Obstetrical Sonography II Lecture 21 The Biophysical Profile Holdorf Obstetrical Sonography II

Hypoxia Hypoxia is a condition in which the body or a region of the body is deprived of adequate oxygen supply at the tissue level. Hypoxia may be classified as either generalized, affecting the whole body, or local, affecting a region of the body.

Fetal Hypoxia Low levels of oxygen in the fetus, commonly as a result of diminished placental perfusion, utero- placental insufficiency, or compression of the umbilical cord. The condition is often accompanied by acidosis and is life-threatening unless prompt interventions are undertaken to restore well- oxygenated blood to the fetus. Signs of early fetal hypoxia include tachycardia and increased variability of the fetal heart rate; profound fetal hypoxia is characterized by bradycardia.

A biophysical profile is a prenatal ultrasound evaluation of fetal wellbeing, involving a scoring system. It is often done when the Nonstress test is non reactive or when there are other obstetrical indications. The biophysical profile (BPP) has 5 components: 4 ultrasound (US) assessments and a nonstress test (NST). The US assessments are: amniotic fluid volume, fetal tone, fetal activity, and fetal breathing movements. Each component is graded either 0 or 2 points, and then added up to yield a number between 0 and 10. A BPP of 8 to 10 is generally considered reassuring. A BPP normally is not performed before the second half of a pregnancy: fetal breathing movements do not occur in the first half.

A biophysical profile (BPP) test measures the health of the fetus during pregnancy. A BPP test may include a nonstress test with electronic fetal heart monitoring and a fetal ultrasound. The BPP measures the heart rate, muscle tone, movement, breathing, and the amount of amniotic fluid around the baby. A BPP is commonly done in the last trimester of pregnancy. If there is a chance that the fetus may have problems during the course of the pregnancy (high-risk pregnancy), a BPP may be done by 32 to 34 weeks or earlier. Some women with high-risk pregnancies may have a BPP test every week or twice a week in the third trimester.

A biophysical profile (BPP) test is done to check on the baby's health if the mother has the following: Hyperthyroidism Bleeding problems Lupus Chronic kidney disease Type 1 diabetes or gestational diabetes High blood pressure (hypertension) Preeclampsia A small amount of amniotic fluid (oligohydramnios) or too much amniotic fluid (polyhydramnios) A multiple pregnancy (such as twins or triplets)

Two specific indications for a BPP are Gestational Diabetes Pre-Eclampsia

Gestational Diabetes Gestational diabetes is a condition characterized by high blood sugar (glucose) levels that is first recognized during pregnancy. Usually, the mother's pancreas is able to produce more insulin to overcome the effect of certain pregnancy hormones on blood sugar levels. If, however, the pancreas cannot produce enough insulin, blood sugar levels will rise, resulting in gestational diabetes. During the second and third trimester, a mother's diabetes can lead to over-nutrition and excess growth of the baby. Having a large baby increases risks during labor and delivery.

Pre-eclampsia Pre-eclampsia is a multi system disorder characterized by high blood pressure and significant amounts of protein in the urine of a pregnant woman

Pre-eclampsia vs. eclampsia Preeclampsia is a condition that can develop during pregnancy characterized by high blood pressure (hypertension) and protein in the urine (proteinuria). If not properly recognized and managed, preeclampsia can progress to eclampsia, which involves the development of seizures in a woman with preeclampsia.

Usually a full bladder is needed for the test Usually a full bladder is needed for the test. Check to see if the patient smokes. If so, they should be asked to stop smoking for 2 hours before the external monitoring test because smoking decreases the baby's activity. A nonstress test with electronic fetal heart monitoring and a fetal ultrasound may be done at the same time as a biophysical profile.

