Fetal Biophysical Profile Testing

A fetal biophysical profile is a new type of health assessment test that can be used to evaluate the health and development status of a fetus in the womb. A fetal biophysical utilizes a combination of ultrasound imaging and electronic fetal heart monitoring (EFM) to measure the baby’s breathing, heart rate, muscle development, and amniotic fluid levels in the womb. The results of the EFM and ultrasound are then scored based on certain criteria.

Fetal biophysical profiles are commonly done in pregnancies that are considered “high-risk” for complications and/or pregnancy loss. The biophysical testing can be done at any time after the 25th week of gestation, but the results are more meaningful when done after about the 31st week.

Low scores on a fetal biophysical profile can help doctors diagnose potentially dangerous pregnancy complications in advance. Early diagnosis of obstetric complications and conditions is absolutely critical to effective neonatal care and avoiding birth injuries. Learn more below about the benefits of fetal biophysical profiles.

Why are Fetal Biophysical Profiles Done?

Fetal biophysical profiles are done to identify and diagnose potential problems and complications that can disrupt or restrict the supply of oxygen to the baby. Diagnosing these issues in advance gives doctors the opportunity to intervene and deliver the baby earlier or take other preventative measures to avoid permanent injury.

Your doctor might want a fetal biophysical done if you have a high-risk pregnancy because of the increased risk of complications arising. High-risk pregnancies and other situations that might warrant a biophysical profile include:

  • Advanced maternal age (over 35)
  • Twins / multiples
  • Maternal medical conditions such as diabetes, heart disease, or hypertension
  • Post-term pregnancy (2 weeks past due date)
  • History of obstetric complications in prior pregnancies
  • Low amniotic fluid (oligohydramnios) or too much amniotic fluid (polyhydramnios)
  • Maternal obesity
  • Abnormal fetal movements and/or developmental concerns

When high-risk pregnancy conditions are present, fetal biophysical profiles might be done once a week until delivery or on a regular schedule.

What are the Risks of a Fetal Biophysical Profile?

Fetal biophysical profiles are entirely noninvasive procedures so there are no direct health risks to mother or baby. The only potential risk is that performing the test may cause increased stress levels for the mother, which can have a secondary negative impact. Another possible problem with biophysical profiles is that they sometimes result in “false positives” and result in unnecessary treatments.

What to Expect During a Fetal Biophysical Profile Test?

Testing procedures for a fetal biophysical profile are not that much different than the normal prenatal testing that most pregnant women get very used to after a few doctor visits. The first part of the biophysical involves the use of electronic fetal monitoring devices. These usually involve some type of belt with sensors that get strapped around the abdomen to record the baby’s heart rate patterns. The belt is hooked up to a machine that records the heart rate and other information.

The next part of the biophysical profile is an ultrasound exam. The ultrasound procedure for a fetal biophysical is the same as it is for regular ultrasounds. The technician or doctor applies some jelly to the abdominal area and gently rolls an ultrasound transducer over the skin to generate images on a computer display.

The ultrasound imaging results and the results of the non-stress testing with the electronic fetal monitoring are then analyzed and scored based on certain medical criteria. That score is used to determine whether the baby is under stress or if complications have arisen.

Scoring for Fetal Biophysical Profiles

A fetal biophysical profile test evaluates 5 separate areas of fetal health measurement. Each of the 5 categories is given a score between 0 and 2 points based on very specific medical criteria:

  1. Fetal Heart Rate (Nonstress): the baby’s heart rate patterns are examined and given a score based on whether they are reactive or non-reactive. If the baby’s heart rate displays 2 or more accelerations within a 20-minute period it is classified as “reactive” and gets a score of 2 points. No accelerations is considered “non-reactive” and gets a score of 0.
  2. Fetal Breathing Pattern: at least one 30 second episode of rhythmic breathing will earn a score of 2 points. No rhythmic breathing lasting at least 30 seconds will result in a score of 0.
  3. Fetal Movement: a score of 0 or 2 will be given based on how much movement the baby displays during the testing. 3 or move limb or body movements within a 30 second period will earn a score of 2.
  4. Fetal Muscle Tone: fetal muscle tone is assessed by looking to see if the baby can move its limbs from a bent to a straight position.
  5. Amniotic Fluid Level: this assessment point looks at the size of amniotic fluid pockets visible on the ultrasound imaging. The largest visible fluid pocket must meet certain size criteria to get a score of 2.

Each of the scores from these 5 assessment categories is added together to get a total, cumulative score for the fetal biophysical profile. A score of 8 or higher is considered good and a sign of fetal health. A score of 6 may be considered inconclusive and the doctor may want to retest in 24 hours. Scores of 4 or lower are cause for concern and might prompt additional testing, or emergency delivery (depending on how far along the pregnancy is).

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