Abstract
OBJECTIVES: To update a 2016 review and answer three questions: (1) Among women using an intrauterine device (IUD), does breastfeeding increase the risk of adverse events? (2) Among breastfeeding women, does IUD use increase the risk of adverse events? (3) Among breastfeeding women, does copper (Cu)-IUD use increase risk of adverse breastfeeding or infant outcomes? METHODS: We searched multiple databases from inception to August 2023. We extracted prespecified data and assessed risk of bias (RoB) for each article and certainty of evidence for each outcome. RESULTS: Thirty-eight articles met the inclusion criteria; 16 were newly identified since the previous review, most with high RoB. Evidence suggested no effect of breastfeeding on IUD-related adverse events (ie, expulsion, bleeding, pain and infection) compared with not breastfeeding; however, an increased relative risk of perforation was observed with breastfeeding at the time of IUD insertion compared with not breastfeeding. For perforation, relative measures of association ranged from 1.4 to 10.1, and absolute rates varied (eg, 0.6-7% or 6.8 per 1000). Evidence suggested no effect of IUD use on risk of adverse events (ie, bleeding, pain and infection) among breastfeeding women compared with no IUD use. Evidence suggested no effect of Cu-IUD use on breastfeeding or infant outcomes among breastfeeding women compared with no Cu-IUD use. CONCLUSIONS: We continued to find an increased relative risk of IUD perforation among breastfeeding women compared with no breastfeeding; however, the absolute risk is low. No other adverse effects with IUD use and breastfeeding were observed. The certainty of evidence for all outcomes was very low.