Influence of trophectoderm biopsy for preimplantation genetic testing in the serum level of first trimester biomarkers.

RESEARCH QUESTION: Does trophectoderm biopsy for preimplantation genetic testing for aneuploidies (PGT-A) affect maternal serum first-trimester pregnancy biomarkers (pregnancy-associated plasma protein A [PAPP-A], free β-HCG and placental growth factor [PIGF])?

DESIGN

Retrospective cohort study of all singleton pregnancies (n = 9794) after naturally conceived (n = 8005) IVF and fresh embryo transfers (n = 478), frozen embryo transfer of non PGT-A (FET) (n = 963) or PGT-A tested embryos (FET + PGT-A) (n = 348). Serum levels of free β-HCG and PAPP-A were measured in all women with a viable pregnancy at 8-13.6 weeks of pregnancy; PIGF was measured in 3784 women. Biomarkers were converted to a multiple of the expected normal median (MOM) for a pregnancy of the same gestational day. The medians for the multiple of the median were calculated and compared.

RESULTS

Free β-HCG did not differ according to mode of conception. The PAPP-A concentrations were significantly lower in IVF and fresh embryo transfers (-0.1 Log10 MOM raw PAPP-A) compared with FET + PGT-A (-0.04 Log 10 MOM raw PAPP-A, P = 0.009) and natural conceptions (-0.0187 Log 10 MOM raw PAPP-A) (P < 0.001). The PIGF levels were significantly lower in the FET + PGTA group versus natural conception (P = 0.001). Difference in means adjusted by crown rump length was 4.6 pg/ml (95% CI 2.7 to 6.6) for natural conceptions, 3.5 pg/ml (95% CI 0.34 to 6.6) for IVF and 2.2 pg/ml (95% CI 0.06 to 4.4) for FET.

CONCLUSION

Trophectoderm biopsy for PGT-A has a significant effect on first-trimester maternal serum PAPP-A and PIGF. This needs to be further validated, as it may mislead the estimation of the first-trimester risk of aneuploidies and pre-eclampsia.