HCG level after embryo transfer as a prognostic indicator of pregnancy finished with delivery

Objective: To examine patients after embryo transfer for predictive influence of the human chorionic gonadotropin (hCG) level on the probability of finishing pregnancy with delivery.

Design: Retrospective study.

Setting: Fertimed, Fertility Treatment Centre, Olomouc.

Methods: 490 patients pregnant after IVF + ET treat-ment placed in the study. The influence of other factors: age (patients 20-50), number of transferred embryos (one, two and more) and the length of cultivation on the probability of finishing pregnancy with delivery or loss and the possibility to predict multiple pregnancy was also related to the known hCG value. The transferred embryos were divided into two groups - early (cultivation 48 and 72 hrs) and prolonged cultivation (PC 96 and 120 hrs). The answer here, therefore, is a multinomial variable with four levels. For that reason the data was analysed through a multinomial logistic model vs. multinomial distribution of a mistake and generalised logistic link function.

Results: The hCG level grows exponentially in the course of the 9th to 17th day after an embryo transfer (ET). The probability of one child delivery after the transfer of one embryo overdue after prolonged cultivation (96 or 120 hrs) grows with the average and above-average hCG values on the day of the draw. The hCG value was 678 (564-815) IU/l1 on the 14th day after ET in pregnancy ended in delivery, 321 (216-477) IU/l on average in abortion, 82 (51-132) IU/l in biochemical pregnancy and 1070 (737-1554) IU/l in multiple pregnancy. The probability of multiple pregnancy increased with hCG values greatly above the average and on the other hand, below-average values indicated abortion or biochemical pregnancy. The patients age was not proven to be of significant influence, the hCG level slightly decreased with higher age. On the contrary, an increasing frequency of abortions depending on the increasing age of the mother was once again confirmed.

Conclusion: The measured hCG values are considerably different depending on the pregnancy result, which is why this value is considered a quality predictive factor of the pregnancy result.