Gestational age at abortion: the impact of first-trimester risk assessment for aneuploidy

The purpose of this study was to determine the impact of first-trimester risk assessment on gestational age at abortion for abnormal fetal karyotype.

Women who had abortion for trisomies 21, 18, and 13, 45X, and Triploidy in our hospital from 1999 to 2005 were included. Data collected included gestational age at abortion, method of prenatal diagnosis, and whether or not first-trimester risk assessment was performed. Analysis was performed using Spearman Correlation, Chi-square for trend, Fisher exact test, and Mann-Whitney U test.

One hundred forty-nine patients were included. There was an inverse correlation between year of abortion and gestational age (rho = -0.31; P < .001) coinciding with significant increases in the rates of first-trimester risk assessment and prenatal diagnosis by chronic villus sampling.

First-trimester risk assessment is associated with earlier diagnosis of aneuploidy. In our institution, this has led to earlier abortions. Availability of quality first-trimester risk assessment can decrease the need for abortion later in pregnancy.