Placental Function Assessment

If you are pregnant with one baby and having your First Trimester Screen through the Early Risk Assessment Program (NT ultrasound at EFW Radiology) - you will also have a placental function assessment.

Why screen for placental function?

Your placenta is a vital organ in pregnancy. It is the way that your baby receives oxygen and nutrients from your blood flow. Placental function assessment can identify if a placenta is functioning as expected based on certain blood values, your medical history, and ultrasound assessment of the blood flow to your uterus.

One of the conditions associated with a placenta that is not functioning as expected is preeclampsia. Preeclampsia is a condition that only occurs during pregnancy and sometimes postpartum. The main symptom of pre-eclampsia is high blood pressure. All pregnancies have a small chance of developing preeclampsia (around 1 in 20) regardless of the woman’s age, family history, or personal health. The exact cause of preeclampsia is not known. What we do know is that preeclampsia affects the ability of the placenta to provide oxygen and nutrients to the baby. The earlier preeclampsia develops, the greater the risk for both mom and baby.

What happens if a woman develops preeclampsia?

For most women, the first sign of developing preeclampsia is high blood pressure. From there, some women develop symptoms such as:

  • protein in their urine,

  • headaches,

  • upper belly pain (typically on the right side),

  • visual disturbances (such as spots or flashes).

The baby may be smaller than expected on ultrasound and some babies may need to be born prematurely. For more information on Preeclampsia visit the Preeclampsia Foundation.

Recent research has shown that firs trimester preeclampsia screening test is an accurate way to predict your risk of preeclampsia through placental function assessment. This screen, done at the same time as your first trimester screen (FTS) combines your medical and obstetric history (maternal risk factors) with your blood pressure, and certain other measurements at the time of your first trimester scan (11+0 to 13+6 weeks of pregnancy) to provide you with your personalized assessment.

How is placental function assessment done as part of FTS?

When you come in for your nuchal translucency ultrasound for your first trimester screen (FTS), you will be offered the opportunity to have placental function assessment done at the same time as your FTS.

There are four steps to this appointment: 

  1. A review of your health history with a nurse including your height and weight to determine if you have any risk factors that may affect the function of your placenta

  2. Analysis of your FTS blood sample - your blood sample will be tested for beta-Hcg, and PAPP-a (that you have had collected already for your first trimester screen - you do not need additional blood work done)

  3. Blood Pressure - measured in both arms two times to make sure the result is accurate 

  4. Ultrasound - measurements will be taken of your baby (including the nuchal translucency measurement) and the sonographer will also examine the blood flow through your uterine arteries

At the end of your appointment, all of this information is combined together to provide you with two screen results:

  • the chance that your baby could be affected by trisomy 21, trisomy 18 or trisomy 13

  • a personalized ‘low risk’ or ‘high risk’ for placental function

What does ‘low risk’ mean?

You will continue to receive your usual prenatal monitoring and care.

What does ‘high risk’ mean?

High risk means that there are findings in the screen that indicate you may be at risk of developing preterm preeclampsia (before 37 weeks of pregnancy) and should have closer monitoring. Your health care provider will discuss the option of taking aspirin (2 low dose aspirin every day at bedtime) to lower your chance of preeclampsia. This dose of aspirin has been shown to be effective in reducing the rate of preeclampsia. To get the best results, this treatment must be started before 16 weeks of pregnancy. This is why it is important to identify your risk of preeclampsia as early as possible in pregnancy.

*The use of aspirin to prevent preeclampsia should always be discussed with a health care professional.