All-Cause Severe Maternal Morbidity (SMM) and Transfusion-Only SMM Are Independently Associated with a Lower Likelihood of Exclusive Breastfeeding.

The rates of severe maternal morbidity (SMM) including blood transfusions after delivery are rising, yet little is known about the impact of these experiences on breastfeeding. This is a single-institution retrospective cohort study examining breastfeeding rates at three time points for 1,857 first-time parents delivered at term between July 1, 2016 and June 30, 2019. Our exposure of interest was SMM, which was subdivided into SMM where transfusion was the only indicator (transfusion-only SMM) and SMM where another indicator (diagnostic or procedural) was met, which may also include transfusion (all-cause SMM). Association between transfusion-only SMM and all-cause SMM with feeding method was determined using multinomial regression modeling and adjusting for relevant sociodemographic characteristics. The majority of those with uncomplicated deliveries were exclusively breastfeeding at the 2- to 4-week and 2- to 3-month time points (59.6% and 53.6%, respectively), in contrast to 46.3% and 42.0% of those who had experienced transfusion-only SMM, and 40.9% and 30% of those who had experienced all-cause SMM. In adjusted models, receipt of a blood transfusion was found to be associated with greater risk of exclusive formula feeding at all time points. Experience of all-cause SMM was significantly associated with increased likelihood of exclusive formula feeding at hospital discharge and the 2- to 3-month time point. We identified that experience of all-cause SMM and transfusion-only SMM are independently associated with a lower likelihood of exclusive breastfeeding after adjusting for sociodemographic factors. Perinatal clinicians should be aware of these risks and offer increased support to these couplets.