Massive fetomaternal hemorrhage: Manitoba experience

Area of Science:

• Obstetrics and Gynecology
• Perinatal Medicine
• Hematology

Background:

• Fetomaternal hemorrhage (FMH) is the transfer of fetal blood to the maternal circulation.
• Massive FMH, defined as significant fetal blood loss, can lead to adverse perinatal outcomes.
• Understanding the incidence and outcomes of massive FMH is critical for clinical management.

Purpose of the Study:

• To determine the incidence, size, and perinatal outcomes of spontaneous massive fetomaternal transplacental hemorrhage (FMH).
• To assess the frequency of significant fetal blood loss in Rh-negative women and in cases of unexplained fetal distress or neonatal anemia.

Main Methods:

• Review of Kleihauer maternal-fetal screening records from October 1970 to December 1992.
• Analysis of Rh Laboratory correspondence for cases with known fetal and neonatal outcomes.
• Inclusion criteria: fetomaternal transplacental hemorrhage of at least 80 mL or 150 mL of fetal blood.

Main Results:

• The incidence of FMH of at least 80 mL was 1 in 1146 pregnancies; 150 mL or more occurred in 1 in 2813 pregnancies.
• In selected cases due to fetal distress or neonatal anemia, the incidence of FMH of at least 150 mL was 1 in 4360 pregnancies.
• Adverse perinatal outcomes occurred in 46% of cases with massive FMH (150 mL or more), including ten perinatal deaths and one case of spastic quadriplegia.

Conclusions:

• Massive fetomaternal transplacental hemorrhage, while uncommon, is associated with a high incidence of adverse perinatal outcomes.
• A high index of suspicion, prompt investigation, and appropriate management are essential to improve outcomes.
• Early detection and intervention strategies are vital for managing massive FMH and mitigating risks.