Basic Obstetric POCUS

Chapter 8. Second-Third Trimester and Fetal Presentation

Welcome to the section on the overview of the second trimester ultrasound. Performing an ultrasound in the first trimester is ideal for assessing pregnancy viability and measurements for determining gestational age and estimating a due date.

Nevertheless, there are situations in which women are unable to obtain care before the second trimester. In such cases, it is essential to have a comprehensive evaluation of the pregnancy, assessing not only gestational age but also additional indicators of maternal and fetal health.

This section offers a brief overview of the mid-trimester ultrasound appropriate for point-of-care. It does not cover detailed fetal anatomic surveys (which is part of a standard mid-pregnancy ultrasound) but does demonstrate typically observed features.

By the completion of this Section the participant will be able to:

List the components of a second trimester general evaluation
Describe typical reasons for a second trimester ultrasound in a triage situation for obstetric complications
Accurately describe placental locations on images
Describe briefly the components of obtaining fetal biometry
Recognize the components of a fetal anatomic survey to adequately interpret these fidings on outside reports

Point-of-care ultrasounds performed in the second trimester can provide a great deal of information. A 20-week fetal anatomic survey is typically conducted at this stage, which can detect most abnormalities. If this survey is not accessible, or if a woman has not received prior prenatal care or ultrasound, it may be necessary to assess fetal growth. This type of POCUS is not included in this current course for the midwives in your group. If a woman’s size is seems to be discrepant with her gestational age, she should be refered for standard ultrasound assessment for fetal growth.

Non-routine second trimester ultrasound is typically used to assess vaginal bleeding (often for placental location or cervical competency), determine fetal number and presentation, and evaluate fetal growth through biometry when necessary.

Any of these are reasons to consult or collaborate with an advanced practitioner, making the second or third trimester a valuable triage tool.

PLEASE NOTE THAT POCUS EVALUATION DOES NOT INCLUDE A COMPLETE FETAL ANATOMIC SURVEY

Point of care ultrasound indications

Figure 1 presents the primary reasons for performing a mid-pregnancy POCUS exam.

Figure 1. Point-of-care ob ultrasound indications

Additional reasons include assessing fetal growth, well-being, and identification of gross abnormality. since some of these may be missed during an earlier scan.

Figure 2. Additional indications for OB POCUS ultrasound in mid pregnancy

Two main areas are studied: the FETUS, and the MATERNAL/FETAL environment, which includes the uterus, fluid, cervix, placenta, and cord.

Figure 3. Two components for POCUS exam in second-third trimester

Second-third trimester scans also help assess patients with complications for triage in hospitals or clinic settings. Some indications for this triage ultrasound include decreased fetal movement, lagging fundal growth, vaginal bleeding, and signs of preterm labor in women.

One important purpose is to rule out pre-term labor. Typically, assessment of preterm labor involves monitoring for contractions; however, it can also be important to evaluate cervical length for shortening. Cervical measurement will be addressed in more detail in a subsequent chapter in this course.

Although fetal anatomic survey is NOT part of a point-of-care ultrasound assessment under current national and international guidelines, certain parts of fetal anatomy are described in this course. These anatomic landmarks are used to find correct imaging planes for biometric measurements. There will be an adjunctive chapter at the end of this course to describe one or more biometric measures that you may practice.

When performing a second trimester scan, these are areas that a provider should evaluate:

Fetal number, viability, position
Cervix
Placenta and cord locations, and proximity to the cervix
Amniotic fluid – general assessment

Figure 4. Components of Second Trimester POCUS

Other questions to be answered:

--Does the baby have adequate movement and heartrate?

--Are there any grossly obvious anatomic variations (fetal or maternal) that require consultation or referral?

--Are the baby’s growth measurements appropriate?

Basic fetal biometry

Basic fetal biometry is used to confirm gestational age as well as determine adequate fetal growth when measurements are compared to standards. The following are the 4 primary measurements obtained in a biometry POCUS. Fetal weight is then determined by the computer based on the composite of these measurements.

BPD – Biparietal Diameter
HC – Head Circumference
AC - Abdominal Circumference
FL - Femur Length

EFW - Estimated fetal weight (Calculated from the above measurements)

For a second-third trimester ultrasound, use a transabdominal transducer (with lower frequency) to penetrate deeper into the abdomen and pelvis.

A curvilinear transducer is the appropriate first choice of transabdominal transducer.

