Pregnancy brings much happiness to an expecting couple, with much emphasis being put on staying healthy and looking after oneself. Technology has moved ahead by and large to cover major parameters of the pregnancy and likewise a variety of different prenatal tests are performed on a pregnant woman in order to constantly monitor her state of health as well as the health of the baby. In general, three types of tests are conducted during pregnancy. The first one is to validate the pregnancy using a pregnancy home kit, the second is screening tests and third category is diagnostic tests. The sampling procedures for diagnostic tests can involve either invasive or non invasive prenatal paternity testing.
Screening tests during pregnancy
Screening tests are given to almost all pregnant women and are considered very important. Every pregnant woman will undergo genetic screening testsat fixed points throughout her pregnancy. Some examples would include prenatal testing to verify cholesterol levels in women who have no symptoms of heart problems, or a hormone test to ensure that the woman has enough progesterone being produced by the body etc. Once a woman displays a
symptom of a certain condition, a screening test may become much more meaningful. Screening tests during pregnancy are broadly divided into two phases: First trimester screening tests are done during the first 11-14 weeks of pregnancy. Nuchal translucency (NT) screening test is done using an ultrasound to determine the thickness and level of fluid accumulated behind the foetal neck, determining the probability that the fetus has Down ’s syndrome.
Another first trimester screening includes two maternal serum screening tests (MSST). Plasma protein screening test detects level of pregnancy associated plasma protein (PAPP) produced by placenta in early stages of pregnancy. An increased level may cause risks of abnormal chromosomes. The other test is to measure the level of human chorionic gonadotropin hormone, again produced by placenta in early stages of pregnancy. An increased level may also cause chromosome abnormalities. Second trimester screening: Second trimester screening tests are done during 19-25 weeks of pregnancy.
During the second trimester test an ultrasound is performed to monitor the overall development of the baby and to measure the size and position of the baby (fetal biometric measurements). Along with it, blood tests are conducted to measure the levels of alpha-fetoprotein, human chorionic gonadotropin hormone, estriol hormone and inhibin-A hormone present in the mother’s blood during pregnancy. The combined results of blood tests and ultrasound done during second trimester screening help to detect any risk of chromosomal defects. What happens in cases where screening tests suggest the presence of a hereditary diseases or chromosomal abnormality, is that the OBGYN will recommended further diagnostic tests which can confirm with better accuracy whether the unborn baby will suffer from the disease