It is well known that transvaginal ultrasonography or TVS is one of the common auxiliary examinations in gynecology and is widely used. But most pregnant women still have some doubts or concerns about whether they can have TVS during pregnancy. Here is some common knowledge about TVS during pregnancy.

1. How is TVS performed for pregnant women? Will the vaginal probe touch the fetus during TVS?

As with the procedure of the examination during non-pregnancy, pregnant women need to avoid overfilling of the bladder before undergoing TVS. The doctor will put a disposable condom on the vaginal probe and put it into vagina for examination.

During TVS, the vaginal probe is placed in the vagina, while the fetus is located in the uterine cavity. The cervix will play a protective role and the probe will not touch the gestational sac and fetus at all.

2. What does TVS mainly check?

According to different stages of pregnancy and examination requirements, TVS can focus on examining different content.

(1). First trimester of pregnancy: TVS can help doctors and pregnant women better understand the relationship between the gestational sac and the inner mouth of the cervix, the relationship between the gestational sac and cesarean scar, determine the position and number of the gestational sac, exclude ectopic pregnancy and observe whether there is hematocele beside the gestational sac.

(2). Second trimester of pregnancy: TVS can observe the condition in the cervical canal and the position of the lower edge of the placenta; it can measure the length of the cervical canal more accurately; it can evaluate whether there is cervical incompetence in pregnant women; it can also help doctors further follow up the cervical changes in pregnant women who have undergone cervical cerclage.

(3). Third trimester of pregnancy: Compared with abdominal ultrasounds, TVS can more accurately observe the situation of the upper part of the cervix, and help doctors diagnose some obstetric emergencies that may occur in the third trimester of pregnancy, such as placenta previa, vascular previa and umbilical cord pre exposure, so as to choose a safe delivery mode.

3. Is there any contraindication for pregnant women to receive TVS?

Strictly speaking, there is no absolute contraindication for TVS during pregnancy, but for situations such as a large amount of bleeding, or when pregnant women do not cooperate, doctors can consider changing the examination method -- and using a combination of transabdominal ultrasonography and transperineal ultrasonography, as appropriate.