When trying to view the cervix or other deep pelvic structures, using the transvaginal transducer is the preferred method Since you will not be using transvaginal ultrasound, it is possible to get an estimate of cervical length following certain guidelines. if you determine that a cervix might be shortened, you must refer the woman to a sonographer who can perform that exam to verify cervical length.

Figure 5. Image of a transabdominal ultrasound in second trimester

This image shows a transabdominal scan of the pelvis with a full bladder (dark area on the right of the image). Anatomical structures are easily seen in this woman. As the fetus develops, visibility of these structures improves.

First step: Fetal Viability

Start by scanning the whole uterus in both sagittal (longitudinal) and transverse planes to identify all fetal and maternal structures, as well as fetal position. There will be a chapter at the end describing techniques on how to perform the exam.

VIDEO CLIP 1. Finding the fetal heartbeat

Assessing fetal viability is an initial step. The video clip above shows fetal cardiac activity. To play the clip, move the cursor to the lower part of the slide and click the arrow. When starting a scan, confirm either the presence of fetal movement or cardiac motion before moving on to examine other structures. Capturing an M-mode image is recommended to document heart rate.

Video clip 2. Positioning the M-mode line to transect the moving heart structures (the M-mode line is the vertical yellow line in the image)

Cervical Length

During POCUS exam in second or third trimester, it is generally advisable for the bladder to be partially empty. This can reduce discomfort during scanning and helps ensure that pelvic structures are not distorted or displaced by a full bladder. A transvaginal transducer provides the most accurate measurement, but a general assessment can be done without one.

Normal cervical length in pregnancy is 3–3.5 cm. Lengths under 2–2.5 cm are considered shortened and require advanced assessment. Individuals with this finding should be referred for further advanced evaluation

If a transvaginal probe is unavailable, and a cervix appears shortened on transabdominal scan, refer the patient for a diagnostic ultrasound.

Ensure that the woman’s bladder is not full when assessing the cervix, as this may affect cervical length. A full bladder can falsely stretch and elongate a cervix, making it appear longer than it is.

Cervical length variations by gestational age will be covered in detail in the chapter on Maternal Fetal Structures in this course.

Figure 6. Cervical length using transabdominal transducer

In Figure 7 (below), you can see that the very full bladder in the left image has distorted/elongated the cervix to a measurement that is likely not correct - 4.76 cm. When the bladder is emptied (right image), the cervix assumes a shorter length (3.19 cm).

One of the difficulties of measuring a cervix transabdominally is that a full bladder helps us to visualize the cervix better, since it provides an ‘acoustic window’ for us to see through. The empty bladder does not give us that advantage, so it makes it a bit more difficult to visualize the cervix well.

Figure 7. Cervical length with FULL bladder compared to emptied bladder

Use of a transvaginal probe allows the ultrasound to be right against the cervix to provide us a detailed view for more accurate measurement (Figure 8). This figure is here just to demonstrate the difference in the image quality.

Figure 8. Cervical length using a transvaginal transducer

Cervical changes

Once a cervix begins to shorten, the next thing to happen is opening of the cervix at the internal os. This is known as ‘funneling’.

Funneling refers to the V-shaped opening of the internal os that occurs when pressure is exerted on this area of the cervix, typically from uterine contraction. This is shown in Figure 9 (below) in the image on the right. It is particularly concerning in the presence of increased uterine contraction frequency and intensity, a history of preterm labor or birth, or when the functional (intact) cervical length is reduced to less than 2.5 cm. Cervical measurements and the clinical implications of are addressed in more detail in the chapter on maternal-fetal structures.

Figure 9. Example of cervical funneling

Placental location

Following the first trimester, the general location of the placenta is an important assessment, as well as measuring the proximity to the internal os. An anterior placenta is situated along the anterior wall of the uterus (appearing toward the top of the ultrasound screen). A fundal placenta typically appears at the uterine fundus, as visualized in a sagittal plane. Conversely, a posterior placenta is positioned on the posterior uterine wall, adjacent to the maternal spine. These are demonstrated in Figure 10 (below).

Figure 10. Placenta locations

Examination of the entire placenta includes assessing the lower edge and its distance from the internal cervical os. A placental edge located less than 2 cm from the internal os is defined as low-lying. Further discussion of low-lying placenta and placenta previa is provided in the chapter on Placenta, later in this course.

