Outcomes and Management of Pregnancies Screening Positive for Microdeletions 22q11.2, 15q11.2, 1p36, 4p, or 5p: A...

To compare pregnancy outcomes and management between patients screening positive for five microdeletions (microdeletion screen-positive, MDS+) and patients screening negative (microdeletion screen-negative, MDS-).

Patients who received a prenatal cell-free DNA (pcfDNA) test that screens for microdeletions 22q11.2, 15q11.2, 1p36, 4p, and 5p and results were linked to de-identified insurance claims. Diagnosis and procedure codes were used to assess outcomes. Logistic and Poisson regression with adjustment for prior high-risk pregnancy and payer type were used to compare pregnancy outcomes and management in those with MDS+ and MDS- results.

A total of 119 MDS+ patients and 287,169 MDS- patients were eligible for analysis. During pregnancy, MDS+ patients were more likely than MDS- patients to have polyhydramnios (18.5% in MDS+ vs. 3.4% in MDS-; OR=6.3 [95% CI: 3.8-10.1]; p<0.001) and fetal growth restriction (22.2% in MDS+ vs. 10.4% in MDS-; OR=2.4 [95% CI: 1.5-3.7]; p<0.001). MDS+ patients were more likely to experience pregnancy loss (OR=3.2; 95% CI: 1.3-6.3; p=0.004) or terminate the pregnancy (OR=22.2 [95% CI: 8.6-46.8]; p<0.001). Among patients with a live birth, MDS+ were more likely to have a preterm delivery (25.0% in MDS+ vs. 15.4% in MDS-; OR=1.8 [95% CI: 1.0-3.0]; p=0.04). MDS+ patients had increased pregnancy management, including more invasive diagnostic testing (13.4% in MDS+ vs. 0.5% in MDS-; OR=31.0 [95% CI: 17.5-51.1]; p<0.001) and more frequent echocardiograms (RR=1.5 [95% CI: 1.2, 1.9]; p<0.001) compared to MDS- pregnancies.

MDS+ pregnancies had elevated rates of ultrasound abnormalities, pregnancy loss, preterm birth, and pregnancy management as compared to an MDS- control group. These findings support the clinical utility of microdeletion screening in prenatal care.