Thank you for your query.
Elevated maternal AFP puts the baby at high risk for neural tube defects and other abnormalities.
however, it is not confirmatory.
You should consult a Medical Genetics Specialist
who will take into account the combined risk ( after considering factors like maternal age, family history and many others ) and offer you the choice of invasive testing like Amniocentesis
to be sure.
Also , a detailed ultrasound
for fetal anomalies by a reputed person is a must.