00:01 Now, we will discuss Antenatal Testing. 00:06 So the purpose of antenatal testing is to ensure fetal well-being. 00:10 And when we say, reassure us or ensure fetal well-being, we mean that there are no signs of fetal asphyxia. 00:18 So let's first talk about the non-stress test. 00:22 So the non-stress test is performed by doing the external fetal monitoring to look at the fetal heart rate. 00:29 We then determine if the fetal heart rate is reactive, which means fetal well-being is reassured, or is it non-reactive, meaning there's additional testing needed to be done to assure fetal well-being. 00:42 Reactive. And this is very important means that there is two accelerations of greater than 15 beats per minute, lasting at least 15 seconds over a 20 minute time period. 00:53 So again, you're looking at a 20 minute time period on the external fetal monitor, and you're looking to find two accelerations of greater than 15 beats per minute, each lasting for at least 15 seconds. 01:06 So the next type of antenal testing is the biophysical profile. 01:11 Now with the biophysical profile, you're looking at five different categories expecting to see certain things in this category. 01:19 Patients are given a two if the fetus performs the maneuvers that we're looking for, and a zero if they do not perform the maneuvers. 01:28 Again, you have 30 minutes to observe it. 01:30 So we're looking at fetal movement. 01:33 We're looking at fetal tone, fetal breathing, the amniotic fluid, and again, the non-stress test. 01:40 So with the fetal movement, we're looking to see three gross movements within that 30 minute time period. 01:47 Fetal tone is looking for fine movements, like the hands moving the fingers opening and closing the palm. 01:53 Fetal breathing, we're looking for sustained breathing for 30 seconds over that 30 minute time period. 01:59 Amniotic fluid volume, really, we're just looking at the maximum vertical pocket and we want that to be at least two centimeters. 02:06 And then we've already discussed the non-stress test. 02:10 So if we have a score of eight, that is reassuring. 02:12 That means that that fetus is doing well and there's no signs of fetal asphyxia. 02:17 If there's a score of six, this is considered equivocal. 02:21 So it doesn't mean that we are reassured but it also doesn't mean that the baby is concerning for asphyxia. 02:27 However, if the patient is term, meaning 37-weeks, that means we need to deliver that fetus. 02:34 At a score of four, it is a little bit concerned this for asphyxia and we do need to deliver at that point. 02:41 So the biophysical profile can be used when the non-stress test is not reactive as a confirmation that the baby is doing okay. 02:51 So the next antenatal testing that we use is a contraction stress test. 02:56 So with the contraction stress test, we induce contractions, and that can either be through nipple stimulation, or it can be induced by given pitocin. 03:05 And we're looking to see that a patient has contractions over a 10-minute timeframe. 03:11 Now, this test, we do not want to be positive. 03:14 So it's a little different than the non-stress test. 03:17 If the test is positive, that means that more than 50% of the contractions are associated with a late deceleration. 03:25 The test is equivocal when there's intimate late decelerations but less than 50%. 03:31 And the test is negative when there's less than 50% of the contractions associated with late decelerations. 03:37 Again, for the contraction stress test, we want a negative result to reassure us that the fetus can tolerate labor. 03:45 Pay attention to this slide because this is high yield. 03:50 And then the final test is the Umbilical artery doppler. 03:53 Now this is a test is performed by doing an ultrasound looking at the doppler of the umbilical artery. 04:00 And we do this when we are suspected in fetal growth restriction. 04:04 Now our results can show a normal S/D Systolic/diastolic ratio or it can show absent or even worse it can show reversal flow. 04:14 If it is, if there were flow is absent or reversal then that indicates that there is an increased resistance in the placenta. 04:23 So let's look at a question. 04:25 A 27-year-old gravida 1 para 0 female at 28 weeks and 3 days of gestation with a history of chronic hypertension presents for an antenatal visit. 04:35 She has had no issues this pregnancy. 04:38 All antenatal testing has been within normal limits. 04:41 She takes labetalol for her chronic hypertension. 04:44 On physical exam, her blood pressure is 140/95. 04:47 The fetal heart rate is 150 beats per minute, And the fundal height for the mom is 23 centimeters. 04:56 Now when we think about that, 23 centimeters at 28 weeks gestation that sounds a little small to me. 05:04 So the next best step in her management is... 05:07 A. A fetal ultrasound. 05:09 B. Fetal doppler of the umbilical artery. 05:11 C. Contractions stress test. 05:13 or D. Biophysical profile. 05:17 So in this case, we first want to do a fetal ultrasound. 05:20 Now, there's lots of reasons why the fundal height may be small. 05:23 It could be because there's decreased amniotic fluid. 05:26 It could be because the baby is small, or it could be our measurements are not that great. 05:30 So we want to confirm that the measurement is small first by fetal ultrasound. 05:34 If the fetus is indeed small, then the fetus will warrant a fetal Doppler of the umbilical artery. 05:40 But the next best step in her management is to perform the fetal ultrasound.
The lecture Antenatal Testing by Veronica Gillispie, MD, FACOG is from the course Antenatal Care. It contains the following chapters:
Which of the following non-stress test strips is reassuring?
Which of the following is NOT part of a full biophysical profile?
A 24-year-old G1P0 at 38 weeks gestational age presents to the ward for concern over decreased fetal movement for the past 10 hours. A biophysical profile is performed. After 30 minutes of ultrasound observation, the physician notes the following: a single deepest pocket of amniotic fluid measuring 5.3 cm, 1 episode of fetal breathing lasting 60 seconds, extension and flexion of the fetal arm once, and 2 discrete body movements. The non-stress test is reactive. What is her biophysical profile score and what should the next step be?
Which of the following defines a POSITIVE contraction stress test?
What defines "fetal well being"?
A 35-year-old G4P3 female at 32 weeks and 2 days with a history of chronic smoking is seen in the clinic. Her blood pressure and heart rate are normal, her urine dip is negative for protein and glucose, and she feels regular fetal movements. Her fundal height is 27 cm. You are worried about fetal growth restriction so you do a fetal ultrasound and confirm that the fetus is measuring small for her gestational age. What is the best management?
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Good lecture that covers the antenatal tests with appropriate detail. Would have liked to have the context of what weeks gestation these tests occur - 32 and 36-38 weeks gestation per article.