Double digit MSAFP value in the second trimester of pregnancies: what does it really predict?

Maternal Serum Alpha-Fetoprotein (MSAFP) is the first maternal serum analyte identified in the 1970s and initially introduced as a screening tool for fetal Open Neural Tube Defects. Subsequently it has been shown to be associated with adverse pregnancy outcomes. Much research has been done over the years looking at maternal and fetal diagnosis, pregnancy complications as well as outcomes in pregnancies where MSAFP level during second trimester was >2.5 MoM. Because MSAFP levels >10 MoM is a rare finding not many publications address this specific group with the majority of the articles published around 30 years old. The aim of this study was to gain knowledge about maternal and fetal complications as well as the pregnancy outcome in this group of women. Out of all the women seen at Kaiser Permanente, Northern California for prenatal care between 2004 – 2014, 69 patients screened positive with MSAFP levels >10 MoM and complete records were available for 52 of those patients. In this cohort 28.8% of the patients received specific fetal diagnosis, 28.8% were found to have fetal abnormalities that did not lead to a specific diagnosis, 9.6% of pregnancies ended in fetal death before 24 weeks of gestation, live birth with pregnancy complications was seen in 17.3% and normal live birth without any complications was observed in 15.4% of pregnancies. These numbers should be interpreted with caution because of small number of women in the study but these findings carry important implications for counseling patients with highly elevated MSAFP levels.