Sahana is pursuing PhD in the field of medical informatics & medical decision support system. She writes on the subject of women's health.
Malformations that occur at conception are mainly due to chromosomal factors and cannot be avoided. But malformations that occur during pregnancy are mainly due to maternal factors like drugs, illness, medication etc. during the early stages of pregnancy while the major organs are still forming. Some malformations can be treated successfully while others do not have any known treatments yet. Life threatening defects should be recognized soon after birth and treated accordingly. Good news is most of the congenital defects are possible to detect before birth.
10 common congenital defects along with the causes and the treatment options available are discussed here.
1. Imperforate Anus
Imperforate anus or anorectal malformations (ARM) is a birth defect in which the anus is sealed by a thin membrane of skin or the anal canal that links the rectum with the anus has not developed. The rectal pouch may be connected to vagina, bladder or urethra. It may be diagnosed by physical exam or ultrasound imaging.
- Anal opening very near the vagina.
- No passing of stool within 24 hours of birth.
- Stool passed through vagina, base of penis, scrotum or urethra.
- Missing or moved opening of the anus.
- Swollen abdomen.
Surgery is essential to correct this problem. In case the rectum connects with other organs, these organs need to be repaired. These children need to follow a bowel program which includes eating high fiber foods, taking stool softeners, enema etc.
2. Congenital Heart Disease
Congenital heart disease is a structural problem in the heart that occurs while the fetus still developing. Ventricular sepia defect or hole in the heart is the most common type of congenital heart disease.In this condition there is a hole in the baby's septum i.e. the thin dividing wall between the right and left ventricle.of the heart. Thus the ventricles or pumping chambers are connected instead of being divided,
Heart of a fetus start to develop about 22 days after the conception. Between 22nd and 24th day the heart begins to bend to the right and fold itself into a loop. By the 28th day, the tube has a general heart-shaped form with the structures of the chambers and blood vessels in place. It is during this stage of development the structural defects arise.
Due to this problem the blood flow in the heart may slow down or go in the wrong direction or it may also block the flow completely.
Cause of congenital heart disease can be varied ranging from genetic factors to maternal disease or medications. Women who contact rubella (chicken pox) during the first trimester of pregnancy have an increased risk of having a baby with congenital heart defects.
Anticoagulants and anti-depressant medications also raise the risk. According to the U.S. National Library of Medicine and the National Institute of Health, a new study indicates that women who smoke during early pregnancy are more likely to have a child with congenital heart defects. The study indicates that women who smoked at some point in the month before conception through the end of the first trimester were 60% more likely to have babies with congenital heart defects.
Maternal disease like diabetes and deficiency in B vitamin folic acid may be another contributing factor.
Malformations are more likely to occur in siblings or offspring of people with congenital heart disease than those without it.
Nowadays some congenital heart problems can be detected during the ultrasound in the second trimester of pregnancy. If confirmed fetal echo cardiogram is performed. It is a detailed ultrasound of the fetal heart.
A small camera called a transducer is placed on the mother's abdomen. The ultrasound waves that it sends out bounce off the baby's organs, including the heart and are sent back to the camera which then creates a moving picture of the different parts of the heart for the doctor to evaluate. The sound waves can also detect blood flow throughout the baby's heart. This enables the doctor to evaluate the structure and function of the fetal heart.
Fetal echo cardiogram is recommended if
- mother, father or sibling of the unborn child has congenital heart defect,
- the fetus is diagnosed with genetic abnormality.
- the result of amniocentesis is abnormal.
- mother has taken medications that are known to cause congenital heart disease.
- the mother had disease like rubella during pregnancy.
- heart abnormality suspected during routine ultrasound.
- abnormal fetal heart rate or rhythm.
- mother is suffering from diabetes prior to pregnancy.
- fetus is diagnosed with chromosomal disorders such as Down's Syndrome.
Most heart defects can be corrected through surgery, medicine,artificial valves,pace makers etc. Many of the surgeries are performed before the age of two.
Symptoms of Congenital Heart Defects in New Borns
- Heart murmur.
- Bluish tint in skin and lips.
- Shortness of breath.
- Poor weight gain.
- Congenital Heart Defects
Congenital heart defects involve abnormal or incomplete development of the heart. Learn about the different types of congenital heart defects.
