472 G6PD deficiency is associated with decreased maternal serum Alpha-fetoprotein levels

Abstract

Glucose-6-phosphate dehydrogenase (G6PD) deficiency is an inherited X-linked recessive disorder, being the most common enzymatic defect of erythrocytes in humans. Since G6PD deficiency has been associated with metabolic comorbidities and placental dysfunction, we aimed to examine whether this disorder can affect the levels of maternal serum biochemical screening markers. For this retrospective study, we collected data of all pregnant women delivering in our medical center between January 2015 to December 2019. The inclusion criteria were any documentation of maternal serum biochemical screening markers: free beta-human chorionic gonadotropin (HCG), pregnancy-associated plasma protein A (PAPP-A), maternal serum alpha-fetoprotein (AFP), HCG and unconjugated estriol. Overall, 6,186 women with documented maternal serum biochemical screening markers were detected, 63 of these (1.0%) with G6PD deficiency. No difference in demographic or obstetrical characteristics was noted between G6PD-deficient women to the remaining cohort (including maternal age, body mass index, gestational age and birth weight). In G6PD-deficient women, significantly lower levels of maternal AFP were found compared to the remaining cohort (0.87±0.28 vs. 1.05±0.28 multiples of median, respectively, p<0.001, Table 1). In addition, marginally lower second trimester HCG levels were found in G6PD deficiency (1.0±0.58 vs. 1.15±0.69 multiples of median in the remaining cohort, p=0.07). Since the placenta plays a major role in HCG synthesis, as well as in transferring the fetal AFP to maternal circulation, the placental effects of G6PD deficiency may explain lower levels of these markers. As maternal serum AFP measurement serves as a screening tool for neural tube defects, as well as a component of biochemical screening for Down syndrome, G6PD status may affect the screening results. Thus, the findings of our study may be of great importance in prenatal surveillance, and should be further explored.