A biophysical profile (BPP) test is a common prenatal assessment used to evaluate fetal health during pregnancy. It provides important information about a baby’s well-being, especially when there are concerns or certain maternal conditions.
Understanding the BPP Test
The biophysical profile is a non-invasive diagnostic tool designed to assess fetal health in the womb. It combines ultrasound imaging with a non-stress test to create a comprehensive picture of the baby’s condition. The BPP evaluates how well the fetus is functioning, identifies potential issues, and helps determine if the baby is receiving enough oxygen and developing as expected.
Components and Procedure
A complete biophysical profile consists of five components: four assessed by ultrasound and one by an external fetal monitor. The ultrasound portion evaluates fetal breathing movements, gross body movements, fetal tone, and amniotic fluid volume. For example, fetal breathing movements are considered normal if at least one continuous breathing episode lasts for 30 seconds. Each of the other ultrasound components also has specific criteria for assessment.
The fifth component is the non-stress test (NST), which monitors the fetal heart rate in response to movement. During an NST, two sensors are placed on the mother’s abdomen: one tracks the baby’s heart rate, and the other monitors uterine contractions. This part of the test typically lasts 20 to 30 minutes. The entire BPP procedure usually takes 30 minutes to an hour.
When and Why a BPP is Performed
Healthcare providers often recommend a biophysical profile to monitor fetal well-being, especially in pregnancies with certain considerations. It is most commonly performed in the third trimester, typically after 28 to 32 weeks, though it can be done earlier if concerns arise.
Reasons for ordering a BPP include a pregnancy extending past the due date, or a report of decreased fetal movement. Maternal health conditions like diabetes, high blood pressure (hypertension), preeclampsia, or kidney disease also often lead to a BPP being performed. Additionally, the test may be suggested if the baby appears smaller than expected for its gestational age, if there is too much or too little amniotic fluid, or in cases of multiple pregnancies.
Interpreting BPP Scores and Next Steps
The results of a biophysical profile are presented as a score, totaling a maximum of 10 points. Each of the five components receives either 0 or 2 points, depending on whether the observed criteria are met. A score of 8 to 10 with normal amniotic fluid volume is generally considered reassuring, indicating a healthy fetus.
A score of 6 is often viewed as equivocal, suggesting a need for further evaluation, which might involve repeating the test within 12 to 24 hours. Scores of 4 or less are concerning and may indicate potential fetal distress. In such situations, healthcare providers might consider additional testing, increased monitoring, or even early delivery, depending on the gestational age and overall clinical picture. The interpretation of these scores guides decisions regarding continued pregnancy management or the timing of delivery.