Correlation of hematocrit and Apgar scores in newborns of women with hypertensive disorders in pregnancy

To compare the incidence of polycythemia in newborns of women with hypertensive disorders in pregnancy (HDP) with those of normotensive mothers, to determine the incidence of perinatal stress using Apgar scores and to correlate hematocrit with Apgar scores in these newborn.

This was a hospital-based comparative study conducted in the University of Port Harcourt Teaching Hospital, Nigeria.

Apgar scores of 200 newborns- 100 from mothers with HDP (case group) and 100 from normotensive mothers (control group)- were taken at 1st and 5th minute of birth and cord blood samples collected to determine hematocrit. The subjects were categorized into polycythemic and non polycythemic using a hematocrit ≥65%.

Eight percent of newborns of women with HDP had polycythemia while none of the controls did. Apgar scores in the case group with and without polycythemia at one-minute were 4.1±1.8 and 6.6±2.1, respectively and at 5 minutes were 6.9±1.7 and 8.5±1.4 respectively. Hematocrit correlated positively with Apgar scores (both at one and five minutes) in cases without polycythemia (r = 0.221, p = 0.034 and r = 0.255, p = 0.014). Hematocrit of polycythemic newborns did not correlate with Apgar scores (r = -0.287, p = 0.491 and r = -0.436, p = 0.281).

The incidence of polycythemia is significantly higher in newborns of women with HDP and these polycythemic neonates had a significantly higher incidence of birth asphyxia. Therefore, birth outcome as determined by Apgar score is influenced by hematocrit.