Predictive value of plasma human chorionic gonadotropin measured 14 days after Day-2 single embryo transfer

Association between the length of in vitro embryo culture, mode of ART, and the initial endogenous hCG rise in ongoing singleton pregnancies

STUDY QUESTION

Is there an association between the length of in vitro culture, mode of ART and the initial endogenous hCG rise, in cycles with a foetal heartbeat after single embryo transfer (ET) and implantation?

SUMMARY ANSWER

Both the length of in vitro culture and the mode of ART have an impact on the initial endogenous rise in hCG in singleton pregnancies.

WHAT IS KNOWN ALREADY

Different factors have been identified to alter the kinetics of hCG in pregnancies. Current studies show conflicting results regarding the kinetics of hCG after different types of ART (fresh vs frozen ET (FET)), the inclusion or not of preimplantation genetic testing (PGT), and the length of time in in vitro culture.

STUDY DESIGN, SIZE, DURATION

This was a multicentre cohort study, using prospectively collected data derived from 4938 women (5524 treatment cycles) undergoing IUI (cycles, n = 608) or ART (cycles, n = 4916) treatments, resulting a in singleton ongoing pregnancy verified by first-trimester ultrasound scan. Data were collected from the Danish Medical Data Centre, used by the three participating Danish public fertility clinics at Copenhagen University hospitals: Herlev Hospital, Hvidovre Hospital, and Rigshospitalet, from January 2014 to December 2021.

PARTICIPANTS/MATERIALS, SETTING, METHODS

The fresh ET cycles included cleavage-stage (2 or 3 days in vitro) and blastocyst (5 days in vitro) transfers. FET cycles included cleavage-stage (3 days in vitro before cryopreservation) or blastocyst (5 or 6 days in vitro before cryopreservation) transfers. The IUI cycles represented no time in vitro. To attain a comparable interval for serum-hCG (s-hCG), the ovulation induction time was identical: 35-37 h before oocyte retrieval or IUI. The conception day was considered as: the insemination day for pregnancies conceived after IUI, the oocyte retrieval day for fresh ET, or the transfer day minus 3 or 5 as appropriate for FET of Day 3 or 5 embryos. Multiple linear regression analysis was used, including days post-conception for the hCG measurement as a covariate, and was adjusted for the women's age, the cause of infertility, and the centre. For FET, a sensitivity analysis was used to adjust for endometrial preparation.

MAIN RESULTS AND THE ROLE OF CHANCE

The study totally includes 5524 cycles: 2395 FET cycles, 2521 fresh ET cycles, and 608 IUI cycles. Regarding the length of in vitro culture, with IUI as reference (for no time in in vitro culture), we found a significantly lower s-hCG in pregnancies achieved after fresh ET (cleavage-stage ET or blastocyst transfer). S-hCG was 18% (95% CI: 13-23%, P < 0.001) lower after fresh cleavage-stage ET, and 23% (95% CI: 18-28%, P < 0.001) lower after fresh blastocyst transfer compared to IUI. In FET cycles, s-hCG was significantly higher after blastocyst transfers compared to cleavage-stage FET, respectively, 26% (95% CI: 13-40%, P < 0.001) higher when cryopreserved on in vitro Day 5, and 14% (95% CI: 2-26%, P = 0.02) higher when cryopreserved on in vitro Day 6 as compared to Day 3. Regarding the ART treatment type, s-hCG after FET blastocyst transfer (Day 5 blastocysts) cycles was significantly higher, 33% (95% CI: 27-45%, P < 0.001), compared to fresh ET (Day 5 blastocyst), while there was no difference between cleavage-stage FET (Days 2 + 3) and fresh ET (Days 2 + 3). S-hCG was 12% (95% CI: 4-19%, 0.005) lower in PGT FET (Day 5 blastocysts) cycles as compared to FET cycles without PGT (Day 5 blastocysts).

LIMITATIONS, REASONS FOR CAUTION

The retrospective design is a limitation which introduces the risk of possible bias and confounders such as embryo score, parity, and ovarian stimulation.

WIDER IMPLICATIONS OF THE FINDINGS

This study elucidates how practices in medically assisted reproduction treatment are associated with the hCG kinetics, underlining a potential impact of in vitro culture length and mode of ART on the very early embryo development and implantation. The study provides clinicians knowledge that the type of ART used may be relevant to take into account when evaluating s-hCG for the prognosis of the pregnancy.

STUDY FUNDING/COMPETING INTEREST(S)

No funding was received for this study. AP has received consulting fees, research grants, or honoraria from the following companies: Preglem, Novo Nordisk, Ferring Pharmaceuticals, Gedeon Richter, Cryos, Merck A/S, and Organon. AZ has received grants and honoraria from Gedeon Richter. NLF has received grants from Gedeon Richter, Merck A/S, and Cryos. MLG has received honoraria fees or research grants from Gedeon Richter, Merck A/S, and Cooper Surgical. CB has received honoraria from Merck A/S. MB has received research grants and honoraria from IBSA. MPR, KM, and PVS all report no conflicts of interest.

TRIAL REGISTRATION NUMBER

The study was registered and approved by the Danish Protection Agency, Capital Region, Denmark (Journal-nr.: 21019857). No approval was required from the regional ethics committee according to Danish law.

m.4216 T > C polymorphism in JT cluster determines a lower pregnancy rate in response to controlled ovarian stimulation treatment

PURPOSE

To analyze the influence of Caucasian mitochondrial haplogroups on controlled ovarian stimulation outcome (COS), embryo (E), and pregnancy success.

