OBJECTIVE:

To evaluate the fetal, neonatal, and long-term prognosis of massive fetomaternal hemorrhage (20 mL or more).

METHODS:

This series includes all patients with Kleihauer test values of 40 per 10,000 or higher over an 8-year period at two university hospitals. We examined obstetric, neonatal, and subsequent outcome data for the children.

RESULTS:

During the study period, 48 patients had massive fetomaternal hemorrhage (crude incidence 1.1 per 1,000; corrected incidence for Rh-negative women 4.6 per 1,000). Six fetal deaths were observed, representing 1.6% of all fetal deaths during the period. Nine newborns (18.7%) were transferred to neonatal intensive care unit (NICU) and five (10.4%) had transfusions. Fetomaternal hemorrhages of 20 mL/kg or more significantly increased the risk of fetal death, induced preterm delivery, transfer to NICU, and neonatal anemia requiring transfusion. Long-term follow-up was not associated with neurological sequelae (0%, 95% confidence interval 0.0-11.6%).

CONCLUSION:

When the transfused volume equals or exceeds 20 mL/kg, massive fetomaternal hemorrhage may lead to severe prenatal or neonatal complications.

LEVEL OF EVIDENCE:

III.