An Overview of Prenatal Genetic Testing

An Overview of Prenatal Genetic Testing

Source: scottdinesen

A Guide on the First Trimester Prenatal Screening

The early months of pregnancy require women to start planning for the birth of their children. It also begins a series of doctor's appointments and tests, such as prenatal tests.

Doctors use prenatal blood tests and ultrasounds to check the baby's development during the first trimester. They obtain blood samples from the mother to measure two chemicals called pregnancy-associated plasma protein A (PAPP-A) and human chorionic gonadotropin (hCG).

During the early months of pregnancy, the placenta produces a protein called PAPP-A, which rises during the first trimester. Abnormally low levels indicate an increased risk of chromosomal abnormalities in the fetus, such as Down syndrome (trisomy 21) and Edwards syndrome (trisomy 18). Typically, the baby receives two copies of each chromosome: one from the father and another from the mother. The baby has three copies of the same chromosome in these abnormalities, leading to developmental problems.

The placenta also produces another hormone, hCG. While hCG levels naturally rise during the first trimester, reaching a peak around weeks 8-10, excessively high or low levels can also indicate a potential risk for chromosomal abnormalities in the baby.

By analyzing the levels of both PAPP-A and hCG, healthcare providers can gain an initial picture of the baby's development. However, the results don't necessarily provide a final diagnosis.

The nuchal translucency (NT) scan is another important prenatal screening test. Regular ultrasounds show the whole baby, but this special ultrasound scan zooms in on the back of the baby's neck. Doctors measure the amount of fluid in this area; its thickness can indicate abnormal development.

Ideally, the measurement should fall within a specific range for the fetus's gestational age. An increased nuchal translucency thickness above the established norm serves as a marker for potential chromosomal abnormalities like Down syndrome or Edwards syndrome. Extra genetic material characterizes these conditions, which can sometimes cause fluid buildup in the nuchal translucency area.

An increased nuchal translucency thickness can also mean a higher risk for heart malformations. While not directly related to chromosomes, these defects can sometimes disrupt normal fluid flow within the fetus, leading to a thicker nuchal translucency.

Nonetheless, increased nuchal translucency thickness doesn't indicate a problem. Several factors, including maternal age and ethnicity, can influence the measurement. To determine an overall risk profile, healthcare providers will consider the NT measurement, blood test results, maternal age, and other relevant medical history.

Moreover, the first-trimester screening only provides a risk estimate for chromosomal abnormalities; an abnormal result doesn't necessarily mean a problem with the baby. However, it does warrant further investigation through diagnostic tests like chorionic villus sampling (CVS) or amniocentesis. These tests are more invasive as they involve sampling fetal tissue, so mothers need to consult their doctors before making the decision to proceed with them.

Further tests can confirm the diagnosis of chromosomal abnormalities. If medical professionals confirm chromosomal abnormality, they will recommend that the parents undergo genetic counseling. The counseling can help parents understand the implications for their baby's health and guide them in making informed decisions about the pregnancy. Knowing about potential challenges allows parents to start planning for a child with special needs. It might involve connecting with support groups and exploring available resources.

Source: scottdinesen

Important Aspects of Prenatal Health Care

 

Prenatal health care is a term used to describe the various health services a person receives while they are pregnant. Common examples include prenatal testing and routine checkups during pregnancy. Families are advised to learn about and begin practicing prenatal care as soon as possible. One of the first steps of prenatal care involves contacting a physician to confirm the pregnancy. Two basic elements of prenatal care are to follow the doctor’s advice on all prenatal health matters and to keep up with prenatal care for the duration of the pregnancy, without missing any checkups or appointments.

Some families may wonder if prenatal care is necessary, or if they can go through a pregnancy while only following the most basic guidelines for prenatal care. Proper prenatal care is paramount to the safety of both the mother and their child. According to the National Institutes of Health, between nine and 10 percent of women in the United States experience some type of acute maternal complication, which equates to about 14 million women each year. Complications can range from minor to severe. The absence of prenatal care can lead to more serious complications, while families who practice prenatal care can identify and treat complications before the child is born.

Individuals and families interested in getting pregnant can initiate prenatal care before pregnancy begins. This phase of prenatal care is known as preconception health. There are many different elements of prenatal care, ranging from eating a healthier diet to testing for potential risk factors and health conditions that could impact the pregnancy. Specific examples of preconception care include taking between 400 to 800 micrograms of folic acid every day for a minimum of three months before conception, managing health issues such as asthma and diabetes, and consulting with a physician about any medications the expecting mother is taking.

Families can practice certain aspects of preconception care even if they have no immediate plans for a pregnancy. For example, there is no harm in taking folic acid supplements. Furthermore, individuals may be pregnant for several days, weeks, or even months before they realize it, meaning it may be too late to enjoy the full benefits of folic acid.

Following conception, families begin the prenatal care stage. Again, prenatal care should begin as soon as possible, even if the mother has already experienced several healthy pregnancies. Each person’s pregnancy is different, meaning individuals must regularly discuss their overall health with a doctor. Physicians can provide insight into the many different elements of prenatal health, such as foods to avoid, lifestyle changes that should be made, and how to ensure that the family’s living environment is conducive to a healthy birth.

While some women may need to see doctors more frequently, a standard prenatal health plan involves monthly visits through the first 28 weeks, bi-weekly appointments for the next nine weeks, and weekly visits for the remainder of the pregnancy. Women over the age of 35 or women who are at risk for birth complications should see their doctors more often. Individuals in their late 30s or early 40s typically give birth to healthy children but must prioritize all aspects of prenatal health.

Finally, individuals may qualify for access to reduced-cost or cost-free prenatal care. More information about prenatal health resources can be found by calling 800-311-BABY, a toll-free number that puts families in touch with the local Health Department.