Description
Background: In order to decrease the high rate of multiple gestation pregnancies following in vitro fertilization (IVF), elective transfer of a single embryo (eSET) in good prognosis patients has been proposed. The purpose of this dissertation is to evaluate the present efficacy of eSET policies and to investigate whether modifications to patient guidelines could better identify patients who should be targeted for eSET. Methods: De-identified patient records from a private fertility center were reviewed to identify patients who had undergone IVF from 2006 through 2012. Three analyses were undertaken: (1) Comparing the equivalency of pregnancy and live-birth rates between patients opting for single blastocyst transfer (eSBT) and double blastocyst transfer (eDBT), (2) Assessment of whether clinical factors associated with multiple gestation pregnancies could be identified by comparing multiple and singleton gestation cycles, and (3) Development of a predictive model for the probability of cycle failure among young patients, by examining patients younger than 35 who failed to achieve a live-birth and those who attained a live-birth. Results: No significant differences in pregnancy and live-birth rates were observed between the eSBT and eDBT groups, however, clinical equivalence was only demonstrated for pregnancy rates. Odds of multiple birth decreased as maternal age increased, whereas risk increased in cycles with a fertilization rate >80%, when embryos were transferred at the blastocyst stage, and when the second best embryo transferred was graded as "good". The most relevant early predictors of cycle failure among young patients were a history of previous preterm or full-term live-birth, biochemical pregnancies and spontaneous abortions, day 3 follicle stimulating hormone level, antral follicle count, and number of follicles larger than 14mm on the day of human chorionic gonadotropin administration. Conclusions: While we are moving in the right direction towards clinical efficacy in eSET, addressing potential gaps in clinical guidelines could further increase acceptability of the procedure. In considering both clinical patient factors and embryo cohort characteristics, a more comprehensive profile of patients best suited for eSET could be developed that would increase the successfulness of the procedure, while simultaneously decreasing the high rate of multiple gestation pregnancies seen in IVF.
