Can biochemical pregnancy be determined 5 days after frozen-thawed embryo transfer?

OBJECTIVE: To study the predictive value of serum ß-hCG on day 5 after frozen-thawed embryo transfer (FET) to predict pregnancy outcomes and to establish cut-off values for very early biochemical pregnancy diagnosis. METHODS: This retrospective cohort study was performed at a private reproductive medicine centre and we reviewed the medical records of women who underwent FET cycles from January 2018 to June 2019. A total of 116 evaluated cycles had serum ß-hCG levels measured on days 5 and 10 after FET. The predictive value of serum ß-hCG levels measured on day 5 after FET was investigated for very early biochemical pregnancy diagnosis. RESULTS: The standard biochemical pregnancy diagnosis was defined as a ß-hCG ≥25 IU/L on day 10 after FET. We then generated a receiver operating characteristic curve, and the cut-off value of ß-hCG on day 5 for predicting biochemical pregnancies was 4.0 IU/L, with 93.4% sensitivity and 92.7% specificity (AUC, 0.960; 95% confidence interval, 0.923-0.997). CONCLUSIONS: Values for ß-hCG at day 5 after FET ≥4.0IU/L are accurate for the diagnosis of biochemical pregnancy. The use of very early biochemical pregnancy diagnosis in clinical practice enables earlier management, patient counselling, and appropriate follow-up.

Monozygotic dichorionic-diamniotic twin pregnancy after single embryo transfer at blastocyst stage: a case report.

Single embryo transfer is highly encouraged on in vitro fertilization due to its lower rates of multiple pregnancy. Nevertheless, the likelihood of multiple pregnancy is higher when using assisted reproductive technology, probably because of embryo handling. Timing is crucial in the post-fertilization division of a single embryo to establish the amniocity and chorionicity of the gestation. In the case reported a 38 year-old woman, nulligravid, had a single blastocyst implanted, which resulted in monozygotic dichorionic-diamniotic twins. Despite being rare, there are reports of similar cases questioning the current knowledge on time of embryo division and the impact of assisted reproduction.