Multiple Pregnancies & Genetic Testing

Multiple Pregnancies 

Multiple pregnancies

Multiple pregnancies occur when more than one egg is released and fertilized casual fraternal twins/more. With multiple pregnancies, you will usually go through the same symptoms as a single pregnancy but more intensely, more painful, and harder to manage. There are two types called identical (monozygotic), non-identical (dizygotic), or fraternal. 

  • Identical: occurs when a single fertilized egg splits into two or more embryos creating same-sex babies (2+ boys or 2+ girls) with the same genes. 
  • Non-identical: occurs when 2+ separate eggs are fertilized with 2+ sperms. They can have the same or different sex. These siblings only share 50% of the chromosomes like any other siblings born at different times. They are more common than identical. 

Causes; There aren’t any concrete explanations for multiple pregnancies. Everyone has a chance, and therefore it doesn’t have to run in the family. However, some studies show non-identical pregnancies are more common in certain ethnic groups (such as more twins for Africans and the lowest chances for Asians) if the mother is 35 years old or above and if it runs on the mother’s side of the family. 

Risk factors: Most multiple pregnancies are healthy with healthy babies, but more risks are associated with them. You have a higher chance of anemia (limited healthy red blood cells to carry enough oxygen to your body’s tissues), pre-eclampsia (high blood pressure (hypertension) and high levels of protein in the urine (proteinuria)), gestational diabetes (elevated levels of glucose in the blood during pregnancy), and having a premature birth where more than half of all twins and almost all triplets & more are born prematurely. 

Pregnancy care: Because these pregnancies have a higher likelihood of growth problems, you will need to visit the doctor more frequently and have more ultrasound exams than a single pregnancy would need. In some cases, one fetus is bigger than the other, called discordant caused by an infection or a problem with the umbilical cord or placenta. However, this doesn’t mean a problem with the babies. With twin pregnancies, there can be vaginal pregnancies that depend on the position, weight, & health of each baby, your health & how the labor is going, and the experience of your doctor. If these conditions aren’t met, then you are more likely to have a cesarean pregnancy for twins or more. 

  • Pregnancy genetic testing (before and after birth)

It aids in identifying if the fetus has a genetic abnormality that can cause health conditions or birth defects. It is available before you give birth (prenatal genetic testing) and after (postnatal genetic testing). All women need to get genetic testing, especially if you or your partner have a family history of a genetic disorder, are above 35 years old, have a child with a genetic abnormality, previous stillborn, more than two miscarriages, or genital infections. There are two types of testing called screening tests performed to identify the women’s chance of having a baby with chromosome abnormalities and diagnostic tests to determine if the fetus has birth defects. 

Prenatal genetic testing: can determine certain genetic conditions. You will give a blood or saliva test (to identify your Rh factor, if you have iron deficiency, diseases such as STD, gestational diabetes, thyroid, etc.), urine test (to measure your glucose, protein, ketones (formed when there is not enough sugar or glucose), and bacteria), and other tests by swabbing your vagina or rectum (to check for signs of infection).

There are different types, but the common ones include carrier screening done on parents to identify certain inherited disorders, prenatal genetic screening done on pregnant women to detect the baby’s defects in the abdomen, heart, & facial features, cell-free DNA/ Non-invasive prenatal screening done on women with an increased risk of health conditions. Carrier screening can be done before or during pregnancy, prenatal genetic screening can be done in the first or second trimester, and cell-free DNA can either be done before or after the first-trimester screening. 

Postnatal genetic testing: is performed on newborns and can determine inherited anomalies, diseases, and developmental delays in children. Newborns undergo genetic screening called a newborn screening to check for specific genetic abnormalities using blood samples. 

Screening is recommended for the different types of a genetic disorders (at least 30). These screening tests differ from country to country. Some tests can be those for hypothyroidism (under activity of the thyroid gland), galactosemia (how your body metabolizes galactose), and sickle cell disease (a severe hereditary form of anemia).