The success of IVF can be predicted by measuring the endometrial expression of leukaemia inhibitory factor (LIF) during the luteal phase of the menstrual cycle, Brazilian study findings indicate.
Paulo Serafini, from the University of São Paulo, and colleagues immunostained luteal phase endometrial biopsy specimens of 52 women due to undergo IVF. Standard protocols were used to perform embryo culture and transfer.
The median age of the women was 35 years. Immunostaining for LIF was weak in 5.8 percent, mild in 61.5 percent, and strong in 32.7 percent of samples. The average number of embryos transferred was three, and their cumulative quality score was 20.
In all, 39 percent of the women achieved clinical pregnancy following IVF. Strong endometrial LIF expression was significantly associated with pregnancy, such that women with strong expression were 6.4 times more likely to become pregnant than those with weaker expression.
Age was also associated with clinical pregnancy, with each 1-year increase in maternal age associated with a 30 percent decrease in the likelihood of becoming pregnant.
"Midluteal endometrial LIF expression can be assessed immunohistochemically and used both as a biomarker of adequate endometrial development and a predictor of IVF success," the team says.
