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Human Blastocyst Biopsy and Vitrification
Published on: July 26, 2019
Relationship between trophectoderm re-biopsy and serum beta-HCG levels in early pregnancies
Rebecca Zhuo1, Tamar Alkon-Meadows2, Samantha L Estevez1
1Icahn School of Medicine at Mount Sinai, New York, NY, USA.
Research Question:
Is trophectoderm re-biopsy for pre-implantation genetic testing for aneuploidy associated with lower serum beta-HCG (β-HCG) levels in early pregnancies resulting in live births?
Design:
Retrospective cohort study (n = 280) of patients who underwent single frozen embryo transfer (FET) with a resulting live birth. β-HCG was measured on days 9 and 11 after FET. Covariate-based matching was carried out in a 1:3 ratio: re-biopsy (n = 40); single biopsy (n = 120); and no biopsy (n = 120). To evaluate pregnancy outcomes, all patients who transferred a re-biopsied embryo were included and matched in a 1:3 ratio: re-biopsy (n = 320); single biopsy (n = 960); and no biopsy (n = 960).
Results:
On day 9 after FET, the re-biopsy group had significantly lower mean β-HCG (111.4 ± 69.0 mIU/ml) compared with the single biopsy (149.6 ± 70.2 mIU/m; P =0.011) and no biopsy (152.5 ± 80.3 mIU/ml, P = 0.008. On day 11 after FET, re-biopsy had significantly lower mean β-HCG (221.2 ± 208.7 mIU/m) compared with single biopsy (433.6 ± 246.0 mIU/ml) and no biopsy (448.6 ± 230.0 mIU/ml) (P < 0.001, both). The percentage increase in β-HCG from day 9 to 11 was significantly lower in re-biopsy (98.6%) compared with single biopsy (189.8%, P = 0.015) and no biopsy (194.2%, P = 0.008), but similar between single biopsy and no biopsy. Perinatal outcomes were similar among all groups. Positive pregnancy test, clinical pregnancy and live birth rates were lower in re-biopsy compared with single biopsy (65.6% [210/320] versus 75.7% [727/960], P < 0.001; 55.0% [176/320] versus 65.1% [625/690], P = 0.002; 43.8% [140/320] versus 53.8% [516/960], P = 0.002, respectively), but similar between re-biopsy and no biopsy.
Conclusions:
Trophectoderm re-biopsy was associated with significantly lower β-HCG in early pregnancies resulting in live births without corresponding differences in perinatal outcomes. These findings suggest that β-HCG levels after re-biopsied FET may require contextual interpretation, as lower levels do not necessarily reflect a compromised prognosis.
