Prevention of Birth DefectsheadingContent
January is National Birth Defects Prevention Awareness Month. Did you know that five percent of babies are born with a birth defect of some kind? Most of these defects are very small and insignificant; for example, a birth mark or skin lesion. However, some defects are more serious.
Defects can fall into a number of categories:
- Genetic defects
- Mechanical defects
- Defects due to toxins
- Unknown defects
Genetic defects – these are due to mutations of one or more genes. Some mutations are inherited but most are not. There are many types of genetic defects; In fact, there are book volumes devoted to genetic abnormalities and the risk of genetic mutations rises with age. Mothers above the age of 35 are at a mildly increased risk. Moms above the age of 40 are at much higher risk.
These defects cannot be prevented except for those who undergo IVF (in vitro fertilization); pre-implantation identification of defects can prevent those pregnancies from occurring. Nowadays, genetic abnormalities can be identified way before birth, traditionally via amniocentesis – a sample of amniotic fluid is removed and analyzed, after 15 weeks. Now, at as early as nine weeks, fetal cells can be extracted through the mother’s blood (a simple blood draw is evaluated). This is a much safer test but may have a slightly decreased accuracy. Nevertheless, this type of non-invasive genetic evaluation is revolutionizing obstetrics.
Can genetic makeup be changed, once diagnosed? The answer is no.
For the most part, parents use the information to prepare, to arrange proper evaluation and treatment right at the time of birth. But researchers are looking into having the ability to change genetics. For example, Cystic Fibrosis is a serious genetic disease which affects the lungs. Researchers are working on a way of inserting non-faulty genetic material directly into the lung, which would improve function.
Mechanical defects – these defects are usually due to outside forces. Amniotic Band Syndrome falls into this category; a band of tissue forms around a part of the developing baby, and causes an abnormality, usually in a limb.
Defects due to toxins – toxins may be environmental, radioactive or chemical. For example, environmental toxins would include exposure to pesticides. Radiation exposure (from X-rays) is usually benign in nature because it takes a large amount of radiation to cause defects. Chemical exposure includes illegal and legal drugs.
Most medications are considered safe in pregnancy but there are a number of medications which are toxic. A good example is Accutane, a form of vitamin A, which can cause serious birth defects. When evaluating whether or not to take a medication in pregnancy, the patient and doctor need to look at the possible risks versus the benefits. For many medications, the possible risks are small and the benefits are large, such as asthma medications – which are important because without treatment, asthma attacks may lead to lower oxygen levels, which are dangerous for the developing baby. There are numerous instances when pregnant moms must take medication. Sometimes, not taking medications could lead to fetal harm, like with asthma. A common mistake is for a mother to stop her medication, such as high blood pressure or epilepsy, and then become ill. Always ask your doctor before stopping medications.
Unknown defects include abnormalities of almost any kind which have no known cause, like birth marks, cardiac defects, spina bifida – exposed spinal cord – brain abnormalities and many others. These defects cannot be prevented nor predicted. Some of these defects can be diagnosed before birth via ultrasound but many cannot.
Can defects be prevented? Some can.
It is known that folic acid supplementation prior to conception decreases to risk of spina bifida. Diabetes can be associated with heart and other abnormalities; good sugar control, prior to conception, decreases these risks significantly. The avoidance of toxin exposure and known teratogenic medications prior to conception is important as well. A pre-conception consult with your OBGYN is recommended to discuss.
The good news? Defects are uncommon and when defects do occur, they are usually minor.