A birth defect, also known as congenital disorder, is a condition present at birth regardless of cause. They may result in health problems such as physical disability, intellectual disability, or developmental disability. Severity may vary from mild to severe. They are divided into two main types: structural birth defects in which there is problems with the shape of a body part and functional birth defects in which there is problems with how a body part works. Some birth defects include problems of both types.
Birth defects may result from genetic or chromosomal problems, exposure to certain medications or chemicals, or certain infections during pregnancy. Risk factors include not enough folic acid, drinking alcohol or smoking during pregnancy, poorly controlled diabetes, and a mother over the age of 35 years old. Many are believed to involve a number of factors. Birth defects may be visible at birth or diagnosed by screening tests.
Treatment varies depending on the defect in question. This may include therapy, medication, surgery, or assistive technology. Birth defects affected about 96 million people as of 2015. In the United States they occur in about 3% of newborns. They resulted in about 628,000 deaths in 2015 down from 751,000 in 1990. The types with the greatest numbers of deaths are congenital heart disease (303,000), followed by neural tube defects (65,000).
Fetal alcohol exposure
The mother’s consumption of alcohol during pregnancy can cause a continuum of various permanent birth defects : cranofacial abnormalities, brain damage, intellectual disability, heart disease, kidney abnormality, skeletal anomalies, ocular abnormalities.
The prevalence of children affected is estimated at least 1 percent in U.S. as well in Canada.
Very few studies have investigated the links between paternal alcohol use and offspring health.
However, recent animal research has shown a correlation between paternal alcohol exposure and decreased offspring birth weight. Behavioral and cognitive disorders, including difficulties with learning and memory, hyperactivity, and lowered stress tolerance have been linked to paternal alcohol ingestion. The compromised stress management skills of animals whose male parent was exposed to alcohol are similar to the exaggerated responses to stress that children with Fetal Alcohol Syndrome display because of maternal alcohol use. These birth defects and behavioral disorders were found in cases of both long- and short-term paternal alcohol ingestion. In the same animal study, paternal alcohol exposure was correlated with a significant difference in organ size and the increased risk of the offspring displaying ventricular septal defects (VSD) at birth.
Substances whose toxicity can cause congenital disorders are called “teratogens”, and include certain pharmaceutical and recreational drugs in pregnancy as well as many environmental toxins in pregnancy.
A review published in 2010 identified 6 main teratogenic mechanisms associated with medication use: folate antagonism, neural crest cell disruption, endocrine disruption, oxidative stress, vascular disruption and specific receptor- or enzyme-mediated teratogenesis.
It is estimated that 10% of all birth defects are caused by prenatal exposure to a teratogenic agent. These exposures include, but are not limited to, medication or drug exposures, maternal infections and diseases, and environmental and occupational exposures. Paternal smoking use has also been linked to an increased risk of birth defects and childhood cancer for the offspring, where the paternal germline undergoes oxidative damage due to cigarette use. Teratogen-caused birth defects are potentially preventable. Studies have shown that nearly 50% of pregnant women have been exposed to at least one medication during gestation. During pregnancy, a female can also be exposed to teratogens from the contaminated clothing or toxins within the seminal fluid of a partner. An additional study found that of 200 individuals referred for genetic counseling for a teratogenic exposure, 52% were exposed to more than one potential teratogen.
Medications and supplements
Probably, the most well-known teratogenic drug is thalidomide. It was developed near the end of the 1950s by Chemie Grűnenthal as a sleep inducing aid and antiemetic. Because of its ability to prevent nausea it was prescribed for pregnant women in almost 50 countries worldwide between 1956–1962. Until William McBride published the study leading to its withdrawal from the market at 1961, about 8- 10 000 severely malformed children were born. The most typical disorder induced by thalidomide were reductional deformities of the long bones of the extremities. Phocomelia otherwise a rare deformity, which therefore helped to recognise the teratogenic effect of the new drug. Among other malformations caused by thalidomide were those of ears, eyes, brain, kidney, heart, digestive and respiratory tract. 40% of the prenatally affected children died soon after birth. As thalidomide is used today as a treatment for multiple myeloma and leprosy, several births of affected children were described in spite of the strictly required use of contraception among female patients treated by it.
Vitamin A, or retinol, is the sole vitamin which is embryotoxic even in a therapeutic dose, for example in multivitamins, because its metabolite, the retinoic acid, plays an important role as a signal molecule in the development of several tisues and organs. Its natural precursor, the β-carotene, is considered safe, whereas the consumption of animal liver can lead to malformation, as the liver stores lipophile vitamins, including retinol. Isotretinoin (13-cis-retinoic-acid; brand name Roaccutane), vitamine A analog, which is often used to treat severe acne, is such a strong teratogen that just a single dose taken by a pregnant woman (even transdermally) may result in serious birth defects. Because of this effect, most countries have systems in place to ensure that it is not given to pregnant women, and that the patient is aware of how important it is to prevent pregnancy during and at least one month after treatment. Medical guidelines also suggest that pregnant women should limit vitamin A intake to about 700 μg/day, as it has teratogenic potential when consumed in excess. Vitamine A and similar substances can induce spontaneous abortions, premature births, defects of eyes (microphthalmia), ears, thymus, face deformities, neurological (hydrocephalus, microcephalia) and cardiovascular defects, as well as mental retardation.
In this video are ten unusual kids you won’t believe exist. Some of these kids were born with health conditions and disabilities while others discovered a unique talent. Some of these kids also accomplished something incredible for their age, bringing on media attention and exposure to the rest of the world. While these kids are unique and different, the world should remember that they are just kids, and are entitled to a childhood just like the rest of us, even if it is unique.