Important fetal screenings during pregnancy During pregnancy, examinations are necessary to ensure the health of the fetus. These investigations are done through ultrasound and screening tests in the first, second and third months of pregnancy. Stay with us to discuss the most important ones. ### **Fetal anatomy examination sonography** Anatomical structures that can be detected by ultrasound based on gestational age include the following: - Head (including ventricles and blood vessels) - the heart - Stomach - Small intestine - Liver - Bladder and organs Ultrasound can detect abnormal anatomy as well as normal anatomy. The presence of these anomalies can affect the location of birth (for example, delivery room versus pain room, labor, recovery room, or a normal center versus a well-equipped center) and the method of delivery to obtain favorable neonatal outcomes. The number of fetuses and their organ of presentation is also determined by ultrasound and can help in deciding the way of delivery. ### **NT ultrasound** One of the prenatal screening techniques is nt ultrasound, which measures the fluid at the back of the fetus's neck between 10-14 weeks of pregnancy to identify fetal abnormalities. If the fluid volume is more than 2.5 mm, it is considered an abnormal finding, while the size of 3 mm or more indicates a genetic disease or physical anomaly. If nt is abnormal, genetic diagnostic test is recommended. ### **Checking placenta position and its function with ultrasound** The growth pattern of the uterus and placenta and the fullness of the mother's bladder affect the determination of the position of the placenta by ultrasound. During the first trimester, it is difficult to differentiate between endometrium and small placenta. At 14-16 weeks of pregnancy, the placenta is clearly visible, but if the placenta is seen in the connection or the internal hole of the cervix in a low-lying form, this observation may be due to the fullness of the mother's bladder. **For more information on pregnancy ultrasounds, you can contact Dr. Seif's radiology and ultrasound center or visit the doctor's Instagram address. Dr. Saif's ultrasound center contact numbers: 88553310** ### **Detection of unpaired pairs** 15-20% of pregnancies diagnosed by ultrasound in the second trimester as placenta previa, at the time of birth, only 5% of them are placenta previa. Therefore, placenta previa can rarely be detected before the 27th week of pregnancy, which is due to the lengthening of the lower canine with the progress of pregnancy. Another use of ultrasound is to determine placenta maturity. Calcium deposits occur with the progress of pregnancy, which is due to the reduction of maternal blood flow on the surface of the placenta. Due to the existence of this physiological phenomenon, it is not possible to accurately diagnose hypoxia and the danger of the fetus. Anyway, this phenomenon can be seen after 42 weeks of pregnancy and more. ### **amniocentesis test** The safety of amniocentesis increases when the position of the placenta, fetus and amnion sacs can be identified. Ultrasound screening reduces the risks associated with amniocentesis, such as feto-maternal bleeding from a perforated placenta. Sampling of the villi can be done under ultrasound guidance and by determining the position of the placenta and the chorion of the phrendosome.