Nuchal Translucency / Nasal Bone

A nuchal translucency (NT) ultrasound is a type of prenatal screening that can provide important information about your developing baby's health.

One of the primary purposes of a nuchal translucency (NT) ultrasound is that is can be used to detect potential chromosomal abnormalities — birth defects — such as Down syndrome. By measuring the thickness of the fluid at the back of your baby’s neck, your healthcare provider can assess your baby’s risk of having these conditions.

Nuchal translucency ultrasound is typically performed between 11 and 14 weeks of pregnancy, which means it is an excellent early detection tool to help make informed decisions about your pregnancy, treatment plans, and your baby’s care.

It is important to note that the NT measurement and assessment of the nasal bone are only two of several factors that healthcare providers consider when assessing the risk of birth defects. Other factors, such as the mother’s age and medical history, may also be taken into account.

The benefit of the nuchal translucency ultrasound is that a great deal of information can be understood without an invasive tests such as amniocentesis. NT/nasal bone ultrasound is non-invasive and poses no risk to your developing baby. It is safe and relatively simple procedure that uses high-frequency sound waves to create images of your baby.

Ultimately, whether or not to have an NT ultrasound is a personal decision that should be made in consultation with your healthcare provider. They can help you understand the risks and benefits of the test and determine whether it is right for you and your baby.

How to prepare for your exam. Read More →


Common Questions

First Trimester NT/NB Screen is performed when the fetal crown-rump length (CRL) measures between 45 mm and 84 mm, which correlates to 11- and 14-weeks of gestation. If the CRL falls outside these measurements then the test is invalid. For that reason, we recommend that First Trimester NT/NB Screening be scheduled at 12- to 13-weeks gestational age whenever possible.

Yes. A detailed fetal assessment performed during the NT scan can detect 30 to 60% of all congenital abnormalities. Additionally, increased NT thickness is also associated with 40% of congenital heart defects.

A baby's sex can be determined as early as week 12. However, it is not as accurate until weeks 18-20 at your anatomy scan.

At 12 weeks, male and female fetuses have a bump called a genital tubercle. The bump represents the developing genitalia. During this stage of development, the genital tubercle points either toward the head, which means boy, or toward the feet, which means girl.

As much as we hope your little one will cooperate, they may have other plans. Crossed legs, the presence of the umbilical cord between the legs, or other less-than-ideal fetal positions can prevent the sonographer from getting a good look.

Girl Ultrasound
Boy Ultrasound