|SPINA BIFIDA AND FOLIC ACID|
Ask the doctors: What every woman should know about spina bifida and folic acid.
Responses submitted by: Richard P. Leavitt, Director of Science Information at the National March of Dimes Foundation; Dr. Godfrey Oakley, a visiting professor of epidemiology at the Rollins School of Public Health at Emory University; and Dr. Victor Klein of the North Shore University Hospital in New York.
Laila of Novato, CA asks:
I am a healthy 26-year-old woman. When my husband and I decided to start a family, I went to my doctor to ask what I can do to plan a healthy pregnancy. I got an MMR booster and started taking prenatal vitamins (and I double checked for folic acid). Three months later, I got pregnant.
At 16 weeks I took the AFP test which came back elevated and then I had a level 2 Sonogram which showed anencephaly. It is so frustrating to see reports like this one that say over and over again that "taking a vitamin could prevent these horrible birth defects." I did, and it didn't. Now my doctor has me taking the 4mg dose of folic acid and I am again trying to get pregnant.
Please tell me, is there anything ELSE I can do to try to have a healthy baby? And, if the 4mg dose is so effective, why isn't everyone taking it? My doctor also said we might be able to know if there is a NTD by 12 weeks instead of after the AFP...how does that process work? Is there any way of knowing sooner?
Dr. Godfrey Oakley responds:
Folic acid does not prevent spina bifida and anencephaly in all pregnancies. I wished we had the scientific evidence to know how to prevent all cases. It was just in 1991 that we obtained proof that folic acid would in most situations prevent the majority, but not all, spina bifida and anencephaly pregnancies.
It seems to me that it is very important to try to get the message
to all women of reproductive age, even though we know it will not prevent
all cases. The Congress and foundations need to provide more research
money so that we can find the causes of birth defects that may not be
related to folic acid. Until we know more, I think that you should work
closely with your health care providers. He/she is recommending 4 mg
because that is the amount recommended for women who have previously
had an affected pregnancy.
Richard Leavitt responds:
If you took 400 mcg of folic acid daily before conception and throughout early weeks of pregnancy, the risk of being in your situation was originally quite low, but not zero. Folic acid greatly reduces NTD risk, but does not eliminate it -- and the vitamin appears less effective against anencephaly than against the more common NTD, spina bifida.
Taking 4 mg daily is right for you now. But even for women who have had pregnancies affected by NTDs, that high dose is not recommended between pregnancies until another pregnancy is actually intended. It carries certain theoretical risks that may outweigh its possible advantage for women not known to be at special risk for NTDs in offspring. Folic acid as a broadly based public health program is only a decade old, and ongoing experience may show that current recommendations will need adjustment.
In a future pregnancy, anencephaly may be detected in the 11th or 12th week by ultrasound examination. The more common NTD spina bifida is not usually visible that early.
To learn more about what you can do for the best chance of a having a healthy baby, call 1-888-MODIMES or see March of Dimes online at www.marchofdimes.com
Response taken from the "Plan Ahead Do What You Can" brochure (collaboration between the MOD and the Spina Bifida Association of America) and the book the ABC's of Prenatal Diagnosis.
Dr. Victor Klein responds:
While taking prenatal vitamins such as you did in your pregnancy, it is still possible to have birth defects including neural tube defects. The March of Dimes recommends that all women in the reproductive age group who can get pregnant take 0.4 mg of folic acid usually in the form of a multi vitamin. If a patient is at high risk such as yourself it is recommended to take 4.0 mg of folic acid per day. Four milligrams is a higher dose than thought to be necessary and there are some rare concerns with patients taking too much. Folic acid is a B vitamin which is water soluble and does not get stored in the body.
The standard of care is to do a level II sonogram at 18 weeks to look at the baby's entire spinal cord. However, the severe case of anencephaly can be determined as early as 12 weeks. The AFP blood test done on the mother is performed after 14 weeks and can pick up over 90 percent of open neural tube defects.
Please call me if you have any questions at 466-0778 or e-mail me. Please have some disclaimer that all specific medical questions need to be directed to a person's physician after a detailed history and physical are obtained to take legal precautions.
There are three Web sites that people can access to help them understand spina bifida. The first one is The March of Dimes at: www:modimes.org and the Association for spina bifida and hydrocephalus at: www:asbah.org and the Spina Bifida Association of America www:sbaa.org