Figure 11. Images of placenta vascularity and cord insertion site (left image)

If color doppler is available, identifying where the cord inserts into the placenta can be helpful. If it inserts centrally, that is normal. If it inserts toward the outer margin of the placenta, this could have implications for fetal growth later in the pregnancy.

Assessing bleeding

When a woman presents with bleeding, two primary scenarios can be evaluated via ultrasound. If the placenta detaches or separates from the uterine wall, there may be either active bleeding or no observable hemorrhage. In cases where abdominal pain and uterine rigidity are present, placental abruption should be suspected. This condition constitutes a medical emergency. While some patients may experience a “chronic”, or a “small” abruption and continue to full term, a complete placental abruption requires immediate intervention.

Figure 12. Image of placental abruption

If a total abruption is suspected, immediate assistance should be sought without delay for an ultrasound. Detecting evidence of an abruption can be challenging, even for experienced sonographers, so urgent management should be based on clinical findings instead.

More information on placental abruption is presented in the chapter on maternal-fetal structures.

Figure 13. Placental texture

Placental scans check for size and characteristics, mainly by detecting early calcifications and indentations. Grading of placentas is now considered clinically relevant only if these signs appear before the third trimester, which may occur in cases of uncontrolled gestational diabetes and fetal macrosomia. Once again, this is reviewed in greater detail in the maternal-fetal structures chapter.

Cord

The umbilical cord can be examined in both longitudinal and transverse (cross-sectional) views. In the longitudinal view, twisting of the cord may be observed, which is commonly associated with fetal movement, an assurance of overall fetal well-being. This is generally considered a typical finding. In the cross-sectional view, one larger vessel (the umbilical vein) and two smaller vessels (the umbilical arteries) are usually present. If only two vessels are identified, this can sometimes be linked to certain fetal complications, so further consultation with a specialized provider is recommended if this observation is made.

Figure 14. Umbilical cord characteristics

Amniotic fluid

Amniotic fluid levels can be generally assessed by how clearly fetal structures appear during scanning. Low fluid results in cloudier, lower-resolution images, as adequate fluid level improve image clarity.

Figure 15. Images demonstrating poor image quality indicating low fluid

Alternatively, when all fetal images are distinctly visualized and the fetus appears to be surrounded by an excessive amount of amniotic fluid, this may suggest polyhydramnios. Assessment of amniotic fluid volume will be addressed in the chapter on Biophysical Profile in this course. It is most predictive if evaluated after 32 weeks’ gestation but can be performed as early as 28-29 weeks’ gestation.

Figure 16. Image demonstrating clearer image due to greater amount of amniotic fluid

Polyhydramnios (excessive amounts of fluid) in the second trimester often signals a fetal abnormality. Consultation or referral for advanced assessment is recommended. Excess fluid may suggest a chromosomal disorder, syndrome, or a fetal swallowing issue such as esophageal atresia. Polyhydramnios is more common in third trimester and may or may not be associated with a fetal complication.

Figure 17. Excessive levels of amniotic fluid (polyhydramnios)

BIOMETRY

Biometry is an important tool used to determine gestational age and measure growth patterns.

Figure 18 provides a list of the key steps. First trimester ultrasounds are most reliable for due dates, but second trimester scans are suitable if early data is unavailable. This chart provides an overview; each component will be covered in a separate course.

Figure 18. Components of biometry

The next few figures show how each of these parameters is measured so that you will be familiar with how this is done.

Head measurements

Two measurements of the head involve measuring the distance between each biparietal bone, as well as the overall head circumference.

Figure 19. BPD and Head Circumference

Fetal abdomen measurement

Figure 20. Abdominal circumference

The abdominal circumference must be measured when the fetal abdominal structures of the stomach, spine, and portal vein are all aligned, as shown in Figure 20

Femur length

Femur length is measured as shown in the image on the right in Figure 21.

Figure 21. Femur length

Fetal extremities

Although fetal extremities are not measured, it is very important to observe and document; ; both hands and arms, and both legs and feet should be identified.

Figure 22. Fetal extremities

Fetal sex

Many women and their families want to find out the baby’s sex when you are doing a scan. It is perfectly fine to look for this. Although it seems to have a non-medical or social purpose, there are times when it is important to determine certain genetic risk factors.

Keep in mind that you must tell the woman there may be error in your assessment, especially if done before 20 weeks gestation. Some countries have regulations that allow only sonographers or physicians to tell a woman her baby’s sex.

