Relationship between maternal serum alpha-fetoprotein and fetal middle cerebral artery peak systolic velocity in pregnancy with fetal anaemia

AIM: To evaluate the relationships between maternal serum alpha-fetoprotein (MSAFP) levels and middle cerebral artery peak systolic velocity (MCA-PSV) in pregnancies with fetal anaemia and to compare the sensitivities of MSAFP and MCA-PSV for the predicting the risk of fetal anaemia. METHODS: Fifty-five measurements of MSAFP and MCA-PSV were carried out in 32 women at risk of fetal anaemia (4 cases of alloimmunisation, 11 cases of thalassemia, 10 cases of parvovirus infection and 7 cases of placental chorioangioma). The relationship between MSAFP and MCA-PSV was studied, and 19 fetal blood samples, in which MCA-PSV measurements were abnormal, were taken and the fetal heamoglobin were tested in order to evaluate the correlation of MSAFP and MCA-PSV. RESULTS: A correlation between MSAFP and MCA-PSV (n=55, r=0.57, P<0.01) was observed, in which 15 cases of fetal anaemia and 4 cases false positive (non-anaemia) were detected among the 19 fetal blood samples. The MSAFP levels of 4 false-positive cases were normal. The MSAFP levels in 15 fetal anaemia cases were higher than those in non-anaemia. The elevation of MSAFP level was 15-20 d earlier than that of MCA-PSV in the cases of alloimmunisation and thalassemia, and it was 10-12 d later in the cases of parvovirus infection and placental chorioangioma significantly (P<0.05). Both MSAFP (r=-0.87) and MCA-PSV (r=-0.67) were significantly correlated with fetal heamoglobin level. CONCLUSION: The MSAFP level is significantly correlated with both MCA-PSV measurements and fetal haemoglobin. The time and process of the elevations of MSAFP indicate that MSAFP is more sensitive than MCA-PSV to predict and monitor the pregnancies at the risk of fetal anaemia.