Birth defects: Your questions answered


Birth defects are physical abnormalities or health problems that start while a baby is developing inside its mother's body. Also known as congenital disorders, birth defects can occur at any stage of pregnancy and are caused by a host of factors. Here we cover common areas of concern around birth defects.

While Hannah Middleton was in her mother's womb , her right lower leg and two fingers on her right hand were amputated. Hannah's birth defects were caused by a very rare condition called amniotic band syndrome, where the inside of the placenta is damaged during a pregnancy. This creates fibre-like bands that tangle, attach to or wrap around parts of the baby's body, disrupting blood flow to the area and preventing it from developing properly. In some cases, the bands wrap so tightly around an area that they cause it to be amputated.

Amniotic band syndrome is one of a host of conditions that can cause birth defects. According to the Cleveland Clinic, one out of every 33 babies born in the United States is affected by a birth defect. Globally, 2% to 3% of infants have one or more defects at birth. This goes up to 5% by age one as not all defects are discovered at birth.

What form do birth defects take?

According to material shared by the US Department of Health and Human Services:

Structural birth defects include problems with a structure of the body, like a cleft lip or cleft palate, heart defects, abnormality in the limbs like clubfoot, or neural tube defects that are linked to the growth and development of the brain and spinal cord.

Functional or development birth defects include:

  • Disorders of the brain or nervous system
  • Sensory problems with hearing or sight
  • Metabolic disorders like phenylketonuria (where levels of amino acids normally found in the body are too high) and hypothyroidism (an underactive thyroid gland)
  • Degenerative disorders (like muscular dystrophy), which may not be obvious at birth but which worsen over time as a child ages.

Are birth defects serious?

The impact of a birth defect on a child's life can range from mild to severe, depending on which organ or body part is involved and how severe the defect is.

When are birth defects likely to occur?

According to the US Centers for Disease Control and Prevention (CDC), birth defects are most common during the first three months of pregnancy. However, they can also occur in later stages of pregnancy.

How are birth defects diagnosed?

Ultrasound scans and blood tests done during pregnancy can detect birth defects. Specific screening tests are done in each trimester to look for birth defects. If necessary, the doctor may recommend further diagnostic tests that are more detailed and more sensitive.

Are birth defects always detected as soon as they arise?

No. They can be discovered before a baby is born, at birth, or any time after birth. That's because some birth defects are detectable through the standard tests done during pregnancy. These include clubfoot (abnormal positioning of the foot), neural tube defects, cleft lip (a gap in the upper lip), cleft palate (a hole in the upper palate of the mouth) and Down syndrome. Other conditions, such as heart defects or scoliosis (sideways curvature of the spine), might not be detected until a child is a few months old. An abnormal organ might take years to be diagnosed, and might only be detected when symptoms of the organ malformation become apparent. However, routine pregnancy tests and screening are so important to ensure that any defects that could be picked up early are detected.

What causes birth defects?

For some birth defects, researchers know the cause. However, for most birth defects, the exact cause is unknown. In such cases, the cause is likely a complex mix of factors, which can include the following:

  • Problems with the baby's chromosomes (the structures in our cells that contain our genes): A chromosome or part of a chromosome might be missing, or there may be an extra chromosome (as is the case with Down syndrome).
  • One or more genetic (inherited) conditions: Sometimes genes (a length of DNA that codes for a specific protein in the body) carry a mutation or they are missing a part of the gene that stops them from working properly and results in a health problem. Sometimes entire genes are missing and this causes health problems too. According to the Cleveland Clinic, around 20% of birth defects are caused by genetic factors.
  • A mother's exposures to chemicals or toxins or medicines that can harm her developing child. For example, alcohol misuse can cause foetal alcohol spectrum disorders.
  • Mothers can also become sick while pregnant, and some infections can cause birth defects in the developing child.
  • Poor nutrition in the mother can mean a lack of certain key nutrients, such as folic acid, before and during pregnancy. A lack of folic acid is, for example, a key factor in causing neural tube defects.
  • Multifactorial problems, where a birth defect is caused both by genetic and environmental factors.

