Photo by Nina Matthews
Results of a new analysis may help physicians predict the likelihood of complications in pregnant women with sickle cell disease (SCD).
The research showed that pregnant women with SCD had an increased risk of stillbirth, pre-eclampsia, preterm delivery, having infants who were born small for their gestational age, and other adverse outcomes.
Women with severe SCD, but not those with milder SCD, had a substantially higher risk of mortality than their healthy peers.
Researchers reported these findings in Blood.
“While we know that women with sickle cell disease will have high-risk pregnancies, we have lacked the evidence that would allow us to confidently tell these patients how likely they are to experience one complication over another,” said study author Eugene Oteng-Ntim, MD, of the Guy’s and St. Thomas’ NHS Foundation Trust in London, England.
“This reality makes it difficult for us as care providers to properly counsel our sickle cell patients considering pregnancy.”
To better estimate pregnancy-related complications in women with SCD, Dr Oteng-Ntim and his colleagues examined 21 published observational studies.
The team analyzed data on 26,349 pregnant women with SCD and 26,151,746 pregnant women who shared attributes with the SCD population, such as ethnicity or location, but were otherwise healthy.
The researchers classified the SCD population based on genotype, including 1276 women with the classic form (HbSS genotype), 279 with a milder form (HbSC genotype), and 24,794 whose disease genotype was unreported (non-specified SCD).
Thirteen of the studies originated from high-income countries ($30,000 income per capita or greater), and the remaining were from low- to median-income countries.
Compared to women without SCD, patients with HbSS genotype had an increased risk of death, with a risk ratio (RR) of 5.98. Women with non-specified SCD had an increased risk of death as well, with an RR of 18.51. There was only 1 death among women who were known to have HbSC SCD.
There was an increased risk of stillbirth among women with SCD, compared to those without the disease. The RRs were 3.94 for HbSS disease, 1.78 for HbSC disease, and 3.49 for non-specified SCD.
The researchers found a significantly lower risk of maternal mortality (odds ratio [OR]=0.15) and stillbirth (OR=0.28) in SCD patients from countries with a gross national income of $30,000 or greater. But income had no significant impact on pre-eclampsia, preterm delivery, or infants being small for their gestational age.
Women with all types of SCD had an increase in the risk of pre-eclampsia, compared to healthy women. The RRs were 2.43 for HbSS disease, 2.03 for HbSC disease, and 2.06 for non-specified SCD.
Women with SCD also had an increased risk of preterm delivery. The RRs were 2.21 for HbSS disease, 1.45 for HbSC disease, and 1.59 for non-specified SCD.
And women with SCD were more likely to have infants who were born small for their gestational age. The RRs were 3.72 for HbSS disease, 1.98 for HbSC disease, and 2.23 for non-specified SCD.
Analyses revealed that genotype (HbSS vs HbSC) had a significant impact on stillbirth, preterm delivery, and small infants, but it did not appear to impact the risk of pre-eclampsia.
The researchers said this study provides useful estimates of the morbidity and mortality associated with SCD in pregnancy.
“By improving care providers’ ability to more accurately predict adverse outcomes, this analysis is a first step toward improving universal care for all who suffer from this disease,” Dr Oteng-Ntim concluded.
