Possibility of live birth in patients with low serum β-hCG 14 days after blastocyst transfer

Abstract

Background Although prior work has attempted to predict pregnancy outcomes by assaying serum β-hCG levels after blastocyst transfer, no study has focused on pregnancy outcomes in those with initially low serum β-hCG levels. This study sought to investigate pregnancy outcomes of patients with low serum β-hCG levels 14 days after blastocyst transfer. Methods A retrospective study was conducted at the Third Affiliated Hospital of Guangzhou Medical University to study patients whose serum β-hCG levels were at 5–299 mIU/ml 14 days after frozen blastocyst transfer. Rates of live birth, early miscarriage, biochemical pregnancy loss and ectopic pregnancy were analyzed according to the female patients’ age by Chi-squared analysis. Receiver operating characteristic (ROC) curves were plotted to explore the threshold of predicting clinical pregnancy and live births. Results 312 patients had serum β-hCG levels < 300 mIU/ml at 14 days after frozen blastocyst transfer, among which, 18.6% were live births, 47.4% were early miscarriages, 22.8% were biochemical pregnancies and 9.6% were ectopic pregnancies. ROC curve analysis showed that a predicted value of β-hCG for clinical pregnancy was 58.8 mIU/ml with an area under the ROC curve (AUC) of 0.752, a sensitivity of 95.0% and specificity of 53.5%. The threshold for live births was 108.6 mIU/ml with an AUC of 0.649, a sensitivity of 93.1% and a specificity of 37.0%. For the β-hCG fold increase over 48 h, the cut-off for clinical pregnancy was 1.4 with an AUC of 0.899, a sensitivity of 90.3% and a specificity of 77.8%. The threshold for live birth was 1.9 with an AUC of 0.808, a sensitivity of 88.5% and specificity of 64.5%. Conclusions Initially low serum β-hCG levels 14 days after frozen blastocyst transfer indicated minimal chances of live birth. For patients having an initial β-hCG > 58.8 mIU/ml, luteal phase support should continue. Another serum β-hCG test and ultrasound should be performed one week later. When an initial serum β-hCG is < 58.8 mIU/ml, luteal phase support should be discontinued and serum β-hCG measured with ultrasound one week later.

Primary omental ectopic pregnancy after frozen-thawed single embryo transfer: A case report and review of the literature

“…This study demonstrated that the minimum (1st percentile) rise in βhCG over 48 hours in viable intrauterine pregnancies is 49%, 40%, and 33% for initial βhCG values of <1,500, 1,500-3,000, and >3,000 IU/L, respectively [15]. This suggests that the traditional teaching that βhCG values should double every 48 hours in early pregnancy may be too strict [16]. Based on these criteria, our case of a primary omental ectopic pregnancy did meet the minimum expected rise in βhCG for a viable intrauterine pregnancy.…”

Prognostic value of a serum β-hCG cut off, 12 days after fresh embryo transfer, on predicting live birth among Ugandan women

“…Importantly, these cut off values are not absolute and are to be interpreted with caution since, the lowest cut off, corresponding to the 5%centile, was 264.81 mIU/ml. This was echoed by Y Wu and H Liu [53], were optimal cut offs as low as 108.6 mIU/ml predicting live birth albeit with a false positive rate over > 50%.…”

Prognostic value of a serum β-human chorionic gonadotropin cutoff, twelve days after fresh embryo transfer, on predicting live birth among Ugandan women

“…Importantly, these cutoff values are not absolute and are to be interpreted with caution since, the lowest cutoff, corresponding to the 5 percentile, was 264.81 mIU/ mL. This was echoed by Wu and Liu [51] , where optimal cutoffs as low as 108.6 mIU/mL predicting live birth albeit with a false positive rate over > 50%.…”