Prenatal Testing
The following prenatal tests are available to pregnant women to detect spina bifida before their babies are born.
- Alpha Fetoprotein (AFP) Test — AFP is the prenatal test that's most commonly used to detect spina bifida. This simple blood test is performed between weeks 15 and 20 of pregnancy. It measures the levels of alpha fetoprotein (AFP), a protein released by the baby's liver and found in the mother's blood, as well as human chorionic gonadotropin (hCG), a hormone produced during pregnancy, and estriol, another hormone produced in significant amounts during pregnancy. Abnormal results of the AFP test may indicate a spinal cord defect, such as spina bifida. It may also indicate fetal brain defects, multiple fetuses, a miscalculated due date or Down syndrome.
Typically, AFP screening is performed by a woman's obstetrician. If test results are high, the test may be repeated to confirm. If test results still indicate a potential risk for spina bifida or other birth defects, patients may be referred to the UCSF Prenatal Diagnosis Center for follow-up testing.
- Ultrasound — This harmless, non-invasive test uses high-frequency sound waves to create images of the fetus. It may detect a spinal cord defect caused by spina bifida or discover other reasons for high levels of AFP.
- Amniocentesis — This test is performed between weeks 15 and 20 of pregnancy. The test may be recommended to women who have high levels of AFP that couldn't be explained by an ultrasound. During the procedure, a small sample of the amniotic fluid surrounding the fetus is taken. Higher than average levels of AFP in the fluid may indicate spina bifida or other birth defects.
Postnatal Testing
If spina bifida is mild, it may not be detected until after a baby is born. Imagining tests such as magnetic resonance imagining (MRI) or computed tomography (CT) scans may be used to detect any abnormalities in the baby's spine or vertebrae.
If hydrocephalus — a condition in which excessive fluid accumulates in the brain — is suspected, doctors may perform a CT scan or ultrasound of the baby's brain.
Reviewed by health care specialists at UCSF Benioff Children's Hospital.
Last updated July 14, 2010
