Human trophoblast cell during first trimester after IVF-ET differs from natural conceived pregnancy in development and function.

OBJECTIVE To explore the differences of the trophoblast cell function in first trimester between natural pregnancy and pregnancy after IVF-ET therapy. METHODS 102 cases with twin to singleton fetal reduction after IVF-ET treatment from July 2010 to August 2013 in Peking University Third Hospital were involved in analysis, and eight specimens were obtained from this group. 10 natural-pregnancy cases undergoing artificial abortion with unwanted pregnancy were recruited as control. Semi-quantitative immunohistochemical method was used to detect the expression of EGFR, Bcl-2, tubulin-α, metallothionein and AFP in villi in both groups. RESULTS Of the 102 cases, 14 cases (13.73%) were aborted. Preterm birth occurred in seven cases (7.86%). Low birth weight occurred in three patients (3.37%), and extremely low birth weight occurred in four cases (4.49%). The expression of EGFR, tubulin-α, Bcl-2, and metallothionein in the IVF-ET group was significantly lower than that in the control group (P<0.05). However, AFP expression was significantly higher in IVF-ET group than in control group (P<0.05). In IVF-ET group, the miscarriage case had weaker EGFR, tubulin-α, and metallothionein expression than full-term pregnancy; the early preterm labor case had weaker Bcl-2, tubulin-α, and metallothionein expression; and velamentous cord insertion case had weaker tubulin-α expression. CONCLUSIONS The trophoblast cell function of IVF-ET group in first trimester is different from control group in proliferation, invasion, apoptosis and vascular development, and optimal pregnancy outcome depends on the self-healing balance of trophoblast cells.