Figure 23. Fetal sex identification

Fetal anatomic survey

The components of a full fetal anatomic survey is presented here for information only.

The overview in Figure 24 outlines the basic fetal anatomic survey components. Note that these tasks will not be reviewed in this course or series. However, recognizing the components of a standard mid-trimester fetal anatomy survey and understanding the purpose of each component is important when reviewing and interpreting findings of an outside report.

Figure 24. Components of a fetal anatomic survey

FETAL PRESENTATION AND POSITION

This section describes fetal presentation and position. While prenatal care providers commonly use Leopold’s maneuvers for assessment, ultrasound provides more accurate details, such as fetal alignment and presentation. Learning ultrasound helps guide decisions for supporting mothers before and during labor.

Knowing fetal position and presentation can determine clinical decision-making close to delivery and impact labor management.

This section covers various fetal positions and their appearance on a 3D diagram to help with interpreting images.

OBJECTIVES:

By the completion of this Section the participant will be able to:

1. Use maternal and fetal anatomic landmarks to determine fetal position and presentation

2. Correctly capture and annotate fetal presentation at term

3. Describe the presentations that are not deliverable vaginally

Major fetal presentations

For many providers, this is a review of fetal presentations and positions. It is crucial to know which positions can affect labor management and which require referral and Cesarean section delivery.

"Presentation" refers to the part of the fetus entering the pelvis (e.g., head or breech), while "position" describes the baby's orientation relative to the mother's anatomy. Although these terms are often used interchangeably, using "position" to mean "presentation" is not incorrect.

Figure 25. Major fetal presentations

Not only is presentation important, but the actual position of the presenting part can influence labor management. Figure 26 illustrates various cephalic positioning.

Figure 26. Variations of cephalic/vertex positions

Babies in cephalic or vertex presentation can be positioned in various ways, defined by where the occiput is directed in relation to the mother's pelvis. For instance, ROP indicates the occiput is toward the mother's right side and sacrum.

In addition, even if a baby is head down, if the head is extended abnormally, this can impede labor progress and cause dystocia (Figure 27 below). It also may necessitate operative delivery.

Figure 27. Variations of cephalic position based on head flexion/extension

During labor, the baby's head may flex or extend. Ideally, the head is flexed as it descends into the pelvis, which its structure encourages. However, some babies remain in a neutral (sinciput) position or extend backward, resulting in brow or face presentation.

When evaluating the diameter of the head in these positions, it is noted that brow presentation results in a diameter that cannot pass through the pelvis. A persistent brow presentation during labor is not suitable for vaginal delivery. In contrast, a sinciput presentation might result in vaginal delivery because the degree of extension is less pronounced, and labor forces can promote flexion as the head moves through the pelvis. Face presentation may allow for vaginal delivery if the chin is positioned anteriorly, as this orientation shares the same longitudinal diameter as vertex presentation.

Figure 28. Face or chin pres

When performing Leopold’s maneuvers on a woman, a depression above the symphysis pubis may indicate a malpresentation. This could be an initial clue for identifying a woman at risk for a protracted labor course.

Risk factors for malpresentation are:

Grand multiparity
Advanced maternal age
Pelvic masses
Multiple gestation
Polyhydramnios
Macrosomia
Congenital malformations

As seen in Figure 29, a vaginal delivery is possible if the head is encouraged to flex as it moves into and through the pelvis.

Figure 29. Illustrations of face and chin presentation - mentum anterior

However, if the chin is facing posteriorly, toward the mother’s sacrum, it is NOT possible for the baby to be delivered vaginally. If this is the case, immediate consultation and referral are indicated for a cesarian section delivery

Figure 30. Illustration of mentum posterior position

Breech variations

here are also variations in breech positions. Complete breech means that there are feet and buttocks presenting together. Frank breech means that only fetal buttocks present. An incomplete or footling breech presents the greatest risk of complicated birth due to both cord and limb entanglement, as well as incomplete dilation of the cervix up to the point of the head coming through it. You may be required to manage or deliver babies in these situations, but these could portend a complicated birth and assistance is required. If there is time and availability, consultation and referral are indicated.

Figure 31. Breech position variations

USING ULTRASOUND TO ASSESS FETAL PRESENTATION AND POSITION

The following section of this chapter illustrates how to identify the fetal position with POCUS, using ultrasound images and 3D diagrams.

