CD40LG and anemia: In contrast, an estimated fetal weight of 1149 g (-0.6 SD), a maximal vertical pocket of 4.8 cm, no fetal ascites, no subcutaneous edema, and MCA-PSV of 38.7 cm/s (1.0 MoM) were observed in twin B. No morphological malformations were detected in either fetus. Maternal blood tests were found to be negative for irregular antibodies, HbF was 0.4 %, parvovirus B19 IgM was negative, and cytomegalovirus IgM was negative, indicating that no maternal factors could induce fetal anemia.