Pregnancy outcomes following false-positive multiple marker screening tests

Area of Science:

• Maternal-Fetal Medicine
• Prenatal Screening
• Genetics

Background:

• Midtrimester multiple marker screening tests (MMST) are used to assess fetal aneuploidy risk.
• False-positive MMST results can cause significant patient anxiety.
• The impact of false-positive MMST on pregnancy outcomes in older women requires clarification.

Purpose of the Study:

• To evaluate pregnancy outcomes in women aged 30 and above with a false-positive MMST and normal midtrimester ultrasound.
• To compare adverse pregnancy outcomes between women with positive and negative MMST results.

Main Methods:

• Retrospective review of a genetic database for women aged >= 30 undergoing MMST, targeted ultrasound, and amniocentesis.
• Exclusion of cases with abnormal fetal ultrasound or karyotype.
• Comparison of adverse outcomes (fetal death, preterm delivery, low birth weight) between false-positive MMST and control groups using statistical analysis.

Main Results:

• No significant differences in fetal death (0.4% vs 1.3%), preterm delivery (13.0% vs 16.5%), or birth weight <10th percentile (3.7% vs 3.4%) were observed between groups.
• The study included 1135 women, with 22% having a positive MMST; 77% were over 35 years old.
• Statistical analysis (Chi-square, Fisher's exact tests) did not reveal significant outcome disparities.

Conclusions:

• Women aged 30 and above with a false-positive MMST and a normal midtrimester sonogram do not face increased risks for adverse pregnancy outcomes.
• Normal midtrimester obstetrical sonography is a key factor in reassuring patients with false-positive MMST results.
• These findings support a more nuanced approach to managing false-positive screening results in older pregnant individuals.