3. Spina Bifida
Also called split spine. In this condition the vertebral bones of the spine do not fuse at some level in the spinal column and the meninges, i.e. the coverings of the brain and spinal cord bulge through the gap. The area may be covered by a thin membrane and may contain nerve roots or the spinal cord itself may be exposed.In mild cases the area may be covered by skin and is marked only by a hairy mole.
Spina bifida occurs due to the defect in the neural tube. Neural tube is the part of the embryo that will ultimately develop into brain and spinal cord.and spinal cord. It forms early in the pregnancy and usually closes by the 28th day after the conception. In case of spina bifida, a portion of the neural tube fails to develop or close properly.
Types of Spina Bifida
1. Spina Bifida Occulta
It is the mildest form with small gaps one or more vertebrae. Since spinal nerves are not affected, the children don't develop any neurological problems. Visible indications are one of the followings:
- a birthmark/dimple.
- a tuft of hair.
- a collection of fat
The condition sometimes remain unknown until discovered accidentally through X-ray or some other imaging test.
The protective membrane around the spinal cord or meninges pushes out through the opening of the vertebrae. Since the spinal cord develops normally, the membrane can be removed surgically with little or no damage to the nerves.
This is the most severe form. The baby's spine remains exposed along several vertebrae in the lower or middle back. Both the membrane and the spinal cord protrude at birth, forming a sac on the baby's back. Since the tissues and nerves are exposed the baby is prone to life-threatening infections. Some neurological problems that may occur are:
- weakness of the leg muscles which may also cause paralysis.
- bowel and bladder problems.
- deformed feet, uneven hip or curved spine.
- fluid build-up in the brain.
Causes are though uncertain, it is believed to be due to a combination of genetic and environmental factors like family history, neural tube defect and folic acid deficiency.
- Take enough folic acid during pregnancy.
- Doctor should be informed if medications for seizures are taken by the mother as these have the potential to cause birth defects.
- Avoid drugs and alcohol.
- Avoid using sauna and hot tub in the first weeks of pregnancy and treat a high fever immediately as rise in body temperature may during this stage may raise the risk of spina bifida.
During pregnancy maternal serum triple or quadruple blood test can be done. If the test result suggests birth defect then amniocentesis can be done to confirm spina bifida.
Children with severe spina bifida usually need surgery. Babies who have water accumulation around the brain may need a shunt to drain out the excess fluid into the belly. Brace, wheelchair or other aids might also be needed.
4. Cerebral Palsy
It is caused by the lack of enough oxygen supply to the brain in the later pregnancy or during labor. Other causes are:
- maternal infections that may affect the fetus.
- infections of the baby that causes inflammations in or around the brain.
- genetic mutations leading to abnormal brain development.
- complicated labor and delivery.
- Rh blood type incompatibility between mother and child.
- Stiff muscles with excessive reflexes i.e spasticity.
- Stiff muscles with normal reflexes i.e rigidity.
- Lack of muscle coordination or ataxia.
- Involuntary movements.
- Slow writhing movements.
- Delays in attaining motor skills.
- Excessive drooling.
- Difficulty walking.
- Delayed speech development.
Unfortunately there is no cure for cerebral palsy. A patient would require life long care and medications.
5. Respiratory Distress Syndrome (RDS)
Lungs of the baby lacks in surfactant - a substance that keeps open the tiny air sacs in lungs through which the oxygen is absorbed into the blood. Since the blood passing through certain portions of the lung is not oxygenated the baby suffers from hypoxia, i.e. lack of oxygen. In severe cases the carbon dioxide level in the blood rises to a dangerous level leading to respiratory acidosis.
Surfactant is not produced in adequate amount in the fetal lungs till about 34th - 36th week of pregnancy. As a result a baby born prematurely has a chance of developing RDS. Other factors that increase the chance of RDS are:
- a sibling with RDS.
- maternal diabetes.
- rapid labor.
- problems in delivery that reduces the blood flow to the baby.
The symptoms are usually apparent within few minutes of birth. These are:
- bluish tint of the skin and mucous membrane.
- brief pause in breathing or apnea.
- nasal flaring.
- rapid breathing.
- shallow breathing.
- grunting sounds while breathing.
It is possible to anticipate RDS prenatally by testing fetal lung maturity. This is done by amniocentesis. Amniotic fluid test includes
- Lecithin/sphingomyelin ratio,
- Foam stability index test,
- Surfactant/albumin ratio
Risk of RDS is high if lecithin/sphingomyelin ratio is < 2, phosphatidyl glycerol is absent, foam stability index < 47, or surfactant/albumin ratio is < 55 mg/g.
