Ultrasounds use sound waves to obtain images. Real-time imaging is the main sonographic technique that is used for both obstetrical and gynecological ultrasounds.
Obstetrical ultrasounds can be performed during all stages of the pregnancy. Ultrasounds are performed mainly using either a trans-abdominal or trans-vaginal approach.
Most patients typically have at least one ultrasound in the 1st trimester to confirm presence of a viable pregnancy within the uterus and also to help to estimate the gestational age of the fetus. An ultrasound in the 1st trimester of the pregnancy is considered to be the most accurate in estimating the gestational age of the fetus.1st trimester ultrasounds can be done both with a trans-vaginal or trans-abdominal approach depending on what is being evaluated.
Ultrasounds in 2nd and 3rd trimester on the other hand are more commonly done with the trans-abdominal approach, but a trans-vaginal approach may also be used as needed.
Most patients generally receive at least one ultrasound in the 2nd trimester for evaluation of fetal anatomy. According to the American College of Obstetrics and Gynecology, the optimal time for this ultrasound is at 18-22 weeks of gestation. Ultrasonography is considered safe for the fetus when it is used appropriately to help gain medical information important for the pregnancy.
Just like obstetrical ultrasounds, gynecological ultrasounds can also be done via a trans-vaginal or trans-abdominal approach (although the trans-vaginal approach is usually more commonly used).
An additional type of gynecologic ultrasound that can also be performed at our office is the saline infusion sonohysterography (SIS). This ultrasound involves fluid being infused into the uterine cavity through the cervix to help provide improved visualization of the endometrial cavity/lining during a trans-vaginal ultrasound.