What causes birth defects

Overview of Birth Defects

 

Birth defects, also called congenital anomalies, are physical abnormalities that occur before a baby is born. They are usually obvious within the first year of life.

The cause of many birth defects is unknown, but infections, genetics, and certain environmental factors increase the risk.

Before the baby is born, the diagnosis may be based on the mother's risk factors, the results of an ultrasound, and sometimes blood tests, amniocentesis, or chorionic villus sampling.

After the baby is born, the diagnosis may be based on a physical examination, imaging tests, and blood tests.

Some birth defects can be prevented by maintaining good nutrition while pregnant and avoiding alcohol, radiation, and certain drugs.

Some birth defects can be corrected with surgery or managed with drugs.

Birth defects can involve any part of any organ in the body, including the following:

 

• Bones, joints, and muscles

• Brain and spinal cord

• Digestive tract

• Heart

• Urinary tract and genitals

• Some birth defects are more common than others.

 

Birth defects are the leading cause of death in infants in the United States, and some cause the death of the fetus, causing miscarriage or stillbirth.

 

A birth defect is evident in about 7.5% of all children by age 5 years, although many of these are minor. Major birth defects are evident in about 3 to 4% of newborns.

 

Several birth defects can occur together in the same infant.

Causes of and Risk Factors for Birth Defects

It is not surprising that birth defects are fairly common, considering the complexities involved in the development of a single fertilized egg into the millions of specialized cells that constitute a human being. Although the cause of most birth defects is unknown, certain genetic and environmental factors increase the chance of birth defects developing. These factors include exposure to radiation, certain drugs

 

Some risks are avoidable. Others occur no matter how strictly a pregnant woman adheres to healthful living practices. Many birth defects develop before a woman knows she is pregnant.

 

Exposure to harmful substances (teratogens)

A teratogen is any substance that can cause or increase the chance of a birth defect. Teratogens include

 

Radiation (including x-rays)

Certain drugs

Toxins (including alcohol)

Most pregnant women who are exposed to teratogens have newborns without abnormalities. Whether a birth defect occurs depends on when, how much, and how long the pregnant woman was exposed to the teratogen (see Exposures During Pregnancy).

 

Exposure to a teratogen most commonly affects the fetal organ that is developing most rapidly at the time of exposure. For example, exposure to a teratogen during the time that certain parts of the brain are developing is more likely to cause a defect in those areas than exposure before or after this critical period.

 

Nutrition

Keeping a fetus healthy requires maintaining a nutritious diet. For example, insufficient folic acid ( folate) in the diet increases the chance that a fetus will develop spina bifida or other abnormalities of the brain or spinal cord known as neural tube defects. Cleft lip (a separation of the upper lip) or cleft palate (a split in the roof of the mouth) is also more likely to develop.

 

Obesity in the mother also increases the risk of a neural tube defect.

 

Genetic and chromosomal factors

Chromosomes and genes may be abnormal. These abnormalities may be inherited from the parents, who may either be affected by the abnormalities or who may be carriers of the genes that cause the abnormalities (see Overview of Chromosome and Gene Disorders). Carriers are people who have an abnormal gene for a disorder but who do not have any symptoms of the disorder.

 

However, many birth defects are caused by new chromosome abnormalities or gene mutations that arise in the fertilized egg and were not inherited from the parents.

 

Birth defects caused by genetic factors often include more than just an obvious malformation of a single body part.

 

Infections

Certain infections in pregnant women can cause birth defects  Whether an infection causes a birth defect depends on the age of the fetus at the time of the exposure to the infection.

 

The infections that most often cause birth defects are

 

• Chickenpox (varicella)
• Cytomegalovirus
• Erythema infectiosum (parvovirus B19 infection, fifth disease)
• Herpesvirus
• Rubella (German measles)
• Syphilis
• Toxoplasmosis (which can be transmitted in cat litter)

A woman can have one of these infections and not know it because some of these infections can cause few or no symptoms in adults.

