Table Surveillance Protocol for Trisomy 18 Time Period Surveillance Recommendations Prenatal Ultrasonography at 19 weeks gestation Fetal echocardiography considered if known trisomy 18 diagnosis or abnormal ultrasound Postnatal Physical examination for external anomalies Complete blood count with differential Echocardiography Total abdominal ultrasonography, including urinary system (48 - 72 hours after birth) *, † Cranial ultrasonography and / or MRI Early screening by pediatric ophthalmologist Airway assessment, possibly including sleep study Baseline serum AFP level 0 - 12 months of age Total abdominal ultrasonography at 3, 6, 9, and 12 months of age Serum AFP levels at 3, 6, 9, and 12 months of age Frequent feeding assessments Audiology examination at 6 - 8 months of age Dental screening 1 - 4 years of age Annual ophthalmologic evaluation After 2 years of age, annual orthopedic examination and spinal x-rays Serum AFP levels every 3 - 4 months Abdominal ultrasonography every 3 months until 4 years of age Dental evaluation every 6 months 4 - 7 years of age Annual ophthalmologic evaluation Annual orthopedic examination and spinal x-rays Abdominal ultrasonography every 6 months Renal ultrasonography every 3 months until 7 years of age Dental evaluation every 6 months 7 - 12 years of age Annual ophthalmologic evaluation Annual orthopedic examination Abdominal ultrasonography every 6 months until 12 years of age Puberty Clinical evaluation for seizures, behavioral changes, and normal sexual development, including menses in females‡ ≥ 12 years of age Annual ophthalmologic evaluation Annual orthopedic examination * If prenatal ultrasound showed or suggested hydronephrosis but postnatal ultrasound was normal, renal ultrasonography is done at 4 to 6 weeks of age.