Results
There was a total of 9,096,788 deliveries documented between 2004 and 2015, inclusive. Out of those, 185 women had a documented diagnosis of Down syndrome. The prevalence of women with DS varied from 1.48 to 3.14 per 100,000 women during the study period (p-value <.001) (Figure 1).
The baseline maternal demographic and clinical characteristics of our study population are summarized in Table 1. Pregnant women with Down Syndrome, compared with the control group, were more likely to be black and to smoke or use drugs during the pregnancy (15.4% vs. 5.8%, 7.6% vs. 3.5% and 4.3% vs. 1.2% respectively). There were no significant differences between the two groups concerning age, income, or insurance plan. Patients with Down syndrome did not have a higher prevalence of pre-existing metabolic conditions including obesity, chronic hypertension, pregestational diabetes or thyroids disease and were not more likely to have a multiple gestation compared to the control group.
The association between DS in women and adverse pregnancy and delivery outcomes, while controlling for confounding variables, are outlined in Table 2. Women with Down syndrome did not have an increased risk of developing pregnancy induced hypertension, gestational hypertension, preeclampsia and gestational diabetes mellitus, compared to the control group. Down syndrome was not associated with adverse delivery outcomes including PPROM, chorioamnionitis, operative vaginal delivery, cesarean delivery, spontaneous vaginal delivery, postpartum hemorrhage, length of stay and transfusion. Women with Down syndrome were more likely to have a preterm delivery (aOR 3.86, 95% CI 1.25-11.93).
The association between pregnant women with DS and neonatal outcomes, while controlling for confounding variables, are outlined in Table 3. Our results demonstrate staggeringly increased risks of intrauterine fetal demise (aOR 20.97, 95% CI 1.86-237.02). Neonates born to women with Down syndrome are overwhelmingly more likely to be small for gestational age (aOR 13.13, 95% CI 2.20-78.41) and to have congenital anomalies (aOR 9.59, 95% CI 1.47-62.72).