Can birth defects be prevented?

Some birth defects are linked to poor nutrition or healthcare on the part of a child's mother. This means that these may be prevented. We can focus on the mother's vaccinations and make sure they are up to date so that she does acquire any avoidable infections that could hurt her baby. We can also ensure her adequate intake of folic acid (folate) and iodine through supplements or the fortification of staple foods.

Are some people at higher risk of having a child with a birth defect?

The risk of a baby developing a birth defect is linked to its family's health history, parents' age and other factors.

According to the US Centers for Disease Control and Prevention (US CDC), being an older mother - typically over the age of 34 - increases the risk of birth defects. So too does having a family member who has a birth defect.

According to the Mayo Clinic, studies have shown that when a father is over 40, there might be a small increase in the risk of adverse pregnancy outcomes or risks to children's health. There is also an increased risk of certain rare birth defects (including defects in the development of the skull, limbs and heart).

The chances that a baby will be born healthy are higher when a mother takes the following measures:

  1. Getting medical conditions she may have under control, ideally before falling pregnant. This is because conditions like diabetes and obesity can increase the risk of birth defects.
  2. Taking a prenatal vitamin with 400 mcg of folic acid if trying to conceive - starting at least a month before getting pregnant
  3. Alerting her healthcare provider as soon as she thinks she may be pregnant
  4. Seeing her healthcare provider regularly during her pregnancy
  5. Not smoking during her pregnancy
  6. Not drinking drink alcohol during her pregnancy
  7. Making sure that any dietary or herbal supplements or medicines (prescription and over-the-counter medicines) she is taking are safe for her developing baby. Some of these items can cause birth defects, which are most severe when used during the first three months of pregnancy.
  8. Avoiding marijuana and any recreational drugs
  9. Preventing infections during pregnancy. Read the US CDC's 10 tips for preventing infections before and during pregnancy.

The US CDC points out that, "Having one or more of these risks doesn't mean you'll have a pregnancy affected by a birth defect. Also, women can have a baby born with a birth defect even when they don't have any of these risks. It is important to talk to your doctor about what you can do to lower your risk."

How are birth defects treated

Usually, children who have birth defects need special care that is unique to their condition. In Hannah's case, it has meant multiple surgeries and the use of prosthetic legs. Overall, possible treatments for birth defects can include physical and speech therapies, surgery, assistive devices like prostheses, and medicines. Children with birth defects will likely need access to a variety of supportive services and specialists.

Are there specific symptoms to be on the lookout for at birth that may indicate a birth defect?

Symptoms of birth defects vary widely and can also differ for each child. According to Stanford Children's Health, they can include things such as:

  • Abnormal shape of head, eyes, ears, mouth or face
  • Abnormal shape of hands, feet or limbs
  • Trouble feeding
  • Slow growth
  • Frequent infections
  • Joint problems
  • Spinal cord not fully enclosed (spina bifida)
  • Kidney problems
  • Heart problems
  • Intestinal problems

How does a birth defect affect the family as a whole?

There is no doubt that having a child with a birth defect impacts the whole family. Parents face unique challenges in caring for the child. They will always feel a desire to make life better for their child and prevent birth defects in the future (an issue that caused Hannah's mother, Nicole, great concern in her second pregnancy ). Parents may feel heightened levels of trauma and even show symptoms of post-traumatic stress disorder, depression or anxiety, so support is fundamental to their wellbeing.

Research shows that parents deal with challenges around:

  • Communication with healthcare professionals
  • Ensuring quality of life for the affected child and family
  • Creating awareness and advocating for research on and funding for the condition their child has
  • Finding resources and support
  • Helping teenage children who live with a birth defect to transition to appropriate adult care.

Of course, all of these issues also affect the growing child. According to the US CDC, it's important to reach out for support in dealing with having a child with a birth defect. Parents can talk to other families with children affected by the same condition, join support groups or chat to healthcare providers to find out about available support services.

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