How Often to Get Ultrasounds

Pregnancy Ultrasound

While there is no absolute rule about how many ultrasound scans a woman should have during pregnancy, as a general rule ultrasound scans are performed at 7, 18, and 32 weeks. At 7 weeks, a pregnancy ultrasound confirms that the woman is in fact pregnant. It can also exclude ectopic or molar pregnancies, measure the crown-rump length of the fetus for the purposes of dating conception, and confirm cardiac pulsation (heartbeat) to make sure the fetus is viable. When an abnormality is suspected, pregnancy ultrasound scans are usually also performed at around 11-14 weeks. These ultrasound scans can measure fetal nuchal translucency, evaluate the fetal nasal bone and detect tricuspid regurgitation. This information is vital in early diagnosis of Down Syndrome.

Ultrasound Scans During & After Second Trimester

At around 18 to 20 weeks, an ultrasound is performed to check for congenital malformations. During the second trimester, the fetus is large enough to provide an accurate representation of his or her anatomy in an ultrasound. Also at this point during pregnancy, ultrasound scans can help to confirm multiple pregnancies and placental position.

After 32 weeks along in pregnancy, ultrasound scans may be done to help evaluate the size and weight of the fetus or to follow up on possible abnormalities that were of concern in an earlier scan. Ultrasounds in the latter part of pregnancy are most commonly used to detect fetal growth retardation. If your doctor suspects that your baby may be suffering from fetal growth retardation, a doppler scan may be used to confirm the diagnosis.

6/4/2007 4:07:45 PM