"Fetal lie" refers to the alignment of the fetus's axis with the mother's. Terms like vertex and breech describe this relationship based on how the baby's body is positioned relative to the mother's torso.

FIgure 32. Assessing presentation and position with ultrasound

Mentally visualizing the baby's position in utero aids scanning. Perrforming Leopold’s maneuvers before third-trimester scans often helps expedite the scanning process.

When scanning, you should observe the following principles:

· The left side of the screen corresponds to the direction of either the mother's head or right side.

· The top of the screen represents the mother's skin surface, while the bottom corresponds to her spine.

In Figure 32, the “profile” view of the baby’s face is directed “upward”, it means that the baby is looking up toward the mother’s abdominal surface (or toward the probe).

The image below (Figure 33) presents a cross-sectional or transverse view of the fetal heart, indicating that the ultrasound beam transected the fetus in a transverse direction. The view does not provide information regarding whether the fetus is in a vertex, breech, or transverse position, as it does not depict its relationship to the maternal anatomy.

Figure 33 Transverse image of baby (ultrasound beam is transecting the fetal chest)

In the image below (Figure 34), the baby is “face up”, but look at its torso’s relationship to the mother’s pelvis. This baby is in a transverse lie. The ultrasound image on the right might appear that the baby is vertex, but keep in mind that the ‘green dot’ can either indicate direction of the mother’s head, or her right. In this case, the green dot indicates this is the direction of the mother’s right side, and therefore the baby’s head is toward her left side (as shown in the 3D image).

Figure 34. Image of baby in transverse lie

Figure 35. Image of baby in vertex presentation, occiput toward maternal right, face toward maternal left

In the image above (Figure 35), the baby’s spine is positioned toward the mother’s right side. It is not upward toward the mother’s skin, nor is it truly aligned with the mother’s spine. The head is toward the cervix (away from the mother’s head) assuming this is a sagittal view.

Figure 36. Image of baby in transverse lie

Thw baby in Figure 36 is in a transverse lie, meaning the fetus lies sideways across the lower maternal abdomen. The transducer is positioned sagittaly on the mother's abdomen, with the green dot showing the notch toward the maternal head; thus, the baby's head is toward the maternal left. The image on the screen is the beam transecting the fetal abdomen transversely.

The fetus is in a breech position, with the head located near the uterine fundus. The fetal spine aligns with the mother's spine, resulting in the fetus facing upward toward the maternal abdominal wall.

Figure 37. Image of breech breech position, sacrum posterior (toward mother’s spine)

Figure 38 is another breech presentation. You can see the lower fetal spine extending downward toward the cervix. Since we are seeing the fetal spine, that indicates that the baby is sacrum posterior (meaning sacrum is toward the mother’s spine).

Figure 38. Image of sagittal view of mother, breech presentation

Figure 39 shows what the baby looks like for this same image from the previous slide.

Figure 39. Same image as Figure 38, with 3D illustration

The image below in Figure 40 is of a baby in a footling breech lie, with both feet on the cervix and bladder.

Figure 40. Image of footling breech

Figure 41. Same image as Figure 40, with 3D illustration

Figure 42. Image of extended fetal legs

Without knowing whether the image above (Figure 42) was taken transverse or sagittally, we cannot determine baby’s true position. However, just looking at the view of the uterus, a cervix cannot be clearly identified, so it is most likely a transverse view. Since this is the case, the baby is laying along that same axis and the legs are extended toward the maternal left side. So this baby is in a transverse lie with the head toward the maternal right, and feet pushing toward the left of the uterus.

Figure 43. Same image as Figure 42 with 3D illustration

The term baby in the image of Figure 44 confirms fetal presentation, accurately annotates the maternal bladder, and clearly shows the baby is in the vertex position.

Figure 44. Image and illustration of baby in ROT (right occiput transverse) position

The image below (Figure 45) demonstrates that with annotation you can discern the presenting part. Without annotation, it would be difficult to say what this image represents.

Figure 45. Image of single footling breech

The image in Figure 46 was taken to determine fetal presentation at term. It is labeled correctly with annotation. The fetal part doesn’t exactly look like a head – there is no skull or calvarium seen. However, identifying the fetal part might be questionable if there were no annotations.

Figure 46. Image with fetal buttock near maternal bladder, well-annotated

Figure 47. Image of breech presentation, sacrum anterior

Figure 48 shows a profile view of the baby’s face, demonstrating that it is directed upward (baby is looking up toward the transducer). When you see a profile view of a baby’s face, that means that the occiput is posterior.

