Down syndrome maternal serum markers in oocyte donation and other assisted reproductive technologies

Because maternal serum markers (pregnancy-associated plasma protein A, human chorionic gonadotropin free β subunit, and alpha-fetoprotein) used for Down syndrome (DS) screening have been described as predictors of obstetrical complications and because assisted reproductive technology (ART) pregnancies are known to be at increased risk for obstetrical complications, it is unclear whether or not correction factors should be applied to the calculated risk of DS. The purpose of this study was to evaluate DS maternal serum markers in oocyte donation (OD) and ART pregnancies in comparison with natural pregnancies.

Multicenter retrospective 2010 to 2013 study in singleton pregnancies was used. First- and second-trimester DS screenings in 614 OD and 1921 ART pregnancies versus 7268 natural pregnancies are compared.

There was a significant increase in hCGβ in the OD group for both trimesters (first trimester: 1.28 MoM vs 1.02; P < .001 and second trimester: 1.32 MoM vs 1 MoM; P < .001). Pregnancy-associated plasma protein A was significantly lower in the ART group (0.92 and 1.02 MoM P < .001).

Maternal serum markers for DS screening are significantly modified in ART and OD pregnancies. Because these markers are also markers for obstetrical complications, the rationale for applying correction factors is questionable.