Birth Defects & Genetics
Expecting mothers probably alternate between the fantasies of having a healthy baby or having a baby with some health problem. Or may be through some prenatal screening, they have come to know that the child may be born with some birth defects. It’s a common assumption that all birth defects are serious and fatal but the fact is most of the birth defects are treatable, often immediately after birth or sometimes even before the baby is born.
If you are thinking of becoming a mother, it is as important to be aware of the possibility of having a birth defect in your child as it is know about the diet and exercises to be followed during the pregnancy period. Though discussing about birth defects can be very upsetting, having a proper knowledge about them can prevent your child from developing one.
Birth Defects- An Introduction:
Birth defects are defined as abnormalities in the structure of an organ or the function in the baby’s body since birth. Birth defects also known as congenital disorders or anomaly, involve defects in or damage to the developing fetus. These disorders lead to physical or mental disabilities or are fatal.
There are 4000 known different birth disorders, ranging from minor to major. Although most can be cured, they are leading cause of babies’ death in the first year of their life.
Causesof birth defects:
Birth defects can result due to genetic, environmental or other unknown factors. Most babies with birth defects are born to parents with no obvious health problems or risk factors.
• Genetics plays an important role in the development of some birth defects. Genetic birth defects are usually hereditary in nature and are passed down to a child by its parents.
Every human body is made of millions of cells. Each cell has 23 pairs of chromosomes which contain gene. These act as the hereditary materials and transfer the traits or the characteristics from parents to the offsprings. Out of the 46 chromosomes that a child has, 23 chromosomes are inherited from the mother and 23 from the father. So in the process if any one of the parents or both have the faulty gene, it gets transferred to the child. It is assumed that 20% of all birth defects are hereditary in nature.
There are number of ways hereditary birth defects can pass on to your child. Some defects can pass on by the mother, some by the father while some can be inherited by both the parents. There are three main ways of birth defect inheritance:
Dominant Inheritance: Only one of the parents has the genetic defect which passes on to the child. Example: Marfan Syndrome (abnormal long fingers, arms and legs), Achondroplasia (a form of dwarfism).
Recessive Inheritance: Both the parents have the faulty gene which passes on to the child. Example: Tays-Sachs disease (affects the central nervous system), Cystic fibrosis.
X-linked Inheritance: Here, the genetic defect is present only on the X-chromosome. And these X-linked birth defects are passed on from the mother to son. Example: Color blindness, Hemophilia.
An alteration in the number or structure of the chromosomes can also lead to the occurrence of the birth defects. An error during the formation of egg or sperm or during fertilization can result in the child to be born with decreased or increased number of chromosomes or with the damaged chromosomes. The risk of this type of birth defect normally increases with the age of the mother. Birth defects like Down’s syndrome and Turner’s syndrome are due to this reason.
• Environmental Causes: Birth defects due to environmental causes comprise of the mothers health and the exposure to certain radiations, chemicals or diseases infections. If a mother is infected by certain disease like rubella infections during pregnancy, then the baby is likely to be suffering from a birth defect. Alcohol consumption by mother during pregnancy or intake of certain medications can cause birth defects like Fetal Alcohol Syndrome.
• Multifactorial birth defects are caused by the combination of various genetic and environmental factors. These include neural tube defects, cleft lip or palate.
Diagnosis of birth defects:
Couples expecting the arrival of their baby are surrounded with fears of having a baby with the birth defect since most of the defects cannot be detected until the baby is born. Luckily, modern technology provide solutions and diagnostic measures that reveal some defects , if any, and help safeguard the health and future of the baby.
Diagnostic methods like ultrasonography, Chorionic Villus Sampling (CVS) and amniocentesis help to find out the birth defects like:
• Neural tube defects
• Congenital heart defects
• Congenital tumors
• Metabolic disorders
• Limb defects
• Gastrointestinal and kidney malfunctions
• Cleft lip or palate
• Chromosomal abnormalities like Down’s Syndrome.
