Congenital disorders
What Birth Defects Cannot Be Detected During Pregnancy?
Aug
While prenatal screening and diagnostic tests detect most birth defects, there are many conditions that simply can’t be diagnosed during pregnancy because of the nature of the condition.
Having a baby is an exciting journey filled with hopes for a healthy child. Many potential issues are discovered before birth thanks to advances in prenatal screening. But, some birth defects, or congenital conditions, may only be diagnosed or show signs after your baby is born.
About 3% of babies in the United States are born with a birth defect, and many of those are diagnosed after birth.
Learn more about birth defects.
Language matters
While “birth defect” is a medical term, it doesn’t mean that an individual is “defective.” It refers to health conditions that develop in a baby before birth. Still, the term can be offensive and feel hurtful.
Other terms that may be used include:
- congenital conditions
- congenital (present at birth) abnormalities
- physical malformations
Some of these terms may feel insensitive as well. In an attempt to be accurate and sensitive, we try to use the terms “congenital condition” or “condition present before birth” as much as possible. Also, when we are directly citing research results and studies, we use the terms in the published research study.
What birth defects cannot be detected during pregnancy?
Birth conditions can affect your baby’s health, how their body functions, and sometimes, their physical appearance.
Many birth conditions can be identified with prenatal testing. But, it’s impossible to diagnose every condition a baby may have during pregnancy.
There are certain types of birth conditions that don’t appear on prenatal imaging tests such as an ultrasound, including these types:
Developmental and functional conditions
Congenital conditions that affect the functioning of an organ or a body system and that may not be diagnosed during pregnancy include conditions such as:
- Degenerative disorders: These disorders get progressively worse over time as a child ages, and they may not be obvious at birth. They include conditions such as Rett syndrome and muscular dystrophy.
- Sensory conditions: Sensory conditions that may not be diagnosed before birth include things such as blindness, hearing loss and deafness.
- Metabolic disorders: Metabolic disorders happen when chemical reactions and functions in the body don’t function properly. A few most common metabolic disorders include hypothyroidism, phenylketonuria (PKU), and Tay-Sachs disease.
Structural conditions
Structural congenital conditions are changes in the way an organ is formed or develops. Some of the most common structural changes diagnosed at or after birth include:
- some congenital heart defects
- malformations of the anus and rectum
- hypospadias
- craniofacial abnormalities such as cleft lip and cleft palate
- birthmarks such as congenital hemangiomas
- other skin conditions
Other congenital conditions
The list of undiagnosed congenital conditions during pregnancy is much longer if prenatal genetic screening and diagnostic tests aren’t completed.
How are birth defects diagnosed after birth?
While prenatal testing is used to diagnose congenital conditions during pregnancy, a newborn screening and a physical examination are performed shortly after birth to look for other congenital conditions. In the United States, hospitals are legally required to screen all newborns for several conditions.
These newborn evaluations include a physical exam performed by a pediatrician and a mandated test called a Newborn Screening and it includes:
- Blood screen (heel stick): A newborn blood screening is generally done before your baby is discharged from the hospital. Using a few drops of blood collected from a prick to your baby’s heel, this test checks for certain genetic, endocrine, and metabolic disorders, including:
- biotinidase deficiency
- congenital adrenal hyperplasia
- cystic fibrosis
- galactosemia
- homocystinuria
- hypothyroidism
- maple syrup urine disease
- medium-chain acyl CoA dehydrogenase deficiency and other fatty acid oxidation disorders
- mucopolysaccharidosis
- organic acid disorders
- PKU
- Pompe disease
- severe combined immunodeficiency
- sickle cell disorders
- spinal muscular atrophy
- urea cycle disorders
- X-linked adrenoleukodystrophy
- Hearing screening: Before leaving the hospital, your baby will be given a hearing test.
- Critical congenital heart disease screening: This test starts with pulse oximetry, a painless test that detects the oxygen level in a baby’s blood. If this test result is abnormal, more cardiac tests will be done.
Can you prevent birth defects?
The cause of a birth defect is often unknown. Factors that cause congenital disabilities include:
- inherited conditions
- chromosome changes
- environmental exposure to harmful substances
- combination of factors
In most cases, there’s probably a complicated interaction of environmental and genetic components. Most congenital issues aren’t caused by anything you did or did not do.
That said, you can do a few things to help prevent some developmental irregularities. The most critical steps for prevention include the following:
- Manage chronic health conditions before and during pregnancy.
- Receive recommended vaccinations.
- Avoid harmful substances such as alcohol and tobacco.
- Take a prenatal vitamin with folic acid.
- Review all medications and supplements with your healthcare team.
- Maintain a moderate weight.
- Receive regular prenatal care.
- Avoid travel to areas with Zika.
- Avoid exposure to infections such as toxoplasmosis and cytomegalovirus.
What’s the outlook for pregnancy if the baby has a birth defect?
Regardless of when a congenital condition is diagnosed, its severity can range from minor cosmetic issues to more significant challenges. Early treatment and intervention are essential to prevent further health problems.
A team of medical experts works together to develop personalized treatment plans for babies with congenital conditions, focusing on their unique needs.
Frequently asked questions
Are all birth defects treatable?
No, not all birth defects are treatable. It depends on the type and severity of the condition. Some congenital disabilities require ongoing management and support.
What emotional and psychological support is available for parents coping with a child with a birth defect?
Parents facing the challenges of raising a child with a congenital condition may experience various emotional and psychological stressors. Local support groups, online communities, and counseling services can provide valuable support and a community for parents.
How does family history play a role in the likelihood of birth defects?
Some birth defects have a genetic component. There may be an increased risk of a specific congenital disability affecting your children if it runs in your family. Genetic counseling can help you determine these risks and provide guidance.
The takeaway
While you may become aware of congenital conditions during pregnancy, you may not discover them until your baby is born or later in life. One of the most common conditions diagnosed after your baby is born is a congenital heart defect.
Having prenatal screening and diagnostic tests can identify many defects early on and help you to prepare. Not all congenital disabilities can be avoided, but maintaining a healthy lifestyle and having regular prenatal care can improve the odds of a healthy baby.