METHODS

In a Caucasian population (n = 517) undergoing COS, mitochondrial haplogroups and physiological parameters were determined. Patients were classified, according to Bologna criteria, as good (>3)/poor ≤3) responder, on dependence of recruited oocytes (RO), and in pregnancy/non-pregnancy groups. Haplogroups were determined by sequencing mitochondrial hypervariable sequence I and confirmed by polymerase chain reaction (PCR), followed by restriction fragment length polymorphisms (RFLP).

RESULTS

The rank of total dose of FSH (TD FSH) was similar in all clusters/haplogroups, except in JT, which is narrower (950-3,650 IU), particularly in T (1,350-3,650 IU). The statistical analysis showed higher RO and E in JT when compared to U, although it was only Uk which accumulated significantly in pregnancy respect to JT. Pearson's correlations between TD FSH and RO showed negative statistical significance in all population (P = 0.001), H (P = 0.03), JT (P = 0.01), and T (P = 0.03). The percentage of contribution of TD FSH on RO was almost nine times in the JT cluster as compared to all population one.

CONCLUSIONS

JT cluster shows a different influence of TD FSH on RO. JT cluster shows higher RO and E than U, but it is Uk which exhibits a significant higher pregnancy rate than JT. The negative influence of the JT cluster on pregnancy success strongly suggests that the m.4216 T > C polymorphism could be responsible.

Klausen T, K. Danielsen A, Thomsen T, Bentin-Ley U, B. Knudsen U, Laursen S, R. Petersen M, Haahr K, Petersen K, Lemmen JG, Hindkjær J, Kirk J, Fedder J, J. Almind G, Hnida C, Troest B, B. Povlsen B, Zedeler A, Gabrielsen A, Larsen T, S. Kesmodel U. Is paternal age associated with transfer day, developmental stage, morphology, and initial hCG-rise of the competent blastocyst leading to live birth? A multicenter cohort study

In this study we investigated whether age of men undergoing assisted reproductive technology (ART) treatment was associated with day of transfer, stage, morphology, and initial hCG-rise of the competent blastocyst leading to a live birth? The design was a multicenter historical cohort study based on exposure (age) and outcome data (blastocyst stage and morphology and initial hCG-rise) from men whose partner underwent single blastocyst transfer resulting in singleton pregnancy/birth. The ART treatments were carried out at sixteen private and university-based public fertility clinics. We included 7246 men and women, who between 2014 and 2018 underwent controlled ovarian stimulation (COS) or Frozen-thawed Embryo Transfer (FET) with a single blastocyst transfer resulting in singleton pregnancy were identified. 4842 men with a partner giving birth were included, by linking data to the Danish Medical Birth Registry. We showed that the adjusted association between paternal age and transfer day in COS treatments was OR 1.06, 95% CI (1.00;1.13). Meaning that for every increase of one year, men had a 6% increased probability that the competent blastocyst was transferred on day 6 compared to day 5. Further we showed that the mean difference in hCG values when comparing paternal age group 30–34, 35–39 and 40–45 with the age group 25–29 in those receiving COS treatment, all showed significantly lower adjusted values for older men. In conclusion we hypothesize that the later transfer (day 6) in female partners of older men may be due to longer time spent by the oocyte to repair fragmented DNA of the sperm cells, which should be a focus of future research in men.

Association between 7-day serum β-hCG levels after frozen-thawed embryo transfer and pregnancy outcomes: a single-centre retrospective study from China

OBJECTIVE

Early monitoring of plasma human chorionic gonadotropin (β-hCG) level is vital in predicting pregnancy outcome. This study investigated the predictive value of serum β-hCG level on the seventh day after frozen-thawed embryo transfer (FET) for ongoing pregnancy (OP) and adverse pregnancy (AP).

DESIGN

Retrospective study.

SETTING

The Reproductive and Genetic Center of the Affiliated Hospital of Shandong University of Traditional Chinese Medicine, China.

PARTICIPANTS

1061 pregnant women who underwent FET between January 2014 and January 2017.

PRIMARY AND SECONDARY OUTCOME MEASURES

Pregnancy outcome.

RESULTS

Serum β-hCG levels on the seventh day after FET were higher in the single OP group compared with the biochemical pregnancy group (p<0.001). Besides, the serum β-hCG cut-off level at 4.34 mIU/mL on the seventh day showed high predictive value (area under the curve (AUC)=0.852). Serum β-hCG levels on the seventh day after FET were higher in the twin OP group compared with the single OP group (p<0.001). Also, the serum β-hCG cut-off level at 17.95 mIU/mL on the seventh day showed high predictive value (AUC=0.903). Serum β-hCG levels on the seventh day after FET were lower in the ectopic pregnancy group compared with the single OP group (p<0.001) whereas, serum β-hCG cut-off level at 4.53 mIU/mL on the seventh day exhibited a high predictive value (AUC=0.860). Further, the serum β-hCG levels on the seventh day after FET were lower in the single early spontaneous abortion group compared with the single OP group (p<0.001) while the serum β-hCG cut-off level at 5.34 mIU/mL on the seventh day exhibited high predictive value (AUC=0.738).

CONCLUSION

Serum β-hCG on the seventh day after FET has good clinical significance for the prediction of OP and AP.