The non-stress test (NST), is used to monitor a pregnant woman, typically in the third trimester. A cardiotocograph measures simultaneously both the fetal heart rate and the uterine contractions, if any, using two separate disc-shaped transducers laid against the woman's abdomen. An ultrasound transducer similar to a Doppler fetal monitor measures the fetal heartbeat. A pressure- sensitive transducer, called a tocodynamometer (toco), measures the strength and frequency of uterine contractions

Use of this machine during the third trimester to monitor fetal wellbeing is called a nonstress test. A positive (good) result is indicated by a reactive non-stress test. This means that the fetal heart rate increased (acceleration) by at least 15 beats per minute for at least 15 seconds at least twice during a 20 minute interval.

Use of this machine during labor is called a stress test Use of this machine during labor is called a stress test. When introduced, this practice was expected to reduce the incidence of fetal demise in labor and make for a reduction in cerebral palsy (CP). Its use became almost universal for hospital births in the U.S. In recent years there has been some controversy as to the utility of the cardiotocograph in low-risk pregnancies, and the related belief that over-reliance on the test has led to increased misdiagnoses of fetal distress and hence increased (and possibly unnecessary) cesarean deliveries. Biophysical profile is another test associated with this test. It is often done when the non stress test is non reactive.

External monitoring is done using two flat devices (sensors) held in place with elastic belts on the mother’s belly. One of these uses reflected sound waves (ultrasound) to keep track of the baby's heart rate; the other measures the duration of the mother’s contractions. The sensors are connected to a machine that records the information. The baby's heartbeat may be heard as a beeping sound or printed out on a chart. If the baby moves or the mother has a contraction, she will be asked to push a button on the machine. The baby's heart rate is recorded and compared to the record of movement or the contractions. This test usually lasts about 30 minutes.

Nonstress test

Results A biophysical profile (BPP) test measures the health of the fetus during pregnancy. The results are scores on five measurements in a 30-minute observation period. A score of 8 to 10 points means that the baby is healthy. A score of 6 to 8 points means that the mother may need to be retested in 12 to 24 hours. A score of 4 or less may mean the baby is having problems. Further testing will be recommended

Biophysical Profile Measurement/whatever it is… Normal (2 points) Abnormal (0 points)

Measurement: Nonstress test Normal is…(2 points) 2 or more heart rate increases of 15 beats per minute or more are seen with movement. Abnormal is…(0 points) Only 1 heart rate increase is seen or the heart rate does not increase by more than 15 beats with movement.

Breathing movement Normal is… 1 or more breathing movements last at least 60 seconds. Abnormal is… Breathing movement is less than 60 seconds or no breathing is seen.

Body movement Normal is… 3 or more movements of the arms, legs, or body. Abnormal is… Less than 3 movements of the arms, legs, or body.

Muscle tone Normal is… Arms and legs are usually flexed and the head rests on the chest. 1 or more extensions and return to flexion are seen, such as the opening and closing of a hand. Abnormal is… The fetus extends slowly and only returns partway to a normal position. The fetus extends but does not return to a normal position. The arms, legs, or spine are extended or a hand is open.

Amniotic fluid volume Normal is… At least one pocket of amniotic fluid of more than 1 cm is seen in the uterine cavity. Abnormal is… Not enough amniotic fluid is seen in the uterine cavity.

What Affects the Test? Reasons the test cannot be performed or why the results may not be helpful include: The baby is in a position that makes an ultrasound difficult. The mother is unable to lie still throughout the procedure. Extremely overweight mother, which may make it difficult to correctly position the external monitoring device.

An infection in either the mother or the baby. Low (hypoglycemia) or high (hyperglycemia) blood sugar levels. Medicine, such as magnesium sulfate. Steroids given to help the baby's lungs mature. Alcohol or illegal drugs, such as cocaine. In rare cases, stool (feces) or air in the intestines or rectum interfering with the fetal ultrasound.

A biophysical profile may be done after an injury, such as a car crash or fall. Research is being done on the usefulness of BPP testing during labor. Low BPP test scores may help predict the need for a cesarean section or whether a baby will need specialty care after delivery.