Pregnancy Complications In Sickle Cell Disease Are More Prevalent In Women with Vaso-Occlusion Related Organ Damage Than Hemolysis Related Organ Damage

Patients with sickle cell disease (SCD) develop accumulating organ damage throughout their lives as result of chronic hemolytic anemia and ongoing microvascular vaso-occlusion. Chronic organ damage has been related to significant morbidity and increased mortality. Previous studies have shown significant increased foetal and maternal complications in patients with SCD. It is unclear whether the presence of chronic organ damage is related to pregnancy complications in these patients. Therefore, we determined the relation between chronic organ damage and pregnancy complications in women with SCD.

We performed a retrospective analysis of pregnancy complications in all women known with SCD (defined as HbSS, HbS-β°, HbSC and HbSβ⁺) in a teaching hospital in the Netherlands. Pregnancy complications consisted of: hypertension, (pre)eclampsia, still birth, preterm birth, dysmaturity, urinary tract infection, perinatal mortality, maternal mortality, painful crisis and acute chest syndrome (ACS). In all patients vaso-occlusion related organ damage (pain rate >1 crises/year, ACS, avascular osteonecrosis and retinopathy) as well as hemolysis related organ damage (microalbuminuria, renal failure, pulmonary hypertension, chronic leg ulcers, stroke and cholelithiasis) was assessed. The patients were divided in a severe (HbSS/HbSβ°) and a mild genotype group (HbSC/HbSβ⁺). Chronic organ damage and the history of previous sickle cell-related complications were related to pregnancy complications, birth weight and laboratory tests. We adjusted for multiple pregnancies with the generalized estimated equations (GEE) model.

All 97 female patients known with SCD in our hospital were systematically evaluated for organ damage and sickle cell related complications. Thirty-six patients had not been pregnant at time of evaluation, medical information about their pregnancy was missing for 7 women and 6 women were only known with an elective abortion. Fifty-five pregnancies in 48 women with SCD (18 HbSS, 4 HbSβ⁰, 21 HbSC and 5 HbSβ⁺) were evaluated for pregnancy complications. Hemolysis related organ damage was present in 17/22 (77%) of the patients with a severe genotype and 7/32 (22%) patients with a mild genotype (p<0.001). Patients with vaso-occlusion related organ damage had more pregnancy related complications 26/32 (81%) compared to patients without vaso-occlusive related organ damage 10/19, (53%) (p=0.033). No relation between hemolysis related organ damage and pregnancy complications was found. In the severe genotype group more pregnancy complications were observed and children of patients with the severe genotype had a lower birth weight (2603±721) as compared to the milder group (2866±811) but these differences did not reach significance. Lower birth weight correlated with lower hemoglobin concentration (Hb) (r=0,326; p=0.08), leukocyte count (r=−0.438; p=0.005) and platelet counts (r=-0.368; p<0.001). With respect to laboratory test, patients with pregnancy complications had lower hemoglobin levels (p=0.031), higher leukocyte counts (p=0.006) and a lower LDH (p=0.049) in comparison to patients without any pregnancy complication.

The majority of patients with SCD had at least one pregnancy complication. Pregnancy related complications were more frequently observed in patients with organ complications related to vaso-occlusion than patients with mainly hemolysis related complications. Furthermore, pregnancy related complications were more frequently observed in the severe genotype group with a trend to a lower birth weight and appeared to be related with lower Hb concentration, higher leukocyte and higher platelet counts.

No relevant conflicts of interest to declare.