Prevalence:

• 1 in 5,000 births.

Ultrasound diagnosis:

• ‘Double bubble’ sign as a result of an enlarged stomach and duodenal cap. Usually found >24 weeks’ gestation.
• Polyhydramnios >24 weeks’ gestation in 50% of cases.

Associated abnormalities:

• Chromosomal defects, mainly trisomy 21, are found in 30% of cases.
• Other defects, mainly cardiac, renal, vertebral, are found in 10-20% of cases.

Investigations:

• Detailed ultrasound examination, including echocardiography.

Follow up:

• Ultrasound scans every 2-3 weeks to monitor growth and assess amniotic fluid volume. Amniodrainage may be necessary if there is polyhydramnios and cervical shortening.

Delivery:

• Place: hospital with neonatal intensive care and pediatric surgery.
• Time: 38 weeks.
• Method: induction of labor aiming for vaginal delivery.

Prognosis:

• Survival rate >95%.

Recurrence:

• Isolated: no increased risk of recurrence.
• Part of trisomy 21: 1%.