Ultrasonography:
Also known as ultrasound techniques, it is common and simple methods of detecting the birth defects. It determines specifically the possibility of the structural birth defects in the heart or the urinary tract and spina bifida. It is usually used after three months of pregnancy and does not harm the fetus. Apart from the birth defect detection, it also reveals information regarding the normal growth of the fetus and its position in the womb.
Chorionic Villus Sampling (CVS):
Chorionic villi are tiny projections in the inner lining of the placenta. A sample of these tiny projections is taken to determine any birth defects in the fetus.
One of the greatest advantages of this test is that it can be done in the very early stage of pregnancy, during the 10th or the 11th week, thus providing the better possibility for the diagnosis and the treatment. Here if the baby is found to have the birth defect than the parents have the option to terminate their pregnancy as per their wish.
CVS is more accurate than the ultrasound alone. Generally, the doctor first determines the position of the fetus in the womb and then removes the sample through the cervix to detect the birth defect.
Amniocentesis:
This has become a common method for detecting any birth defects. This test is performed usually after 14 weeks of pregnancy.
Here a sample of the amniotic fluid is taken by a syringe inserted through the abdomen. This amniotic fluid is used to diagnose the disorders. Prior to this ultrasonography is done to determine the fetal position in the womb.
Amniocentesis mainly checks the alpha-fetoprotein level in the amniotic fluid, which indicates whether the fetus is having any brain or spinal cord defect.
Apart from these, there are diagnostic techniques as well to determine the birth defects. Tandem mass spectroscopy screens for metabolic disorders in on a small blood sample. Another diagnostic method known as PUBS (Percutaneous Umbilical Blood Sampling), is used for the chromosomal analysis during the later stage of the pregnancy if a defect has been indicated in the ultrasound diagnosis.
Prevention of birth defects:
The following steps can be taken before or during the pregnancy to ensure that your baby is free of any birth defects.
Before Pregnancy:
• All expectant mothers should ensure that their vaccination is up to date.
• Ensure that the expectant father and the mother do not have any sexually transmitted diseases.
• Folic acid is an important Vitamin which is needed to generate new blood cells. Regular intake of folic acids provides neural tube defects. Expecting mothers should start taking the folic acid supplement at least a minimum of six months before they try to start getting pregnant.
• Expecting mothers should check with their doctor before taking any over the counter or prescription medications.
• In case of a family having a history of genetic diseases, it is advisable to have a genetic counseling before you plan for any child. A genetic counselor helps you to understand the root cause the problem, discuss various prenatal tests available and help you to resolve your problems and doubt.
• Discuss with your doctor and make sure that none of your health conditions, including diabetes, harm the baby in any way. Keep all your health conditions under control.
During Pregnancy:
• Avoid smoke, alcohol or any drug.
• Avoid yourself from the vicinity of any harmful chemical toxins.
• Drink plenty of fluids.
• Eat a healthy and balanced diet.
• Take your daily dose of folic acid and iron, as per your doctor advises.
• Get the genetic testing done to ensure that your baby free of any birth defects.
• Exercise moderately.
• And get plenty of rest.
Treatment of the defects before birth:
Some birth defects, if detected early can be cured in time before birth. In time detection before birth, helps to successfully repair the urinary tract defects, congenital diaphragm disorders and abnormalities of the lungs. Spina bifida which is a major birth defect can also be cured and chances of survival of the fetus increases by performing surgery on the fetus. Administering certain medications to mothers can provide help for differences in the Rh factors and for abnormal heart rhythms.
Copying with birth defects:
Having a child with a birth defect is very unfortunate. It can be difficult for the parents especially the mother, both physically as well as emotionally. However reacting negatively may worsen the situation both for the mother as well as the baby. Few of the ways you can follow to cope with such a situation is:
• Speak openly about your emotions. Don’t hesitate and keep your grief in your heart. Share them with your partner and family members and if required consult a psychologist.
• Treat your child differently. Be good to him/her and celebrate his/her small achievements and be proud of him/her.
• Try to get to know some other parents whose child has any birth defects. You will get the support and courage from such parents.
• Try to get more information about your child’s defect. Try to learn the exact nature of the defect and what you can do to make him/her feel better.
• It is best to start the treatment as early as possible. It is very important to improve the quality of the life for your child.
