Hemoglobin on Admission for Childbirth and Postpartum Acute Care Use in a Southeastern Health Care System

Objective Our objective was to evaluate whether hemoglobin on admission for childbirth is associated with postpartum acute care use (ACU). Study Design We conducted a retrospective cohort study of patients giving birth at a southeastern quaternary care hospital from January 2018 through June 2021 using electronic health records. Predelivery hemoglobin was categorized as <9, 9- < 10, 10- < 11, 11- < 12, and >= 12 g/dL. Acute care was defined as a visit to obstetric triage, the emergency department, or inpatient admission within 90 days postpartum. Generalized estimating equations quantified the crude and multivariable-adjusted association between predelivery hemoglobin and ACU. Results Among 8,677 pregnancies, 1,467 (17%) used acute care in the system within 90 days postpartum. In unadjusted models, those with predelivery hemoglobin <9 had twice the risk of postpartum ACU compared to those with hemoglobin >= 12 (95% confidence interval [CI]: 1.59-2.69), with a decrease in risk for each increase in hemoglobin category (9- < 10 g/dL: risk ratio [RR]: 1.47, CI: 1.21-1.79; 10- < 11 g/dL: RR: 1.44, CI: 1.26-1.64; 11- < 12 g/dL: RR: 1.20, CI: 1.07-1.34). The adjusted model showed a similar trend with smaller effect estimates (<9 g/dL: RR: 1.50, CI: 1.14-1.98; 9- < 10 g/dL: RR: 1.22, CI: 1.00-1.48; 10- < 11 g/dL: RR: 1.22, CI: 1.07-1.40; 11- < 12 g/dL: RR: 1.09, CI: 0.98-1.22). Conclusion Low hemoglobin at childbirth admission was associated with increased postpartum ACU. Low hemoglobin on admission could signal to providers that additional follow-up, resources, and ongoing support are warranted to identify and address underlying health needs. Because hemoglobin is routinely assessed during the childbirth hospitalization, this indicator may be especially valuable for risk assessment among patients with limited prior engagement in health care.