Biological Sources for Environmental Birth Defects
I. Rubella Virus-
The virus can cause various deformities depending upon when the mother has been exposed to the infection. Exposure to the virus increases the chances of miscarriage or stillbirth. The virus can cause-
- Vision loss, cataracts, glaucoma
- Deafness
- Heart defects
- Mental retardation
- Cerebral palsy
- Skin rashes
II. Cytomegalovirus (CMV) Infection- It can cause mental retardation and hearing loss.
III. Toxoplasmosis Infection- Mother’s exposure to the single-celled parasite Toxoplasma gondii during pregnancy can cause-
- Eye infections
- Hearing loss
- Learning disabilities
- Enlarged liver or spleen
- Mental retardation
- Cerebral palsy
IV. Venereal Diseases
Herpes simplex virus, syphilis and gonorrhea can cause birth defects.
Genital Herpes- A baby can become infected during birth if the disease is in the active stage. Herpes infection of a newborn usually results in death or brain damage.
Syphilis - Syphilis can be passed from the maternal bloodstream to the fetus between the 14-18th week of pregnancy or during birth from active sores in the birth canal. There may be defects like-
- Heart defects
- Joint deformity
- Blindness
- Deafness
- Mental retardation may appear later in life
Gonorrhea - The baby may contract severe eye infection, which can cause blindness if it is not treated immediately with eye drops.
V. Radiation
Exposure of the fetus to very high levels of x-rays can lead to serious abnormalities like-
- Microcephaly (small head) with associated retardation
- Bone defects in the skull
- Spinal and eye defects
- Cleft palate
- Severe limb deformities
- Increases the chances of developing diseases of the respiratory system, blood disorders and infectious illnesses in childhood.
- Leukemia
