What is Prenatal Screening?
Prenatal screening is an essential part of the recipe for ensuring the healthiest mother and baby. prenatal testing These tests are routinely done once a woman conceives. However, when you are ‘planning’ to become pregnant through fertility treatment, we often recommend some of this screening even before you conceive. This way, you have the advantage of treating any abnormalities first—maximizing your chance of having the very healthiest pregnancy. For instance, screening is recommended for infectious diseases such as HIV and hepatitis, which can be particularly harmful if passed on to the baby. We also recommend testing to make sure you are immune to certain diseases such as rubella (aka German measles), which if contracted during pregnancy can cause miscarriage or birth defects. If you are at risk of having diabetes, we also recommend screening for this as it can cause birth defects and fetal demise if it’s not well controlled at the time of conception, not to mention complications with your baby’s delivery.
With many couples conceiving at an older age and heightened awareness of possible genetic risks, greater focus is being placed on screening for genetic defects like Down syndrome. This type of screening begins in the first trimester. Even if a couple chooses not to terminate a genetically abnormal pregnancy, most feel that the extra preparedness is very helpful when planning to raise a special needs child.
Current screening methods for genetic abnormalities are accurate and non-invasive, meaning that they do not put the pregnancy in any danger of miscarriage. Prenatal ultrasound in the first or second trimester is also important to identify any fetal medical conditions that could be treated in the prenatal period or immediately after birth.
An exciting new advancement in prenatal screening is called cell-free DNA testing. We now have technology to distinguish the baby’s DNA in the mother’s blood, allowing us to test for genetic abnormalities in the fetus through a simple blood sample from the mother. This type of screening is almost 99% accurate, and will often negate the need for more invasive testing.
What is Preimplantation Genetic Screening?
For couples going through in-vitro fertilization, we can now screen embryos to ensure the transfer of a genetically normal embryo. The process involves removing several cells of the embryo for genetic analysis before it is transferred into the uterus. It can be used to prevent the birth of a baby with certain types of diseases, such as Cystic Fibrosis or Muscular Dystrophy. It can also be used to reduce the risk of miscarriage in couples with recurrent pregnancy loss, by ensuring the transfer of genetically normal embryos. As of yet, It is not recommended for all couples undergoing in-vitro fertilization because it is not clear whether overall pregnancy rates are improved.
Whether your prenatal screening involves an embryo biopsy during the in-vitro fertilization process or simply bloodwork in the first trimester, participating in the process will optimize your chance of having the safest pregnancy and healthiest newborn baby.