Fetal ultrasound detects bone and limb abnormalities

MSc. Dr. Ha To Nguyen, Director of the Center for Fetal Medicine, Tam Anh General Hospital, Ho Chi Minh City, said that bone and limb malformations are among the most common congenital abnormalities of the fetus. This is a group of diseases with isolated mild abnormalities such as clubfoot, polydactyly… that do not affect the development of the fetus. However, if accompanied by other structural malformations, related to gene mutations, it can cause death in the womb or immediately after birth.

Ultrasound is the basic means of screening for fetal abnormalities. Some severe and fatal skeletal dysplasias can be diagnosed in the late first trimester. Most skeletal and limb abnormalities are detected by morphological ultrasound at 18-22 weeks. In the third trimester, examining the fetal limbs is more difficult due to the baby’s position, the hands are often clenched, and the amount of amniotic fluid is reduced compared to the size of the fetus.

Ms. Nhan, 32 years old, was pregnant with her first child. The ultrasound doctor diagnosed the fetus with skeletal dysplasia and the pregnancy had to be terminated at 18 weeks. During her second pregnancy, she was worried that her child might have the same disease.

According to Dr. Nguyen, skeletal dysplasia is a rare group of diseases with many phenotypes, different in prognosis (predicting the possibility of disease development) and recurrence rate. Therefore, Ms. Nhan was prescribed an ultrasound from the first three months of pregnancy to screen for early malformations, and at the same time, perform screening tests for chromosomal abnormalities.

In the second trimester, Ms. Nhan had an ultrasound to assess the fetus’s skeletal system and limbs in detail. If there are abnormalities on the ultrasound that are suspected to be related to skeletal dysplasia, the pregnant woman needs to have an amniocentesis to determine the cause and assess the prognosis of whether the pregnancy can be continued or terminated.

Amniocentesis is a procedure in which a needle is inserted into the amniotic sac to withdraw a small amount of fluid surrounding the fetus. This fluid contains the fetus’s genetic material. Analysis of the amniotic fluid sample can identify gene mutations associated with bone abnormalities on ultrasound.

Dr. Nguyen Do Trong, Pediatric Surgery Specialist, Tam Anh General Hospital, Ho Chi Minh City, said that early treatment of bone and limb deformities can improve the quality of life and overall health of children. Currently, the Pediatrics Department of the hospital in Ho Chi Minh City performs plastic surgery on about 20 cases of polydactyly each year.

To have a healthy pregnancy, couples should have pre-marital and prenatal checkups to screen for genetic diseases. When pregnant, pregnant women need to follow regular prenatal checkups. Pregnant women should also eat and live a healthy lifestyle, supplementing with necessary vitamins and minerals. Do not drink alcohol, smoke or be exposed to secondhand smoke. Avoid taking over-the-counter medications during pregnancy and limit exposure to toxic substances.