Embryo transfer day does not affect the initial maternal serum β-hCG levels: A retrospective cohort study

Single day 14 serum hCG values allow prediction of viable pregnancy and are significantly higher in frozen as compared to fresh single blastocyst transfer

PURPOSE

To evaluate if single serum human chorionic gonadotropin (hCG) level measurements are sufficient for pregnancy monitoring after single embryo transfer (sET) and to compare the hCG levels between fresh (FRET) and frozen embryo transfers (FET) in medically assisted reproduction.

METHODS

This was a retrospective exploratory cohort study including all patients who met the inclusion criteria, who received a single FRET (n = 249) or FET (n = 410) of a day five blastocyst at the IVF clinic at the Johannes Kepler University Linz between 2011 and 2020. hCG levels were measured on day 14 after embryo transfer. Threshold values for the viability of pregnancies were determined using receiver operating characteristic (ROC) curves.

RESULTS

Significantly higher hCG levels were found in those who received FET than in those who received FRET (1222.8 ± 946.7 mU/ml vs. 862.7 ± 572.9 mU/ml; p < 0.001). Optimal threshold values predicting a viable pregnancy were 368.5 mU/ml and 523 mU/ml in the FRET and FET groups, respectively.

CONCLUSIONS

After FET, higher hCG values after 14 days of embryo transfer must be considered in pregnancy monitoring. Additionally, a single threshold hCG value seems to be sufficient for determining pregnancy viability. To exclude ectopic pregnancies, subsequent ultrasound examination is a mandatory requirement.

Early β-hCG levels predict live birth after single embryo transfer

PURPOSE

Specific serum beta human chorionic gonadotropin (β-hCG) parameters that can predict live birth after an embryo transfer have yet to be defined.

METHODS

We performed a retrospective cohort study of 1,028 patients with a detectable β-hCG who underwent a single embryo transfer between 2002 and 2019 at a large academic center. Two β-hCG parameters were examined in relation to live birth: 1) "doubling" defined as β-hCG doubling over 48 h and 2) "reaching 100" defined as a β-hCG ≥ 100 mIU/mL by 15 days after oocyte retrieval (AOR).

RESULTS

One thousand three hundred forty cycles involving a single embryo were analyzed. Two thirds were frozen embryos and 86% were blastocyst transfers. Preimplantation genetic testing was performed in almost 30% of cycles. When β-hCG levels "doubled," a live birth occurred in 80.7% of cycles and when β-hCG levels "reached 100" by 15 days AOR, live birth occurred in 81.6% of cycles. When β-hCG levels both doubled and reached 100 by 15 days, AOR 85.4% cycles resulted in live birth. A multiple logistic regression model to control for patient and cycle level factors revealed a live birth odds ratio (OR) of 8.0 (95% CI 5.7-11.1) when β-hCG "doubled" and an OR of 21.2 (95% CI 14.3-31.5) when β-hCG "reached 100." When both these latter parameters were met, the OR was 12.5 (95% CI 8.9-17.8).

CONCLUSION

β-hCG parameters of "doubling" and "reaching 100" by 15 days AOR are robust predictors of live birth and can aid in patient counseling regarding pregnancy outcomes soon after single embryo transfer.

Early Serum hCG in IVF: Are We Trending in the Right Direction?

Human chorionic gonadotropin (hCG) measurements may be the earliest indicator of fertility cycle success, available several weeks before an ultrasound would be diagnostic for pregnancy. Outcomes of these cycles are high stakes for a couple, and the earliest reassurance of a normal pregnancy would be beneficial for their well-being. Additionally, earlier diagnosis can allow for more rapid management by providers in the case of abnormal pregnancies. Therefore, establishing normal values for initial hCG level and early hCG kinetics is of great interest. There are many factors involved in assisted reproductive techniques that may lead to alterations in hCG kinetics when compared with spontaneous pregnancies. We aim to characterize normal hCG values for in vitro fertilization (IVF) pregnancies and review how different aspects of the IVF process may alter these trends in order to establish how best to counsel patients during the waiting period.

What is the effect of embryo morphology on serum β-hCG levels?

OBJECTIVE

To determine the effect of embryonic factors on serum beta human chorionic gonadotropin (β-hCG) levels in pregnancy and live birth resulting after a single fresh cleavage embryo and blastocyst transfer.

STUDY DESIGN

This was a retrospective cohort study conducted at a tertiary care hospital. All fresh single embryo transfers (sETs) between September 2011 and December 2016 were included. The correlation analysis was performed to determine the association of embryo morphological parameters on mean serum β-hCG levels on day 12 after the transfer of a fresh single cleavage embryo and a fresh single blastocyst embryo.

RESULTS

Out of a total of 455 fresh sETs, 60 positive β-hCG results after the transfer of a single fresh cleavage-stage embryo and 82 after the transfer of a single fresh blastocyst. The mean β-hCG level resulting from a single fresh blastocyst ET was 371.7 ± 52.7 IU/L, which was similar to the mean β-hCG level resulting from a cleavage ET (314.5 ± 36.9 IU/L) (p = .70). Interestingly, serum β-hCG levels resulting from a single fresh blastocyst ET showed a correlation with day 5 blastocoele expansion, trophectoderm cell number and blastocyst quality score in ongoing pregnancy (r = .33, p = .02; r = .29, p = .04; and r = .31, p = .03, respectively). Moreover, day 5 blastocoele expansion and blastocyst quality score showed a correlation with the serum β-hCG levels resulting from a single fresh blastocyst ET in live birth (r = .36, p = .02; r = .31, p = .04, respectively).

CONCLUSION

Our study suggests that serum β-hCG levels resulting from a single fresh blastocyst ET showed a correlation with day 5 blastocoele expansion and blastocyst quality score in both ongoing pregnancy and live birth.