Comparison of in vitro fertilization cycles stimulated with 20 mg letrozole daily versus high-dose gonadotropins in Rotterdam Consensus ultra-poor responders: A proof of concept.

OBJECTIVE: To evaluate if high-dose letrozole can be used successfully to stimulate poor responders for in vitro fertilization (IVF). METHODS: This was a retrospective study conducted at a university hospital reproductive center. The analysis included women who were up to 42 years of age and were Rotterdam Consensus poor responders. A total of 247 patients received gonadotropins (300-450 IU daily) and 62 patients were stimulated with letrozole (20 mg daily) as part of an antagonist IVF protocol. RESULTS: The use of 20 mg of letrozole decreased the total dose of gonadotropins used (645 ± 175 IU vs. 5360 ± 1028 IU, P = 0.001) and resulted in lower costs of stimulation medications ($ 555.56 ± $ 150 vs. $ 4616 ± $ 885 Canadian Dollars; P = 0.001). Pregnancy per cycle (14.5%) and per transfer (16%) rates were legitimate for this low prognosis group and may have been better than or similar to those with high-dose gonadotropins. The rate of cycle cancellation may have been reduced in the letrozole versus gonadotropin group (11% vs. 38%; P = 0.001). CONCLUSION: Letrozole (20 mg daily) may be used to reduce the cost of ovarian stimulation in ultra-poor responders, significantly reducing the cost of the IVF cycle with probably at least similar outcomes to high-dose gonadotropins.

Blastocyst morphology has no relationship with serum ß-hCG levels and live birth rates once pregnant.

OBJECTIVE: What is the role of blastocyst morphology on day16 ß-hCG serum levels and pregnancy outcomes among patients who conceived through IVF cycles with single fresh Gardner's scored blastocyst transfers. STUDY DESIGN: A retrospective cohort study conducted at a single academic fertility center between January 2013 and December 2017. A total of 643 pregnancies were included in the study. RESULTS: The patients were divided into 5 groups according to Gardner's blastocysts grade of the ICM and the TE (grade), and into 4 groups according to blastocyst Gardner's degree of blastocoel expansion (stage). No significant differences were found between the different morphologic groups and day16 ß-hCG serum levels, clinical pregnancy rates and live births. A weak significant correlation was observed between Gardner's blastocysts grade and day 16 ß-hCG (Correlation Coefficient r= -0.098, p = .014) this correlation remained significant after controlling for confounders. (r= -0.099 p = . 013). A weak significant correlation was observed between Gardner's stage and day 16 ß-hCG (Correlation Coefficient r = 0.086, p = 0.029) this correlation lost significance after controlling for confounders. (r = 0.055, p = 0.340). When evaluating predictors of live birth using multivariate logistic regression, blastocyst grade (p = 0.33) and stage (p = 0.65), at transfer, were not associated with live births, when controlling for confounding effects. CONCLUSION: Once the patient conceives after IVF with single blastocyst, none of the morphological parameters have a strong impact on the day16 serum level of ß-hCG. Among women who conceived, blastocyst grade and stage were not associated with live births.

Revisiting serum ß-hCG cut-off levels and pregnancy outcomes using single embryo transfer.

PURPOSE: The objective of this study is to identify the pregnancy outcomes based on day-16 ß-hCG level assessed with modern assays, in fresh single embryo transfers. METHODS: A retrospective cohort study at a single academic center between 2013 and 2017. A total of 1076 pregnancies were included. RESULTS: Pregnancies were divided into 10% groupings of 107-108 patients each. The 10 groups did not differ for baseline characteristics. There was no difference on outcomes based on cleavage or blastocyst transfer. At a serum ß-hCG level of 103 ± 13 (range 74-135), 50% had a biochemical loss. Biochemical pregnancy losses remained 21% at serum ß-hCG range (136-197). It was only once serum ß-hCG level reached 199-252 that the probability of a biochemical pregnancy loss was 12%. Interestingly, if a clinical pregnancy is present even at low day-16 serum ß-hCG levels, the likelihood of live birth is approximately 50%. This maximizes to 75% when the serum ß-hCG level was at least 253 IU/L. The relationship between serum day-16 ß-hCG levels and clinical pregnancy or live birth is quite strong with correlation coefficients above 0.8 which accounted for more than 75% of the variability in outcomes in both cases. Receiver operator curves determined that the cut-off for a clinical pregnancy was 190 and for live birth, it was 213 IU/L. CONCLUSION: An increase in the serum ß-hCG levels at which to expect a reassuring outcome is required based on modern assays, as compared with the old cut-off levels.

Pregnancy of Unknown Location: A Survey-Based Evaluation of When and Why Physicians Intervene?

INTRODUCTION: Management of pregnancies of unknown location (PUL) is a complex challenging clinical situation with possibilities for pitfalls. Obstetricians and gynaecologists of varied levels of training and experience from Canada and the Nordic countries were questioned about their approach when faced with PUL. METHOD: A 13-item web-based questionnaire was used to evaluate physicians' behaviors by surveying their management of a PUL encountered at different levels of human chorionic gonadotropin (hCG). They were queried regarding the level of hCG at which they would take management action in an asymptomatic PUL, in a given scenario. RESULTS: Three hundred fifty three questionnaires were completed resulting in a response rate, representing completeness of the survey, of 78.6%. Three distinct hCG thresholds, at which intervention to interrupt a PUL would be considered, dominated the responses. Thirty seven percent of physicians would intervene at hCG levels between 1000-3000 IU, 22% selected the 4000-6000 IU range, and 13% would only intervene if the hCG level exceeded 10 000 IU. These ranges were similar across different levels of clinical experience. In addition to hCG values, a patient's desire to keep the pregnancy, the development of new symptoms, and the expected gestational age were the other principal factors influencing the decision to intervene. CONCLUSION: There appears to be little consensus regarding the hCG threshold at which medical intervention should be initiated in an asymptomatic pregnancy of unknown location and further studies to justify earlier or later intervention are needed to determine the appropriate time for intervention.