Down syndrome screening at first-trimester may cause a higher false positive rate in pregnant patients who have undergone assisted reproductive technologies (ART). Combining the second largest series of biophysical and biochemical tests in the first trimester of pregnancy after ART is mentioned in few studies.
Materials and methods
Ghisoni et al explored that NT measurement between ART pregnancies and matched controls was not significantly different. PAPP-A was reduced but it was not significantly lower in ART pregnancies. Free beta- HCG and PAPP-A were measured on dried blood spots and converted to MoMs.
Nuchal translucency (NT) was measured by certified operators. Free beta-HCG was the only analyte that resulted in significantly higher values in ART pregnancies versus controls. No significant differences were found for biochemical values observed between ICSI and IVF patients. NT measurements were not affected by ART pregnancies. In another study that was performed in Italy, results were consistent with other reported series
The algorithm used to calculate the relative risk after the combined tests should not be changed until the detection rate of trisomies in ART pregnancies is not fully disclosed by larger series