A 34 years-old woman was referred to genetic counseling due to extremely high maternal serum alpha fetoprotein (MSAFP) of 58 MoM (541 IU/mL, 654 ng/mL) in the second trimester biochemical test. The couple has five healthy children, three of them were delivered by cesarean section. Current pregnancy follow-up was uneventful except for the demonstration of placenta percreta during anomaly scan. The test also ruled out neural tube or abdominal wall defect. AFP levels in amniotic fluid were normal thus fetal disease was ruled out as the etiology. Total body MRI ruled out space occupying lesion as a source of ectopic secretion of AFP. After exclusion of other ominous etiologies for this extremely high MSAFP, it was related to the placental pathology and probably to abnormal feto-maternal shunts. Fetal fraction in cell free DNA was 18%, considered relatively high, a hint for those speculated shunts. We reviewed the literature regarding the differential diagnosis of high MSAFP including fetal, maternal and placental sources.