Fetal parameters ( lie , presentation , presenting part , attitude , denominator , position )

Summary

This script discusses fetal presentation and position in relation to the maternal spine and pelvis. It explains that the most common presentation is longitudinal, but can also be transverse or oblique. The part of the fetus in the lower uterine pool is typically achephalic, with bridge and shoulder presentations being less common. The script further details the concept of the presenting part, attitude, and denominator, and describes various positions of the fetus within the maternal pelvis, including anterior, posterior, and transverse positions, using vertex presentation as a primary example.

Takeaways

• 🔍 The long axis of the fetus usually aligns longitudinally with the maternal spine, but it can also be transverse or oblique.
• 👶 Presentation refers to the part of the fetus that occupies the lower uterine pool, commonly the head (cephallic), but can also be the buttocks (breech), shoulder, or other parts like in compound presentation.
• 🤰 In 3% of term pregnancies, the presentation is breech, and in 0.5%, it's shoulder presentation.
• 📍 The presenting part is the part of the fetus that overlies the internal os, such as the vertex in a well-flexed head or the brow in an extended head.
• 🧍 Attitude describes the relationship between different parts of the fetus, with flexion being the most common to maintain an ovoid shape within the uterus.
• 🤷‍♀️ Exceptions to the typical fetal attitude include an extended head in cephalic presentation or extended legs in breech presentation.
• 📝 The denominator is a fixed bony point on the presenting part, used to describe the position of the fetus, such as occiput in vertex presentation or sacrum in breech presentation.
• 📍 Position is the relationship of the denominator to different compartments of the maternal pelvis, with eight possible positions: three anterior, three posterior, and two transverse.
• 📌 Vertex presentation can have various positions, such as left occipital anterior, right occipital anterior, and direct occipital anterior, depending on the direction of the occiput.
• 🔄 There are also posterior and transverse positions for the fetus, like right occipitoposterior and left occipital transverse.

Q & A

What is the most common relationship of the long axis of the fetus to the maternal spine?

The most common relationship is a longitudinal lie, meaning the long axis of the fetus is parallel to the long axis of the maternal spine.

What are the different types of presentations of the fetus in the uterus?

The different types of presentations include longitudinal, transverse, and oblique presentations.

What is the most common part of the fetus that occupies the lower pool of the uterus?

The most common part is the achephalic presentation, which means the head of the fetus is not the presenting part.

What is the term used for a presentation where a hand is felt besides a presenting head?

This is called a compound presentation.

What is the presenting part in a well-flexed and slightly deflected head?

In a well-flexed and slightly deflected head, the presenting part is the vertex.

What is meant by the term 'attitude' in fetal positioning?

Attitude refers to the relationship of different parts of the fetus to one another, with flexion being the most common to maintain an oval shape corresponding to the uterine void.

What is the denominator in vertex presentation?

In vertex presentation, the denominator is the occiput.

What are the three anterior positions of the occiput in vertex presentation?

The three anterior positions are left occipital anterior, right occipital anterior, and direct occipital anterior.

What are the two transverse positions of the occiput in vertex presentation?

The two transverse positions are left occipital transverse and right occipital transverse.

What is the term used for the fixed bony point on the presenting part of the fetus?

The fixed bony point on the presenting part of the fetus is called the denominator.

Outlines

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🤰 Fetal Presentation and Positioning

This paragraph discusses the various aspects of fetal presentation and positioning within the uterus. It explains that the long axis of the fetus is typically longitudinally aligned with the maternal spine but can also be transverse or oblique. The concept of 'presentation' refers to the part of the fetus that occupies the lower uterine segment, often the head in a cephalic presentation. It also mentions that in rare cases, the presentation can be breech, shoulder, or compound. The 'attitude' of the fetus describes the relationship between different parts of the fetus, with flexion being the most common to maintain an oval shape that fits the uterus. Exceptions like extended head or leg positions are noted. The 'denominator' is identified as a fixed bony point on the presenting part, which varies with the type of presentation (e.g., occiput in vertex, mentum in face, frontal eminence in brow, sacrum in breech, and acromion in shoulder presentations). Lastly, 'position' describes the relationship of the denominator to the maternal pelvis, with eight possible positions detailed: three anterior, three posterior, and two transverse.

Keywords

💡Long axis

The long axis refers to the longest dimension of a structure, in this case, relating to the fetus and the maternal spine. In the context of the video, it is mentioned that the long axis of the fetus is most commonly aligned in a longitudinal line with the long axis of the maternal spine, which is a key aspect of fetal presentation during pregnancy.

💡Presentation

Presentation in obstetrics refers to the part of the fetus that occupies the lower part of the uterus and is closest to the birth canal. The script explains that the most common presentation is achephalic, meaning not head-first, and it can also be transverse or oblique. Presentation is crucial for determining the ease and safety of childbirth.

💡Attitude

Attitude describes the relationship of different parts of the fetus to one another, particularly how the body parts are positioned in relation to each other. The script mentions that flexion, or the bending of all body joints, is the universal attitude in fetuses to maintain an oval shape that corresponds with the uterine cavity, although exceptions like extension can occur.

