Why genetic testing is essential to reduce the risk of birth defects

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Genetic testing plays a crucial role in reducing the risk of birth defects by providing valuable insights into an individual's genetic makeup. By identifying potential genetic mutations and abnormalities, parents can make informed decisions about family planning and prenatal care. This proactive approach not only helps in reducing the likelihood of passing on hereditary disorders but also allows for early intervention and management of health conditions that may impact pregnancy outcomes.

Dr Priya Deshpande, consultant of maternal foetal medicine, at Motherhood Hospital, Kharghar shares key insights.

Genetic testing empowers people with valuable information that can influence lifestyle choices and medical decision-making. For instance, couples who are aware of their carrier status for specific genetic diseases can consider antenatal diagnostic testing by chorion villous biopsy or amniocentesis to detect the genetic mutation in the present pregnancy. In severe cases, family planning options such as adoption or using donor gametes can be considered. By embracing the benefits of genetic testing, expecting couples willing to start a family can proactively work alongside doctors to optimise their reproductive journey and pave the way for healthier generations to come.

Birth defects can arise from a variety of factors, including environmental and genetic influences. Environmental factors such as exposure to harmful substances or maternal health conditions like diabetes can heighten the risk of birth defects. This exposure may stem from maternal infections, drug and alcohol abuse, radiation or chemical exposure. On the other hand, genetic factors such as mutations in a baby's genes or chromosomes can also lead to birth defects. These genetic abnormalities may be inherited from parents or occur spontaneously during conception. A large number of individuals with birth defects have an identified genetic cause, although this percentage varies depending on the type of defect.

Many birth defects result from a complex interplay of genetic and environmental factors, making it difficult to pinpoint a single determinant. Here comes the role of a foetal medicine specialist and geneticist in evaluation and counselling.

Identification of birth defects
Some birth defects can be detected either during pregnancy or after the baby is born. Prenatal ultrasound imaging is a non-invasive method used to detect and identify potential birth defects.

During pregnancy, the nuchal translucency (NT) ultrasound looks for excess fluid behind the baby's neck along with an array of other markers that can determine the risk of chromosomal disorders. The anomaly scan by ultrasound, typically done around 18-20 weeks, assesses the baby's size and screens for potential birth defects or complications.

Genetic screening by high-resolution ultrasound and serum biochemistry i.e. blood tests are essential in assessing the risk of chromosomal conditions that can lead to birth defects. Diagnostic tests such as chorion villous sampling (CVS) and amniocentesis are performed when screening results indicate a higher risk or abnormalities.

Prevention of birth defects
While it's not possible to eliminate the risk of birth defects, careful planning before conception is essential for reducing their occurrence. This includes maintaining overall health through a balanced diet, managing pre-existing conditions, avoiding harmful substances, and seeking advice from doctors.

For instance, taking folic acid supplements before conception is highly recommended as it helps minimise the risk of certain birth defects, particularly neural tube defects. If there's a family history of birth defects, discussing this with the expert can help identify any additional recommendations or precautions that may be necessary.

Carrier screening is another option as this genetic test examines the DNA of prospective parents to determine if they carry a gene that could cause a genetic disorder leading to birth defects. Being a carrier means having a faulty gene that can be passed on to children, even if the parents themselves do not have the disorder. The results of this screening can indicate if there's a risk of passing on a genetic condition to future children, potentially resulting in birth defects.

Once a woman becomes pregnant, it is essential to prioritise early and consistent prenatal care to identify and address potential risk factors. This involves avoiding harmful substances like tobacco, alcohol, and illicit drugs, as well as embracing a healthy lifestyle that includes a well-balanced diet, regular physical activity, and effective stress management. Attending prenatal visits, adhering to recommended screening and diagnostic tests, and following the guidance of experts are also crucial components of prenatal care.

Additionally, genetic screening tests such as non-invasive prenatal screening (NIPS) or other first and second-trimester screenings can help assess the risk of chromosomal conditions that may lead to certain birth defects. While we may not have complete control over preventing birth defects, adopting a healthy lifestyle, seeking appropriate medical care before and during pregnancy, and undergoing genetic counselling and testing, when necessary, can help mitigate these risks.

Disclaimer: This information does not replace professional medical advice. Consult a qualified specialist or your physician for personalised guidance.