Clinical Edge

Summaries of Must-Read Clinical Literature, Guidelines, and FDA Actions

Prevention of Neural Tube Defects

Obstet Gynecol; ePub 2017 Dec; ACOG, et al

The American College of Obstetricians and Gynecologists (ACOG) has issued management recommendations about neural tube defects (NTDs) for pregnancies completed by a fetal NTD, with primary prevention of NTDs possible with folic acid. Among the recommendations:

Level A:

  • All women planning a pregnancy or capable of becoming pregnant should take 400 micrograms of folic acid supplementation daily. Supplementation should begin at least 1 month before pregnancy and continue through the first 12 weeks of pregnancy.
  • Women at high risk of NTDs should take 4 mg (4,000 micrograms) of folic acid daily. The daily supplement should be initiated 3 months before pregnancy and continued until 12 weeks of gestational age.

Level B:

  • Ultrasonography in the second trimester is recommended for all pregnant women; the optimal time for a single ultrasound examination is 18–22 weeks, allowing for confirmation of gestational age and screening for anomalies, including NTDs.
  • Although it is possible to detect some NTDs in the first trimester, the detection rate appears to be much lower than with second-trimester ultrasonography. Therefore, a normal first-trimester ultrasound examination should not be substituted for a screening ultrasonography at 18–22 weeks.
  • A patient with a fetus with an NTD should be offered the management options of pregnancy termination, expectant management with neonatal surgical repair, and in utero fetal repair for appropriate candidates.
  • For the patient who elects to continue the pregnancy, genetic evaluation by amniocentesis for chromosomal microarray should be recommended.


Neural tube defects. Practice Bulletin No. 187. American College of Obstetricians and Gynecologists. Obstet Gynecol. 2017;130:e279–90.