With ventilation support alone, surfactant production eventually begins and RDS resolves within a week. But ventilators can damage the lung tissues, hence this treatment should be given only in specific cases like
- high level of carbon dioxide in the blood.
- acidosis, i.e. low blood pH.
- repeated pause in breathing.
Giving extra surfactant to an infant was found to be helpful, but delivering surfactants directly into the baby's airway has some risks involved.
A treatment known as continuous positive airway pressure (CPAP) may prevent the need for assisted ventilation or surfactant in many babies. CPAP sends air into the nose to help keep the airways open. It can be given by a ventilator or with a separate CPAP device.
The condition usually gets worse in first 2 - 4 days and then slowly improves. But some infants eventually succumb between 2 - 7 days. The good news is the mortality rate is < 10%.
6. Pyloric Stenosis
In this condition the ring of muscles or pylorus that links the stomach to the small intestine thickens and narrows, blocking food from reaching the small intestine. Pyloric stenosis can lead to forceful vomiting, dehydration and weight loss.
Symptoms are visible within 2 - 4 weeks. The signs are:
- Projectile vomiting, i.e. the baby vomits forcefully, throwing the milk in a several feet away. Vomiting is mild in the beginning but gradually increases as pyloric stenosis progresses.
- Persistent hunger.
- Wave like contractions of the stomach soon after feeding as stomach muscles are trying to force food through the narrowed pylorus.
- Severe weight loss as the baby is not able to keep down the food
- Ultrasound of the abdomen.
- Barium X-ray reveals swollen stomach and narrowed pylorus if the ultrasound is not clear.
- Blood test shows electrolyte imbalance.
Surgical procedure called pyloromyotomy is used to treat the problem. It is a minimally invasive surgery done by laparoscopy. Recovery is quick and the baby can start taking milk after about 12 hours of surgery. Some vomiting might continue a few days after the surgery.
7. Epispadias and Hypospadias
These are congenital anomalies. In epispadias the penile opening of the urethra is on the upper surface of the penis. The penis may curve upwards.
In hypospadias, the opening is on the underside of the penis, making it curve downwards. It may interfere with fertility in later life if not treated.
As the penis develops in a male fetus, certain hormones stimulate the formation of the urethra and foreskin. Hypospadias results when a malfunction occurs in the action of these hormones, causing the urethra to develop abnormally.
Both the problems can be corrected through surgery.
Trisomy (three bodies) is a chromosomal disorder. Humans normally have 23 pairs (46) of chromosomes, out of which 2 sex chromosomes decide the gender and 44 decide other factors like growth and function. A chromosomal disorder occurs due to the change in number or structure of chromosomes. When a person has trisomy he/she has 47 chromosomes instead of 46.
Addition of extra chromosome occur immediately during conception and prevention is not possible. One of the risk factors is the maternal age. Women conceiving in late thirties onward are likely to have babies with trisomy than younger women.
Down's Syndrome (Trisomy 21)
Down's syndrome is also called Trisomy 21 because the person has 3 copies of chromosome 21 instead of 2. There are 3 types of Down's syndrome:
- Standard Trisomy 21 is the most common type in which the father's sperm or the mother's egg contains the extra chromosome.
- In Mosaic Down's syndrome the extra chromosome spontaneously appears as the embryo develops.
- Translocable Down's syndrome is rare and occurs in 5% of the patients. It is inheritable.
Down's syndrome can be identified by following symptoms:
- flattened face.
- short arms and legs.
- small teeth.
- flat ears set low on the head.
- slanted eyes.
- excess fold of skin on the inside of the eye.
Down's syndrome sufferers usually have learning difficulties, but the degree varies. Many Down's syndrome children are able to lead near normal lives.
Edward Syndrome (Trisomy 18)
The person has 3 copies of chromosome 18 instead of 2. Symptoms of Edward syndrome are:
- cleft lip or cleft palate.
- defects in the kidney,lungs
- smaller skull compared to the body or microcephaly.
- malformations of the hands and feet – including missing thumbs, club feet and webbing between the fingers and toes (syndactyly)
- malformations of the sex organs
These children usually do not survive beyond the neonatal stage.
Patau Sundrome (Trisomy 13)
The person has 3 copies of chromosome 13 instead of 2. Symptoms of Patau syndrome are:
- abnormal opening in the skull.
- malformation of a part of the brain.
- defect in the structure of the eyes.
- cleft lip or cleft palate.
- extra toes or fingers.
