Identification of feto-maternal haemorrhage around labour using flow cytometry immunophenotyping

Area of Science:

• Obstetrics and Gynecology
• Perinatal Medicine
• Maternal-Fetal Medicine

Background:

• Feto-maternal haemorrhage (FMH) is the passage of fetal erythrocytes into maternal circulation.
• Quantifying FMH is crucial for understanding potential fetal risks and guiding management.
• The influence of delivery mode on FMH volume requires further investigation.

Purpose of the Study:

• To establish the normal range of feto-maternal haemorrhage (FMH) occurring during labor.
• To determine if the mode of delivery (vaginal, instrumental, cesarean) influences the volume of FMH.

Main Methods:

• Prospective cohort study of 346 women in their third trimester.
• Fetal erythrocytes in maternal blood quantified using flow cytometry immunophenotyping.
• FMH volume calculated by comparing pre- and post-delivery blood samples.

Main Results:

• Normal FMH due to labor ranged from <0.01 to 25.19 ml, with 96.13% of cases <1.15 ml.
• No overall statistical significance in FMH volume was found across different delivery types.
• Cesarean sections were associated with significantly higher FMH volumes compared to vaginal (p=0.001) and instrumental (p=0.008) deliveries.

Conclusions:

• Labor-associated feto-maternal haemorrhage (FMH) is generally small.
• While not a primary risk factor, cesarean delivery is linked to an increased likelihood of greater transplacental bleeding.
• Further research may be warranted to explore mechanisms behind increased FMH in cesarean births.