An ultrasound during pregnancy is a means of learning about the pregnancy, the fetus and the mother. Though these minimally risky scans can reveal a significant amount of information, they don’t tell all and their accuracy may in part depend on the person interpreting the results. There’s debate about when women should have an ultrasound during pregnancy. Different times are suggested, with additional advice that no more ultrasounds than are necessary should be performed. In general, a few guidelines exist that are routinely followed by most doctors and sometimes doctors recommend more than one ultrasound for varying reasons that depend on the individual pregnancy.
An early ultrasound during pregnancy is performed during weeks five through seven. At this time, the sonogram can reveal presence of the baby in the uterus, and rule out no pregnancy or ectopic pregnancy. Very early problems like threatened miscarriage could also be diagnosed at this time. Some physicians feel these early ultrasounds aren’t necessary for most pregnant women, and instead recommend sonograms during this time only if there is suggestion of problems like suspected ectopic pregnancy or maternal bleeding.
The next possible window for ultrasound during pregnancy, though they can truly be performed at any time, is between roughly the 11th through 14th weeks. At this time, fetal heartbeat can be visualized and scans of the thickness of the fetal neck can be performed as possible diagnosis of Down syndrome. A sonogram at this point allows for women to determine the health of the baby or determine whether they are interested in terminating the pregnancy based on findings. This time period still may not catch other congenital anomalies that could show up in the fetus as it continues to evolve and grow, and any diagnosis of Down’s must be verified with other tests.
Many women first experience ultrasound during pregnancy between the 18th through 22nd weeks. Due to the baby’s larger size and development, it’s easier to catch certain defects like major heart or limb problems. Fetal measurements can also indicate problems or suggest fetal health. Gender is usually fairly predictable at this point, though technicians can be wrong. Other important measurements take place during a midway point ultrasound. Levels of amniotic fluid can be checked and the uterus scanned for any features that might complicate pregnancy or delivery.
Additional ultrasounds later in the pregnancy may be recommended to gauge fetal size, health, or position. Any physical problems in the mom at any point could indicate evaluating both fetus and mom via this test. Should any tests show fetal anomalies, doctors might want further sonogram studies like a level II ultrasound, which is much more extensive, or a fetal echocardiogram to study the fetal heart. Ultimately, the number of ultrasounds and exactly when they occur is based on physician recommendation and any patient health concerns. Seeking the guidance of an experienced obstetrician during pregnancy helps to determine the appropriateness of ultrasound and its timing.