- congenital heart disorder.
- malformed sex organs.
These babies too do not survive beyond the neonatal stage.
Symptoms of Trisomy During Pregnancy
- Size of the fetus is smaller compared to the gestational age.
- Less active fetus.
- Smaller placenta.
- Only one artery in the umbilical cord.
- Too much amniotic fluid surrounding the fetus.
- Maternal serum screening
- Amniocentesis where a sample of the amniotic fluid is taken and examined.
- Chronic villi sampling where a sample of cells from the chorion or the tissue that will ultimately become the placenta, is taken and examined.
- Non-invasive prenatal testing (NIPT) is a new type of screening test that measures fetal DNA circulating in the mother’s blood.
9. Talipes Equinovarus
If a baby has talipes or clubfoot he/she is born with foot or both feet pointing downwards at the ankle(equinus). The heel of their feet are turned inwards( varus). The baby's foot happens to be in this position because the Achille's tendon at the back of the heel is very tight and the tendons at the back are also tight.
Cause of talipes is not clearly known, but some of the following may be a cause:
- if one or both parents or siblings have talipes then the risk increases.
- talipes may also have something to do with the position of the baby's foot when the baby is in the womb.
It can affect both feet.
Diagnosis is usually done after the baby is born. But since the technology of USG has improved, it is possible to detect talipes even before the baby is born.
There can be different degrees of foot deformity with talipes. Some babies have milder foot deformity than others. If a baby is diagnosed with talipes, an orthopedic surgeon will often use a grading system to grade the severity of the foot deformity. A common grading system that is used is the Pirani score. With this grading system, a grade from 0 to 6 is given. The higher the grade, the greater the degree of foot deformity.
Major surgery was the common method of treatment. But nowadays a treatment called Ponseti method was found to give a good result.
Check the video link to see how Ponseti method works.
10. Cleft Lip and Cleft Palate
These conditions happen when the upper lip or the palate, sometimes both, don't develop completely. In a cleft lip, the halves of the upper lip fail to join properly as the baby develops. In a cleft palate, the halves of the baby's palate fail to join.
These are most common birth defects. It is possible to have a cleft lip without a cleft palate, a cleft palate without a cleft lip, or both together. The problem can be corrected with surgeries.
It is a condition that cannot be prevented. Cause may be due to one or combination of factors listed below:
- genetic and environmental factors.
- sibling or close relative with the same problem.
- medications taken by the mother during pregnancy. Anti-convulsant drugs, drugs used for treating psoriasis, arthritis etc. have the potential to cause cleft lips/palates.
- exposure to viruses and chemicals while in the womb.
Prenatal USG can sometimes detect cleft palate. If not detected prior to birth, it can be detected after birth when physical exam is done by the doctor.
Less common clefts occur only in the muscles of the soft palate (sub-mucous cleft palate), which are at the back of the mouth and covered by the mouth's lining. This type of cleft often goes unnoticed at birth and may not be diagnosed until later when signs develop. Signs and symptoms of sub-mucous cleft palate are:
- difficulty swallowing as foods tend to come out of the nose.
- nasal speaking voice.
- chronic ear infections.
- dental problems.
Repair of cleft lip requires one or two surgeries. The first surgery is usually performed at 3 months.
Repairing a cleft palate requires multiple surgeries over a course of 18 years. The initial surgery is often done between 6 - 12 months of age.
Children with a cleft palate may also need a bone graft when they are about 8 years old to fill in the upper gum line so that it can support permanent teeth and stabilize the upper jaw. About 20% of children with a cleft palate require further surgeries to help improve their speech. Once the permanent teeth grow, braces are usually needed to straighten the teeth.
Additional surgeries may be required to improve the appearance of the lip and nose, close openings between the mouth and nose, help breathing, and stabilize and realign the jaw. Final repairs of the scars left by the initial surgery will probably not be performed until adolescence, when the facial structure is more fully developed.
Most cases are congenital; some are unknown
May need special equipment to help with mobility; medication needed to control the muscle spasms.
Uncertain but women who smoke or have diabetes have higher risks.
Congenital heart defects
Depending on severity, sometimes surgery are required. Need to have regular check ups.
Most common chromosomal condition related to maternal age > 35
A life long affliction; some cases may require may require special education; many are mainstreamed
Uncertain but linked to genetic or environmental factors as well as folic acid deficiency
There is no cure. Minor cases may not need any treatment; but more severe cases are treated with surgery and medication.