Prenatal screening at 11-13+6 weeks in assisted reproductive technology singleton pregnancies and those conceived naturally.

Aim To investigate whether assisted reproductive technology (ART) increases the risk of fetal chromosomal abnormalities. Methods A total of 2034 singleton pregnant women were included in this retrospective study. They were divided into ART (574 fetuses) and control groups (1460 fetuses conceived naturally). All pregnant women received screening according to the Fetal Medicine Foundation, London 2004 Kypros H. Nicolaides guidelines at 11–13+6 weeks of gestation. Accordingly, women with value at risk of chromosomal abnormalities >1:250 underwent chorionic villus sampling or amniocentesis. Results Mean body mass index was 22.83 ± 3.27 versus 21.29 ± 2.81 kg/m2 in the ART and control groups, respectively (P < 0.001). Mean maternal age was higher in the ART group (31.07 ± 4.30 vs 28.16 ± 3.99 years, P < 0.001). Crown–rump length (CRL) and biparietal diameter (BPD) were significantly higher in the ART group (P < 0.001), but free β-human chorionic gonadotropin and plasma protein-A MoM were similar between the groups. Interestingly, nuchal translucency thickness in the ART group was significantly higher than in the control group, but the difference disappeared at 13–13+6 weeks. Positive ultrasound screening rate was not significantly different. The prevalence of high risk (3.83% vs 3.83%) and that of abnormal karyotype (0.35% vs 0.21%) were similar. Conclusions Despite the negative factors associated with the infertile women themselves, ART did not seem to increase the risk of fetal chromosomal abnormalities. Additionally, fetus size in the ART group was bigger than that in the natural conception group.