The risk of having a preterm birth could be up to 3 times higher in patients with sickle cell disease (SCD), according to a study recently published in the American Journal of Obstetrics & Gynecology MFM.

“What previously may not have been considered is that impaired vascular perfusion in SCD will lead to maternal organ impairment and placental ischemia resulting in complications from SCD, and placental-mediated adverse pregnancy outcomes,” the authors wrote.

This retrospective study included 66 patients previously diagnosed with SCD who delivered a single neonate at more than 20 weeks gestation. Among the SCD cohort, all participants except 1 self-identified as Black. The authors used the overall population at Duke University Hospital (2594) in Durham, North Carolina, with the same inclusion criteria to compare data regarding labor between the groups.

The SCD patients exhibited a marked increase in preterm births, at 39.4%, compared to the control group, in which only 14.1% of deliveries were preterm.

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The majority (69.2%) of preterm births among the SCD cohort occurred due to medical indications, while only 30.8% were spontaneous. This ratio is almost exactly inverted in the overall Duke population, with 34.6% and 65.4% of preterm births being medically indicated and spontaneous, respectively.

The latter results translate into pregnant patients with SCD being twice as likely to have a medical indication for preterm labor when compared to the rest of the Black female population in the United States.

Most of the causes of medical indications for preterm labor are based on placental factors. Hypertensive disorders and fetal growth restriction were the most common causes, present in two-thirds of cases, followed by placental abruption and oligohydramnios.

These findings are expected since individuals with SCD have approximately twice the risk of developing preeclampsia, which correlates with the pathophysiology of SCD in which the endothelium is permanently dysfunctional.

“The same mechanisms that result in acute and chronic organ damage in SCD likely result in perinatal inflammation and placental ischemia, and the same therapies that decrease inflammation and improve perfusion in SCD, will likely improve pregnancy outcomes for both women with SCD and their unborn babies in the future,” the study authors concluded.


Fashakin V, Weber JM, Truong T, Craig A, Wheeler SM, James AH. Sickle cell disease and the incidence and etiology of preterm birth. Am J Obstet Gynecol MFM. Published online August 18, 2022. doi:10.1016/j.ajogmf.2022.100723