Influence of Second-Trimester Ultrasound Markers for Down Syndrome in Pregnant Women of Advanced Maternal Age

Abstract EN

The objective of the present study was to evaluate the influence of second-trimester ultrasound markers on the incidence of Down syndrome among pregnant women of advanced maternal age.

This was a retrospective cohort study on 889 singleton pregnancies between the 14th and 30th weeks, with maternal age ≥ 35 years, which would undergo genetic amniocentesis.

The second-trimester ultrasound assessed the following markers: increased nuchal fold thickness, cardiac hyperechogenic focus, mild ventriculomegaly, choroid plexus cysts, uni- or bilateral renal pyelectasis, intestinal hyperechogenicity, single umbilical artery, short femur and humerus length, hand/foot alterations, structural fetal malformation, and congenital heart disease.

To investigate differences between the groups with and without markers, nonparametric tests consisting of the chi-square test or Fisher’s exact test were used.

Moreover, odds ratios with their respective 95% confidence intervals were calculated.

Out of the 889 pregnant women, 131 (17.3%) presented markers and 758 (82.7%) did not present markers on the second-trimester ultrasound.

Increased nuchal fold ( P < 0.001 ) and structural malformation ( P < 0.001 ) were the markers most associated with Down syndrome.

The presence of one marker increased the relative risk 10.5-fold, while the presence of two or more markers increased the risk 13.5-fold.

The presence of markers on the second-trimester ultrasound, especially thickened nuchal fold and structural malformation, increased the risk of Down syndrome among pregnant women with advanced maternal age.