 

Diagnosis of Birth Defects

Before birth, ultrasonography and sometimes magnetic resonance imaging, blood tests, amniocentesis, or chorionic villus sampling

After birth, physical examination, ultrasonography, computed tomography, magnetic resonance imaging, and blood tests

Before birth

Before birth, doctors assess whether a woman is at increased risk of having a baby with a birth defect ( Prenatal Diagnostic Testing). The chance is higher for women who have the following risk factors:

 

Older age

Have had frequent miscarriages or stillbirths

Have had other children with chromosome abnormalities or birth defects or who died in infancy for unknown reasons

These women may need monitoring and special tests to find out whether their baby is developing normally.

 

Increasingly, birth defects are being diagnosed before the baby is born.

 

Ultrasonography of the fetus is commonly done during pregnancy. Magnetic resonance imaging (MRI) of the fetus may also be done when indicated. These imaging tests can often detect specific birth defects.

 

Sometimes blood tests can also help. For example, a high level of alpha-fetoprotein in the mother's blood may indicate a defect of the brain or spinal cord or certain other organs (see Second-Trimester Screening). More recently, doctors are using a test called cell-free fetal DNA analysis. In this test, a sample of a pregnant woman's blood is analyzed to determine whether her fetus has certain genetic disorders. This test is based on the fact that the mother's blood contains a very small amount of DNA (genetic material) from the fetus. This test is called noninvasive prenatal screening (NIPS). NIPS can be used to detect an increased risk of trisomy 21 (Down syndrome), trisomy 13, or trisomy 18 and certain other chromosome abnormalities. Doctors usually do further testing when an increased risk of a gene abnormality is detected.

 

Amniocentesis (removing fluid from around the fetus) or chorionic villus sampling (removing tissue from the sac around the developing fetus) may help confirm a suspected diagnosis. Genetic testing is done on the samples taken during these procedures.

 

After birth

After birth, the doctor does a physical examination of the newborn. During this examination, the doctor examines the newborn's skin, head and neck, heart and lungs, and abdomen and genitals and assesses the newborn's nervous system and reflexes. Some newborns have a physical appearance that suggests a certain disorder.

 

In the United States, most newborns undergo routine screening blood tests to detect a number of metabolic disorders and genetic disorders.

 

Imaging tests, such as ultrasonography, computed tomography (CT), and magnetic resonance imaging (MRI), may be done based on the results of the physical examination and screening tests.

 

Treatment of Birth Defects

Sometimes surgery or drugs

Abnormal chromosomes or genes cannot be corrected.

 

Surgery can correct or help some birth defects. Drugs and surgery can be used to manage the symptoms caused by other defect

1. CORONA VIRUS
2. MONKEY POX
3. VAGINAL DRYNESS
4. FIBROID
5. INFERTILITY
6. OVULATION CYCLE
7. OVARIAN CANCER
8. VAGINAL BACTERIA
9. MALE INFERTILITY
10. BEST DAYS OF CONCIEVING
11. MUCUS AFTER OVULATION
12. FOODS FOR ERECTILE FUNCTIONS
13. PREGNANCY ANEMIA
14. DO AND DONT DURING PREGNANCY
15. ERECTILE DYSFUNCTION
16. U.T.I IN PREGNANCY
17. STROKE RISK
18. EAT THIS NOT THAT
19. HOOKWORMS INFECTION
20. OMEGA 3 BENEFITS
21. FASTING
22. WEIGHT LOSS TIPS
23. vitiligo
24. ABORTION
25. DENGUE VIRUS
26. EBORA VIRUS
27. FEVER
28. URINARY TRACT INFECTION
29. HOSPITAL INFECTIONS
30. WEST NILE VIRUS
31. YELLOW FEVER
32. EYE DISEASE
33. ZIKA VIRUS
34. STRESS
35. IRON DEFFICIENCE
36. INSOMNIA (SLEEPING PROBLEMS)
37. HEART PROBLEMS
38. COMPONENTS OF BLOOD
39. BLOOD DISORDER
40. LABORATORY TEST OF BLOOD DISORDER
41. BONE MARROW EXAMINATION
42. BLOOD ANEMIA
43. ANIMAL BITES
44. EYE BURN
45. CHOCKING
46. HEAT STROKE
47. SMOKE EFFECTS
48. SNAKE BITE
49. MALARIA VACCINE
50. BEST WAY TO SLEEP A CHILD
51. CHILD FEVER REDUCING
52. ELEPHANTIASIS
53. WOMEN BEARDS
54. DATES
55. PAPAYA FRUITS