpregnancy interval since last livebirth; (b) conducted within a high‐resource setting; and (c) estimates were adjusted for maternal age and at least one socio‐economic factor. Results Nine good‐quality and 18 fair‐quality studies were identified. Interpregnancy intervals <6 months were associated with a clinically and statistically significant increased risk of adverse outcomes in studies of preterm birth (eg, aOR ≥ 1.20 in 10 of 14 studies); spontaneous preterm birth (eg, aOR ≥ 1.20 in one of two studies); small‐for‐gestational age (eg, aOR ≥ 1.20 in 5 of 11 studies); and infant mortality (eg, aOR ≥ 1.20 in four of four studies), while four studies of perinatal death showed no association. Interpregnancy intervals of 6‐11 and 12‐17 months generally had smaller point estimates and confidence intervals that included the null. Most studies were population‐based and few included adjustment for detailed measures of key confounders. Conclusions In high‐resource settings, there is some evidence showing interpregnancy intervals <6 months since last livebirth are associated with increased risks for preterm birth, small‐for‐gestational age and infant death; however, results were inconsistent. Additional research controlling for confounding would further inform recommendations for healthy birth spacing for the United States.

Background Currently, no federal guidelines provide recommendations on healthy birth spacing for women in the United States. This systematic review summarises associations between short interpregnancy intervals and adverse maternal outcomes to inform the development of birth spacing recommendations for the United States. Methods PubMed/Medline, POPLINE, EMBASE, CINAHL, the Cochrane Database of Systematic Reviews, and a previous systematic review were searched to identify relevant articles published from 1 January 2006 and 1 May 2017. Included studies reported maternal health outcomes following a short versus longer interpregnancy interval, were conducted in high‐resource settings, and adjusted estimates for at least maternal age. Two investigators independently assessed study quality and applicability using established methods. Results Seven cohort studies met inclusion criteria. There was limited but consistent evidence that short interpregnancy interval is associated with increased risk of precipitous labour and decreased risks of labour dystocia. There was some evidence that short interpregnancy interval is associated with increased risks of subsequent pre‐pregnancy obesity and gestational diabetes, and decreased risk of preeclampsia. Among women with a previous caesarean delivery, short interpregnancy interval was associated with increased risk of uterine rupture in one study. No studies reported outcomes related to maternal depression, interpregnancy weight gain, maternal anaemia, or maternal mortality. Conclusions In studies from high‐resource settings, short interpregnancy intervals are associated with both increased and decreased risks of adverse maternal outcomes. However, most outcomes were evaluated in single studies, and the strength of evidence supporting associations is low.

OBJECTIVE: Counseling about potential side effects and health benefits of contraceptive methods could facilitate continued method use and method satisfaction, yet no evidence-based compilation of side effects and benefits exists to aid such counseling. Among contraceptive methods in the United States, depot medroxyprogesterone acetate (DMPA) injectables have the highest discontinuation rates, and most discontinuation is attributable to side effects. This review examines the side effects and health benefits of DMPA to inform counseling. DATA SOURCES: We searched PubMed, POPLINE, EMBASE, Web of Science, Campbell Collaboration Library of Systematic Reviews, the Cochrane Database of Systematic Reviews, the Cochrane Center Register of Controlled Trials, and ClinicalTrials.gov. METHODS OF STUDY SELECTION: We included English-language studies published from 1985 to 2016 that enrolled healthy, nonbreastfeeding females aged 13–49 years at risk of unintended pregnancy, compared intramuscular or subcutaneous progestin-only injectables to a contemporaneous comparison group, and addressed at least one key question: 1) What side effects are associated with progestin-only injectable contraceptive use? 2) What health benefits are associated with progestin-only injectable contraceptive use? Study quality was assessed using criteria from the U.S. Preventive Services Task Force. TABULATION, INTEGRATION, AND RESULTS: Twenty-four studies met inclusion criteria. None were randomized controlled trials. There were 13 prospective cohort, five retrospective cohort, four case–control, and two cross-sectional studies. Studies of moderate or high risk of bias suggest an association between DMPA use and weight gain, increased body fat mass, irregular bleeding, and amenorrhea. Inconsistent evidence exists for an association between DMPA use and mood or libido changes. Limited evidence exists for an association between DMPA use and decreased risk of cancers and tubal infertility. CONCLUSION: Higher-quality research is needed to clarify DMPA's side effects and benefits. In absence of such evidence, patient-centered counseling should incorporate the available evidence while acknowledging its limitations and recognizing the value of women's lived experiences.