Obstetrical Outcomes of Increased Nucleated RBC in Maternal Blood during Early Pregnancy

Song, Geun A; Lee, Sang Hoon; Baek, Dong Hoon; Je, Goo Hwa; Han, Jin Yeong

Abstract

OBJECTIVE
During early pregnancy, CD71 and glycophorin A positive cells in peripheral blood of pregnant women were studied, to assess the relationship between increased numbers of nucleated RBC (NRBC) in maternal blood and pregnant outcomes.
METHODS
Peripheral venous blood samples were obtained from 47 primigravidas of 14~16 weeks gestation. Triple screening tests were routinely performed. Blood samples were incubated with monoclonal anti-CD71 and monoclonal anti-glycophorin antibodies, and analyzed by flow cytometry using FACSort (Becton Dickinson, USA) for checking the NRBC count.
RESULTS
A total of 47 pregnant women were enrolled at 14-16 weeks gestation; one pregnancy had anemia and was excluded from the test, the outcome was unknown for 2 other pregnancies, and twelve pregnancies had 1-4% of NRBC in the maternal blood. In the remaining 32 pregnant women, grouped according to their percentage of NRBC, the group with more than 4% of NRBC was termed the study group, and less than 1% of NRBC was termed the control group.The results were as follows: 1) The study group showed lower fetal birth weight than the control group, which was statistically negatively significant (y=-62.219x + 3,401.6, R2=0.2146, p<0.05).2) There was no significant correlation between the percentage of NRBC of maternal blood and maternal serum AFP level in the study and the control groups (y=-0.0206x + 1.2763, R2 =0.0096, p>0.05).3) There were two complications in the study group: one was a preterm delivery at 35 weeks of gestational age with birth weight of 2,300 gm and the other was a case of pregnancy-induced hypertension.
CONCLUSION
It can be concluded that increased NRBC count in maternal blood during the early second trimester has a significant correlation with fetal birth weight but can't predict high risk pregnancies such as preeclampsia, preterm labor or intrauterine fetal growth restriction.In order to obtain a higher predictive value, further studies with more participants and with high risk pregnancies of known risk factors are needed.