There are more than 4,000 different kinds of birth defects that can range from minor ones that can last one’s whole life without any major treatment to life-threatening conditions or disabilities that need urgent medical attention.
Congenital disorders can be broadly categorized under four heads:
- Chromosomal abnormalities: 46 chromosomes are supposed to be there in any healthy child (23 from each parent). But when 46 chromosomes are missing or get duplicated, it causes infants to develop physically and mentally at a different rate of growth.
For example; Down syndrome
- Single-gene abnormalities: Occurs when the chromosome are normal in number, but there maybe one or more genes than the normal number.
Some common disorders under this head are:
- Autosomal dominant inheritance – a genetic abnormality passed on to the child if one of the parents has the same abnormality.
- Autosomal recessive inheritance – a genetic abnormality that can be passed on to the child only if both parents carry the same defective gene.
In these cases, both parents are normal, but 1 in 4 of their children would be expected to be affected.
For example diseases like Cystic fibrosis, Tay-Sachs disease, sickle cell anaemia.
- X-linked conditions – genetic abnormalities that mainly occur in males. Females may carry the abnormal gene that can cause X-linked recessive disorders, but may not show the actual disease.
For example haemophilia, colour blindness, forms of muscular dystrophy
- X-linked dominant conditions – occurs in both males and females; however, they are more severe in males. Includes certain neurological conditions affecting the brain, skin disorders and types of skeletal or craniofacial disorders.
- Conditions during pregnancy that can affect the baby – Deals with all disorders and diseases that could have been implicated on the growing foetus due to conditions experienced by the mother during gestation.
- Certain illnesses during pregnancy, particularly during the first nine weeks, can cause serious congenital abnormalities.
For example, maternal infections such as cytomegalovirus, chickenpox or rubella are common diseases that can be contracted by the foetus during pregnancy.
- Chronic maternal conditions like diabetes, hypertension, and autoimmune diseases such as lupus, myasthenia gravis or graves’ disease, can negatively affect the developing foetus.
For example, maternal hypertension can affect blood flow to the foetus, impairing foetal growth.
- Alcohol consumption and certain drugs during pregnancy increase the risk of a baby being born with abnormalities like foetal alcohol spectrum disorders.
- Eating raw or uncooked foods during pregnancy can also be dangerous to the health of the mother and foetus and should be avoided.
- The combination of Genetic and Environmental Problems – Congenital abnormalities occur if there is a genetic abnormality which can be triggered off or further aggravated when combined with exposure to certain environmental influences within the womb during critical stages of the pregnancy.
For example, Spina bifida and cleft lip and palate.
Apart from these few major categories, there are a number of congenital disorders that occur without any known or fixed cause. Treatment varies case to case and depending on the severity of each issue.
In all cases, however, one should not wait for symptoms to fully develop and he child to grow old. They should contact a child specialist right after delivery so that the disorder can be monitored, and a surgery can be carried out at the most opportune time.