Late trimester hydranencephaly associated with maternal exposure to methamphetamine

Acquired hydranencephaly diagnosed after a normal ultrasound examination is a rare finding in pregnancy. The etiology includes infections, bleeding diatheses, neoplasms and exposure to vasoconstrictive agents. Fetal hydranencephaly was discovered on a third trimester ultrasound examination after a normal examination a month earlier. The pregnant patient admitted to heavy use of crystal meth during the preceding month. Upon the finding of an acquired hydranencephaly, the clinician should have a high index of suspicion for maternal abuse of vasoconstrictive agents such as methamphetamine or cocaine.