Birth Defects and Congenital Anomalies | Diagnosis & Treatments
How are birth defects diagnosed?
Some birth defects can be diagnosed before birth through ultrasound, amniocentesis, or chronic villus sampling (CVS). Most women have blood tests to screen for their risk of having a baby with a specific birth defect, such as Down syndrome and spina bifida. While it does not usually lead to a cure for the baby's birth defect, prenatal diagnosis can prepare the parents emotionally and help them prepare for a child with a birth defect.
In other cases a birth defect is diagnosed after birth through physical examination or a blood test that screens for several disorders in newborns.
What is a preconception examination?
A preconception examination, also known as a preconception visit, is one of the best ways to ensure a healthy pregnancy. The goals are to assess your overall health and identify any risk factors that can complicate a pregnancy. A preconception examination can include any of the following:
Family medical history
A doctor will assess the medical history of both of your biological parents to see if any family member has had medical problems such as high blood pressure, diabetes, or mental retardation.
Genetic testing
A doctor will assess any possible genetic disorders that can be passed down to your child; some genetic disorders can be detected by blood tests before pregnancy.
Personal Medical History: to determine if you have any medical conditions that may require special care during pregnancy (anemia, epilepsy, diabetes, high blood pressure); to gather information about previous surgeries; and to obtain information about past pregnancies such as complications, losses, and length of gestation.
Vaccination status
To assess immunity to diseases such as rubella (German measles) that can cause miscarriage or birth defects, a vaccine can be given at least three months prior to conception to provide immunity.
Infection screening
Infection screening determines if a woman has a sexually transmitted infection, a urinary tract infection, or another type of infection that can be harmful to her or to the fetus.
What are the treatment options for birth defects?
Most birth defects cannot be cured. Treatment focuses on managing the symptoms. In some cases, however, there are ways to treat specific birth defects.
Gene therapy
Gene therapy replaces a gene that is either missing or defective. Severe combined immunodeficiency diseases (SCID) are a group of very rare diseases for which gene therapy has been used.
Enzyme replacement therapy
Enzymes are proteins for which genes code. So when a gene is mutated and does not produce the gene product, an enzyme is missing or defective. One way to treat this type of genetic defect is to replace the enzyme that the gene is not producing. An example of a condition for which enzyme replacement therapy has been developed is Gaucher disease.
Prenatal treatment
Some birth defects can be diagnosed and treated before birth. Prenatal surgery, for instance, can treat babies with urinary tract blockages and rare lung tumors.
How we care for birth defects
The Fetal Care and Surgery Center is one of a handful of comprehensive fetal care centers in the United States, and the only one in New England. The MFCC treats, supports, and manages complicated fetal anomalies. Its doctors were the world's first to perform life-saving cardiac interventions, such as treating heart problems in utero. The center is also advancing treatments for congenital diaphragmatic hernia, a condition in which a baby is born with a hole in the diaphragm or no diaphragm at all.
Birth Defects and Congenital Anomalies | Research & Clinical Trials
Predicting a drug's likelihood of causing birth defects
When pregnant women need medications, there’s often concern about possible effects on the fetus. Although some drugs are clearly recognized to cause birth defects (thalidomide being a notorious example), and others are generally recognized as safe, surprisingly little is known about most drugs' level of risk. Researchers in the Boston Children's Hospital Informatics Program (CHIP) have created a preclinical model for predicting a drug's teratogenicity (tendency to cause fetal malformations) based on characterizing the genes that it targets.
The model used bioinformatics and public databases to profile 619 drugs already assigned to a pregnancy risk class, and whose target genes or proteins — over 7,000 in all — are known. For each drug, CHIP investigators Asher Schachter, MD, MMSc, MS, and Isaac Kohane, MD, PhD, identified the number of targeted genes likely to be involved in fetal development, using telltale search terms like "genesis," "develop," "differentiate," or "growth." The drugs targeting a large proportion of genes associated with fetal development tended to be in the higher risk classes.
Based on the developmental gene profile, the researchers created a model that showed 79 percent accuracy in predicting whether a drug would be in Class A (safest) or Class X (known teratogen). "We can't provide a yes/no answer,” says Schachter, “but we found a pattern that can predict which are riskier."
Schachter and Kohane believe their model may be of interest to drug developers and prescribing physicians, and might provide useful information to incorporate in drug labeling. (Reproductive Toxicology, March 2011)