Figure 48. Image of face profile with fist near mouth

Figure 49. Same image of occipute posterior and facial profile, illustrated with 3D

In the image below (Figure 50), there is no question of what is presenting based on the annotations.

Figure 50. Image of fetal bladder in breech with good annotation

Below (Figure 51) is another 3D rendering of a baby that is breech, with the buttocks in SA (sacrum anterior) position. In the ultrasound image we do not see the fetal buttocks since the ultrasound beam is angled toward the fetal upper spine and head. But because we know the orientation of how the baby is laying (head toward the uterine fundus), we know it is breech.

Figure 51. Baby in breech presentation with curved spine anterior

This baby below (Figure 52) appears to be laying straight face up toward the front of the mother, in a vertex presentation.

Figure 52. Image of baby in OP (occiput posterior) position, showing face profile

Identifying fetal orbits is very helpful in labor management, in particular. We know the baby in Figure 53 is cephalic or vertex, but the 2 images show fetal orbits facing upward. This typically indicates an OP position, but can represent head extension. So it is prudent to evaluate further for potential sinciput, brow, or face presentation if in labor.

Figure 53. Images of fetal orbits facing anteriorly (indicating OP position)

Figure 54. Same images as in Figure 53, with 3D diagram

Figure 54 shows the angle used to scan the head for viewing the orbits. The face is oriented anteriorly, although it is positioned at a different angle compared to the fetal face profile.

The image below (Figure 55) shows the baby’s face toward the mother’s right side. It is common to see a “full face” view like this when a baby’s head is in an occiput transverse position in the pelvis. Although it looks to us that baby is looking at us, the baby’s head is actually facing to the side of the mother. This would be normal before labor, but during labor this could represent a persistent OT (occiput transverse) presentation

Figure 55. Image of baby in vertex with beam transection anterior face, creating a “facial” view of the baby

Figure 56. What’s incorrect about this image?

Look carefully at the image in Figure 56 and try to see what is wrong. By looking closely, it is easy to recognize that the transducer is backward. The maternal bladder should be on the right side of the screen, and the green dot is on the right side of the screen instead of the left. This is another example of how important orientation is to correct assessment.

Figure 57 below shows that the baby’s sacrum is directed toward the mother’s front. The transducer is only transecting the lower part of the baby so this is all we see on the image. However, we can assume that the baby is vertex by looking at this image.

Figure 57. Vertex presentation, beam transecting anterior fetal spine and sacrum sagittaly

Figure 58. Image of breech with anterior spine

In Figure 58 all we can see is the back of the neck and the thoracic spine. But we can presume that this baby is in a sagittal lie with the head toward the mother’s head, and therefore in a breech presentation.

Figure 59. Image of vertex presentation, straight OP position

The image above (Figure 59) is of a baby that is straight OP (occiput posterior). If this woman is in labor, you would want to encourage position changes to help rotate the back of the baby’s head and spine anteriorly.

The image below (Figure 60) is of a baby whose spine is straight anterior and has normal thoracic curvature. We can tell this baby is vertex since the ultrasound image shows the back of the baby’s neck (cervical spine) toward the right of the screen. As babies get bigger, it is difficult to capture the entire spine in a single view. But the 3D rendering shows what the baby would look like in this view.

Figure 60. View of anterior spine and thoracic curvature

The image in Figure 61 is a demonstration of how babies can twist and turn in utero. This is not an abnormally twisted spine!

Figure 61. Baby twisting its torso (twisted spine)

SUMMARY

Knowledge of fetal presentation and position at term are critical in predicting labor difficulties such as abnormal lie.

Some fetal presentations make vaginal birth virtually impossible for a normal-sized fetus: i.e., brow presentation and mentum posterior

Orientation of fetal lie and position by ultrasound requires knowledge of how the ultrasound beam transects the fetus

YOU MAY NOW TAKE THE QUIZ AND MOVE TO THE NEXT CHAPTER. YOU WILL NOT BE ABLE TO OPEN THE NEXT CHAPTER UNTIL YOU COMPLETE AND PASS THE QUIZ. YOU WILL HAVE AS MANY TRIES AS YOU NEED TO GET ALL THE ANSWERS CORRECT!

GULU Midwives Basic Obstetric POCUS

Chapter 9. Second-Third Trimester and Fetal Presentation