Maternal serum levels of angiogenic markers and markers of placentation in pregnancies conceived with fresh and vitrified-warmed blastocyst transfer

Abstract

The aim of the study was to compare the levels of angiogenic markers and markers of placentation between pregnancies conceived with fresh (ET) and vitrified-warmed blastocyst transfer (FET). Methods Women with singleton pregnancies resulting from fresh ET or FET during the period between 2013 and 2017 were included in this prospective observational study. Fresh ET was performed in a stimulated and FET in natural cycle. At 6-7 weeks of gestation, after ultrasound confirmation of a single gestational sac with a viable embryo, serum levels of free β-hCG, pregnancy-associated plasma protein A (PAPP-A), placental growth factor (PIGF) and fms-like tyrosine kinase (sFlt-1) were measured. Data on the patients' characteristics, pregnancy complications and outcomes were collected from a questionnaire and National Perinatal Information System of Slovenia. Results Among 211 pregnancies, 126 were achieved with fresh ET and 85 with FET. There were no significant differences in perinatal outcome, pregnancy complication and PIGF level between the fresh ET and FET group. Women achieving pregnancy with FET had significant higher levels of free β-hCG (40.20 ± 30.62 IU/L vs. 28.74 ± 23.52, p = 0.002), PAPP-A (0.09 ± 0.06 vs. 0.06 ± 0.05 IU/L, p = 0.004) and sFlt-1 (596.19 ± 283.06 vs. 436.53 ± 248.23 pg/L, p < 0.0001) compared to women having conceived with fresh ET. There were no significant differences in the levels of evaluated biomarkers between patients with different pregnancy outcomes and complications. Conclusion Levels of angiogenic markers and markers of placentation differ between pregnancies achieved with fresh ET and FET which may reflect altered implantation and early placentation with some forms of assisted reproductive technologies.

The expression of pregnancy-associated plasma protein-A (PAPP-A) in human blastocoel fluid–conditioned media: a proof of concept study

“…Some data suggest no difference in PAPP-A levels in pregnancies resulting from fresh embryo transfer (ET), FET, or spontaneous conception [30], and other studies have shown lower first trimester maternal serum PAPP-A levels in pregnancies conceived as a result of either fresh ET or FET as compared with spontaneous pregnancies [31][32][33][34][35][36][37], which may support the concept of suboptimal placentation leading to related pregnancy complications, particularly in cases of fresh embryo transfers. In a prospective observational study comparing levels of angiogenic markers and markers of early placentation in maternal serum among women who conceived via fresh versus frozen ET, women who achieved pregnancy via FET had higher serum levels of PAPP-A than those who achieved pregnancy via fresh ET, consistent with previous clinical data suggesting more favorable obstetric outcomes with FET than fresh ET [38]. Interestingly, one study showed no correlation between blastocyst morphology parameters and first trimester maternal serum PAPP-A levels in ongoing pregnancies, which were defined as pregnancies which progressed to at least beyond 13 weeks of gestation in that study [39].…”

Frozen blastocysts: Assessing the importance of day 5/day 6 blastocysts or blastocyst quality

“…Transferring blastocysts is therefore perceived as the best option for elective single-embryo transfer (eSET), by reducing the risk of multiple pregnancies (3,4) without compromising live birth rates. With advances in cryopreservation techniques, improved implantation rates have been achieved, and pregnancy rates after frozen embryo transfer (FET) are at least comparable with those after the transfer of fresh IVF embryos (5). How to select single-blastocyst transfer for FET to reduce the time to successful pregnancy is very important.…”