How frequently should a B-ultrasound be performed during the late stages of pregnancy?

Pregnancy Ultrasound Examinations During the Late Stages

As the third trimester of pregnancy progresses, the delivery date draws near, and expectant mothers eagerly anticipate the arrival of their little ones. Additionally, the frequency of prenatal examinations increases significantly. During these check-ups, an ultrasound scan is inevitably conducted, as it provides a vivid picture of the fetus's growth and development. So, when is the best time to undergo an ultrasound during the late stages of pregnancy, and how often should it be done?

When is the Best Time for an Ultrasound in the Late Stages of Pregnancy? Why?

During the late stages of pregnancy, typically, three ultrasound scans are recommended. One is around weeks 30-32, another at week 36, and the last one before delivery.

1. Ultrasound at Weeks 30-32: Fetal Position Check

During weeks 30-32, healthcare providers will measure the fundal height and abdominal circumference of the expectant mother, palpate the abdomen to assess the fetal position, and then conduct an ultrasound to confirm if the fetal position is normal. If the fetus is in an abnormal position, the doctor may recommend exercises such as the knee-chest position or other maneuvers to correct it. If the fetal position remains unchanged by week 34, cesarean delivery may be considered.

2. Ultrasound at Week 36: Focus on Umbilical Cord, Amniotic Fluid, and Placenta

At week 36, expectant mothers undergo fetal heart monitoring and an ultrasound scan. This scan assesses the fetus's growth, checks for umbilical cord缠绕 around the neck, confirms amniotic fluid levels, and evaluates placental maturity.

3. Ultrasound Before Delivery: Assessing Intrauterine Conditions and Determining Delivery Mode

This is the last ultrasound scan before delivery, aiming to comprehensively assess the fetus's condition within the uterus. It finalizes the fetal position, size, placental maturity, presence of umbilical cord缠绕, and amniotic fluid clarity. Based on these findings, the doctor decides whether vaginal delivery or cesarean section is appropriate. Factors such as a normal fetal position, appropriate fetal size, and normal maternal pelvic shape and size favor vaginal delivery. However, cesarean section may be necessary if the fetus is in an abnormal position, too large, or the mother's pelvis is too narrow. Additionally, mothers with special circumstances can opt for ultrasound scans as needed, prioritizing maternal-fetal safety.