A 2026 study found that low β-hCG levels (≤50 mIU/mL at 9 days after blastocyst transfer) were linked to much lower live birth rates, and that how hCG rises over time is more predictive of outcome than the initial value.
hCG
A small 2025 study found that most pregnancies show detectable hCG by day 6 after a blastocyst transfer, and those that first become positive on day 8–10 have higher rates of biochemical and ectopic pregnancy and a lower chance of ongoing pregnancy.
A 2024 meta-analysis combined the results of 12 studies comparing different IVF trigger shots, including hCG, GnRH agonist, and dual and double triggers. Triggers showed variable outcomes, highlighting the need for a personalized medicine approach.
A 2024 study found that beta-hCG levels were related to day 3 and day 5 embryo quality and development, with blastocyst expansion having the strongest impact on both initial beta values and their doubling.
Researchers in a 2023 study developed a model to predict the chance of live birth after a positive β-hCG (beta-hCG), using the first measurement and a second one taken 48 hours later.
Researchers in a 2022 study found that women with low β-hCG (<149 mUI/ml) are more likely to have a preterm delivery and abnormal placental pathologies compared to women with higher β-hCG.
Researchers in a 2019 study compared pregnancy outcomes with different serum β-hCG levels that were measured on day 16 of the embryo’s age (13dp3dt/11dp5dt).