Does first-trimester serum pregnancy-associated plasma protein A differ in pregnant women with sickle cell disease?

To assess whether levels of first-trimester pregnancy-associated plasma protein A (PAPP-A) differ between women with and without sickle cell disease (SCD).

Retrospective study of 101 singleton pregnancies in women with SCD (including 55 with genotype HbSS, 37 with genotype HbSC, and nine with other genotypes). Measured levels of PAPP-A were converted to multiple of the median (MoM) values corrected for gestational age and maternal characteristics. Median PAPP-A MoM in the SCD group was compared with that of 1010 controls.

In the SCD group median, PAPP-A MoM was lower than in the non-SCD group (0.72, interquartile range [IQR] = 0.54-1.14 versus 1.09, IQR = 0.74-1.49; P < .001). Within the SCD group median PAPP-A MoM was lower for those with genotype HbSS than HbSC (0.62, IQR = 0.44-1.14 versus 0.94, IQR = 0.72-1.25; .006). In 7.3% (4/55) of the HbSS group, there was stillbirth, and in these cases, PAPP-A was less than or equal to 0.5 MoM; in the control group, the incidence of stillbirth was lower (1%; P < .001). In HbSS disease, the incidence of small for gestational age (SGA) neonates was increased.

Pregnancies with HbSS have lower PAPP-A MoM values and higher incidence of stillbirth and birth of SGA neonates than in non-SCD controls.