For those without prophylactic therapy, as high as 91% of 136 pregnancies resulted in miscarriage.[sup] FXIII-A is present in normal uterus, implantation tissues, and placenta in normal pregnant women, but missing in women of congenital FXIII deficiency.[sup] Extravillous cytotrophoblasts formed the cytotrophoblastic shell which stabilized the interaction between embryo and decidua of uterus.
Maternal blood coagulation factor XIII is associated with the development of cytotrophoblastic shell. Placenta 2000;21:388-93.