False-Positive Results in Pregnancy Screening for Aneuploidy

The screening of chromosomal aberrations is one of the most common methods during pregnancy although this test is occasionally false-positive.

In this case-control study, 252 mothers with false-positive (n=126) and -negative (n=126) tests were evaluated respectively. Demographic data during pregnancy and postpartum included maternal and neonatal complications, and finally, perinatal variables were compared between the two groups.

The mean age of the case group was significantly higher than that of the control group (P < 0.001). In addition, lower smoking history in the spouse (P = 0.01), higher prevalence of preeclampsia (P = 0.33) and proteinuria (P = 0.03), preterm infant (P = 0.01), and low birth weight (P = 0.04) were observed in this group as well. Eventually, the shorter height P = 0.004) and lower 5-minute Apgar score (P = 0.03) were found in infants.

In general, mothers with positive screening results showed a higher risk of preeclampsia and preterm labor in comparison with those with false-negative screening results.