Likelihood of YOU Having a child with Spina Bifida:
*Spina Bifida is rare, but it's the 2nd most common abnormality in children, after Cerebral Palsy.
*Spina Bifida occurs in 1 out of every 1000 births. 2500 babies are born with SB in the US yearly. Worldwide, more than 400,000 babies develop SB each year.
*The risk is higher if there is a family member affected and it depends on how close that family member is. We share the same genes with family members and this is what increases the risk if there is an inherited component to a condition. 1st degree relatives (parents, children, or siblings) share around 50% of genes and 2nd degree ones (aunts, uncles, nieces, nephews, grandchildren) share about 25%.
*The risk of Spina Bifida in your offspring given that your brother or sister-in-law is affected, is around 2%.(1 in 50) This is a rough estimate based on generalisations, so it would be important to see a genetic counselor for specific advice.
*It is clear that in the general population, the chance of a child having Spina Bifida is about 0.1 – 0.2% worldwide
*The most important time Folic Acid is needed is during very early development, much of which takes place before you know you're pregnant. This is why it is advisable to take it before you start trying-this will also correct any long-term deficiency which might be present.
*If a 1st degree family member has been affected previously, a higher dose (5mg per day) of Folic Acid is advised. The chances are increased if a woman’s close blood relative has had a child with Spina Bifida.
*The highest rate of Spina Bifida is in the United Kingdom
*The lowest rate of Spina Bifida is in Japan.
*In families where 1 child already has Spina Bifida, the chance of a 2nd baby with SB is 2.5 to 5%. If a woman has already had a child with Spina Bifida, the chance of having another affected child is 1 in 20. This doubles for parents who already have 2 children with SB.
* A woman who has Spina Bifida is also at higher risk of having a Spina Bifida child. It seems that only 5% of the cases involve direct hereditary effects, however. So a woman who has Spina Bifida has about a 1 – 5% chance of having a Spina Bifida child and that increases to 15% if both parents have Spina Bifida. This is clearly more complex a condition than one that is directly passed down from the parents.
*If your ancestry is Irish, German, or Hispanic, your risk of having a baby with Spina Bifida is higher than the general population, and it's lower if you have Asian or Pacific Islander ancestry. Because of these differences and it's tendency to run in families, genetics probably plays a role in Spina Bifida, although no specific gene has been identified.
*More recently, specific genes that seem to be linked to this neural tube defect have been discovered. Since Spina Bifida is a heterogeneous disease, it is likely that several genes will be involved or that an entire metabolic pathway is affected in various ways. A study looking at the DNA of 1500 children with the condition and their parents found that a group of genes involved in glucose metabolism seem to have some sort of link to those who are born with Spina Bifida. In addition, the gene mthfr also seems to be involved in at least some of the Spina Bifida cases.
*95% of babies born with Spina Bifida have no family history of it.
*There is no way to prevent a baby from having a birth defect. It's only possible to reduce the risk. Studies show that the risk is reduced up to 70% when women take folic acid at least 1 month before and through the 1st three months of pregnancy.
*Women who have no personal or family history of SB should take 400 mcg of folic acid every day.
*Women who have had a pregnancy with Spina Bifida should take 4000 mcg (4 mg) every day but require a prescription to get that dose the proper way. Do not raise the dose by taking more of a multivitamin because the high levels of the other vitamins are harmful.
*To increase folic acid, women should also add to their diet folate-fortified cereals and breads and other naturally folate-rich foods such as dark green vegetables, eggs and certain fruits.
*Many things affect pregnancy including genes, environment, and certain illnesses or drugs. These include:
-Prior pregnancy with Spina Bifida (the chance of the next pregnancy being affected is 20-50 times greater)
-Family history of SB
-Mother with insulin dependent diabetes (particularly when blood sugar levels are elevated in early pregnancy. Good blood sugar control and diabetes management may decrease the risk)
-Mother with medically diagnosed obesity. (Women who are obese before becoming pregnant are at a higher risk for having a baby with SB than women of average weight. The link between pre-pregnancy obesity and neural tube defects is unclear, but 1 theory is that poor eating habits and inadequate nutrition may contribute. Another theory is that obese women frequently have diabetes, a known risk factor for Spina Bifida and other neural tube defects.)
-Race and ethnicity. (SB is more common in Caucasians than African-Americans and more common in Hispanics than non-Hispanics.)
-Mother's use of some prescription drugs which may include anti-seizure medications and fertility drugs, among others. This info should be discussed with the prescribing physician and the OB GYN before becoming pregnant.
-A history of seizure disorders in the mother and the use of anticonvulsants.(Medications such as Valproic Acid and Carbamazepine may set the stage for NTDs because they block the body's ability to process folic acid.) These medications are also used to treat some mental health conditions, such as Bipolar Disorder.
*Very rarely, Spina Bifida can occur alongside a genetic condition such as Patau's Syndrome, Edward's Syndrome, or Down's Syndrome.
*Other things raise the chance of having a baby with Spina Bifida, but they are not as well understood. These things include:
-Exposure to high temperatures in early pregnancy, such as prolonged high fevers
-Extended hot tub or sauna use
(elevated core body temperature by even 3 or 4 degrees very early in pregnancy has been linked with increased risk of Spina Bifida.)
-Parental exposure to Agent Orange.
-Inadequate folic acid intake in the mother's diet. Folic Acid (Vitamin B-9) in the mother's diet is key to the development of a healthy fetus. Lack of folic acid increases the risk of Spina Bifida and other neural tube defects.
-Lower socioeconomic status. (again, poor nutrition may be the key issue here.)
This info was compiled with help from the following websites:
http\://www.spinabifida.net/causes/hereditary-and-genetics.html
http\://livehealthy.chron.com/chances-baby-having-spina-bifida-1094.html
http\://www.marchofdimes.org/complications/spina-bifida.aspx
http\://www.spinabifidaassociation.org
http\://www.mychildwithoutlimits.org
http\://www.americanpregnancy.org
http\://www.nhs.uk
