Clinical utility of routine postpartum hemoglobin determinations.

The objective of this paper was to determine if routine postpartum hemoglobin (Hb) determination changes patient management. One thousand patients with a vaginal delivery at Hermann Hospital, Houston, TX, had antepartum Hb testing, and a postpartum Hb for: (1) an antepartum Hb <9.0 mg/dL, (2) an estimated blood loss (EBL) >500 mL, (3) abnormal orthostatic vital signs, and (4) physician discretion. Data collected included: antepartum and postpartum Hb, EBL at delivery, the indication for Hb determination, and orthostatic vital sign results. Three-hundred fifty-eight postpartum hemoglobins were performed, most were "routine." Patients whose EBL was >500 mL were twice as likely to be anemic after delivery (RR 2.39, 95% CI 1.40, 4.08). Orthostatic hypotension had a PPV of only 21% for postpartum anemia. With the exception of an EBL >500 mL, risk factors for postpartum anemia are poorly predictive. Orthostatic vital signs are an insensitive test for the detection of anemia. Minimizing routine Hb testing following vaginal deliveries appears safe without an impact on patient management.