Factor VIII in pregnancy and birthweight.

Area of Science:

• Obstetrics and Gynecology
• Hematology
• Reproductive Biology

Background:

• Factor VIII clotting activity (VIIIC) and factor VIII related antigen (VIIIR) are crucial in hemostasis.
• Their levels fluctuate during pregnancy, potentially influencing obstetric outcomes.
• Understanding these variations is key to managing pregnancy-related complications.

Purpose of the Study:

• To investigate the distribution of VIIIC and VIIIR during pregnancy.
• To determine the relationship between these factors and infant birthweight.
• To explore associations with maternal and infant characteristics.

Main Methods:

• Blood samples were collected from 495 pregnant women at 28 and 34 weeks gestation.
• Assays were performed for factor VIII clotting activity (VIIIC) and factor VIII related antigen (VIIIR).
• Statistical analyses examined relationships with birthweight, gestational age, infant sex, parity, maternal hypertension, ethnicity, and blood group.

Main Results:

• A weak positive correlation was found between VIIIR and birthweight, adjusted for covariates.
• Factor VIIIC levels at 34 weeks were lower in pregnancies with male infants.
• Elevated VIIIR/VIIIC ratios were observed in hypertensive pregnancies, without impacting birthweight.
• VIIIR and VIIIC levels at 28 weeks were lower in multiparous women and those with longer gestation.
• Asian women exhibited higher mean VIIIC than Caucasian women; blood group O was associated with lower VIIIR and VIIIC.

Conclusions:

• Factor VIII levels during pregnancy exhibit complex associations with various factors but have limited direct clinical correlation with birthweight.
• Infant sex, maternal parity, ethnicity, and hypertensive status influence factor VIII levels.
• Further research may elucidate the clinical significance of these variations in obstetric care.