Intravascular volume expansion and fetal outcome in pregnant Nigerians with hemoglobin SS and SC

Abstract

In a comparative study of physiological changes in pregnant Nigerians, plasma volume measurements were performed in 75 healthy Nigerian women. They comprised 40 women with hemoglobin genotype AA (20 pregnant and 20 nonpregnant) and 35 women with hemoglobin genotype SS or SC (15 pregnant and 20 nonpregnant). Plasma volume was determined in the left lateral position using the Evans blue dye dilution technique (described by Dacie and Lewis) in the nonpregnant, at 16 and 36 weeks of gestation, and at 8 weeks postpartum.The mean plasma volume of 2044 ± 77.4 mL (SEM) in normal nonpregnant women with Hb AA was not significantly different from the mean plasma volume of 1931 ± 115 mL (SEM) found in nonpregnant sicklers. At 16 weeks' gestation there was no significant difference in the mean plasma volume of 2712 ± 209.8 mL (SEM) in pregnant women with HB AA and 2948 ± 165.8 mL (SEM) in pregnant sicklers. However, at 36 weeks the mean plasma volume of 3440 ± 223.7 mL (SEM) (68 percent increase compared with nonpregnant) in pregnant women with Hb AA was significantly higher (P < .02) than the mean plasma volume of 2312 ± 214.8 mL (SEM) (17 percent increase compared with nonpregnant) in sicklers.The mean birthweight of 3.17 ± 0.08 kg (SEM) in women with Hb AA was higher (P < .01) than that of 2.58 ± 0.15 kg (SEM) in sicklers. The perinatal mortality in sicklers was 133/thousand total births, while there was no fetal loss in the control. These data suggest a decrease or lack of intravascular volume expansion and evidence of uteroplacental insufficiency in sicklers.