Objective: To determine the antenatal and short-term neonatal outcome of antenatally detected congenital cystic adenomatoid malformation (CCAM).

Methods: A retrospective review was conducted on all women with an antenatal diagnosis of CCAM who attended the Royal Women's Hospital, Melbourne, between January 1995 and December 2005.

Results: An antenatal diagnosis of CCAM was made in 38 singleton pregnancies. Serial ultrasounds were performed in 34 cases. Thirteen lesions (38%) appeared to resolve, ten lesions (29%) appeared to decrease, four lesions (12%) appeared to remain unchanged and seven lesions (21%) appeared to increase in size. Four pregnancies (10.5%) were complicated by hydrops fetalis which was associated with a poor outcome. Thirty-seven babies were liveborn. Seven babies (18.9%) developed respiratory distress. Two of these babies died within two days of birth resulting in three deaths in total. Two babies were lost to follow up (n=33). Sixty per cent of babies in whom the CCAM appeared to resolve on antenatal ultrasound had an abnormal chest X-ray (CXR). All computed tomography (CT) scans (eight of eight) in this group were abnormal. Of the surviving babies, 27.3% (nine of 33) have had surgery to date.

Conclusions: The antenatal diagnosis of CCAM is associated with a good short-term prognosis. The pregnancy should initially be managed at a tertiary centre with serial ultrasound. Asymptomatic babies should have a postnatal CT even if the CCAM appears to have resolved or decreased on antenatal ultrasound.