💡Vertex presentation

Vertex presentation is a type of cephalic presentation where the baby's head is the first part to enter the birth canal. The script specifies that in a well-flexed and slightly deflected head, the vertex is the presenting part, indicating the baby's head is the leading part in the birth process.

💡Brow presentation

Brow presentation is a subtype of cephalic presentation where the baby's head is extended, and the brow is the presenting part. This is less common and may require specific interventions during childbirth, as mentioned in the script where the presenting part is the brow in an extended head.

💡Breech presentation

Breech presentation occurs when the baby's buttocks or feet are the first parts to enter the birth canal. The script notes that the denominator in a breech presentation is the sacrum, which is a significant factor in determining the approach to delivery.

💡Shoulder presentation

Shoulder presentation is a rare form of oblique presentation where a baby's shoulder is the first part to enter the birth canal. The script uses the term to illustrate an example of 'other' presentations, where the denominator is the acromion, which is the tip of the shoulder blade.

💡Compound presentation

Compound presentation is when two or more parts of the fetus are presenting at the same time, such as a hand alongside the presenting head. This is highlighted in the script as an example of an 'other' presentation, which can complicate the delivery process.

💡Denominator

In the context of fetal presentation, the denominator is a fixed bony point on the presenting part. The script explains how different denominators, such as the occiput in vertex presentation or the sacrum in breech presentation, are used to describe the position of the fetus within the maternal pelvis.

💡Position

Position refers to the relationship of the denominator to different compartments of the maternal pelvis. The script outlines eight positions (three anterior, three posterior, and two transverse), using examples such as left occipital anterior or right occipital posterior to describe the orientation of the fetus for childbirth.

💡Flexion

Flexion is the act of bending, and in the context of the script, it describes the universal attitude of a fetus where all body joints are flexed to maintain an oval shape that corresponds with the shape of the uterine cavity. This is a natural adaptation for the fetus to fit within the confined space of the womb.

Highlights

The long axis of the fetus is most commonly in a longitudinal line relative to the maternal spine.

Fetal presentation can be transverse or oblique, not just longitudinal.

The part of the fetus that occupies the lower uterine pool is known as the presentation.

Achephalic presentation is most common, occurring in the majority of cases.

Bridge presentation occurs in 3% of term pregnancies.

Shoulder presentation is seen in 0.5% of pregnancies.

Compound presentation is an example of 'other' presentations, such as when a hand is felt beside a presenting head.

The presenting part is the part of the presentation that overlies the internal os.

In kephalic presentation, the vertex is the presenting part in a well-flexed and slightly deflected head.

In an extended head, the presenting part is the brow, and in a fully extended head, it is the face.

Attitude refers to the relation of different parts of the fetus to one another, with flexion being the universal attitude.

Exceptions to the universal flexion attitude can occur, such as extension of the head in cephalic presentation.

The denominator is a fixed bony point on the presenting part, used to describe the presentation.

In vertex presentation, the occiput is the denominator, while in face presentation, it is the mentum.

In brow presentation, the frontal eminence is the denominator, and in breech presentation, it is the sacrum.

In shoulder presentation, the acromion is the denominator.

Position refers to the relation of the denominator to different compartments of the maternal pelvis, with eight possible positions.

There are three anterior positions: left occipital anterior, right occipital anterior, and direct occipital anterior.

There are three posterior positions, including right occipitoposterior and left occipital posterior.

There are two transverse positions: left occipital transverse and right occipitotransverse.

Transcripts

lie

is the relation of the long axis of the

fetus to the long

axis of the maternal spine

most commonly it is a longitudinal line

however it may be transverse

or oblique

presentation is a part of the fetus

which occupies the lower pool

of the uterus

most commonly it is achephalic

presentation

in three percent of term pregnancies the

presentation is

bridge

in point five percent of pregnancies

the presentation is shoulder and others

an example of other is compound

presentation

when a hand is felt besides a presenting

head

the presenting part is the part of the

presentation

which overlies the internal loss

in kephallic presentation for example in

a well-flexed

and the slightly deflected head the

presenting

part is vertex

in extended head the presenting part

is brow in fully extended head

the presenting part is face

attitude is the relation of different

parts of the fetus to one another

flexion is the universal attitude

all body joints are flexed to maintain

an avoid shape

that correspond with the shape of the

uterine or void

however exceptions may occur

such as extension of head in kefalic

presentation

or extension of legs in bridge

representation

denominator is a fixed bony point on the

presenting

part now i will write the presenting

part on the left side

and the itsy denominator on the right

side

in vertex representation occiput is the

denominator

in phase presentation it is mintum

in brow presentation it is frontal

eminence

in breach of presentation the

denominator is sacrum

while in shoulder presentation the

denominator is

acromion

position is the relation of the

denominator to different

compartments of maternal pelvis

there are eight positions three anterior

three posterior and two transverse

let's take vertex presentation with its

denominator the occiput

as an example here you see the occiput

directed anteriorly and to the left

and that's why it's called left

occipital anterior position

on the other side it becomes right

occipital anterior

and the windsor occiput is directly

behind the symphysis pubes

it's called direct occipital anterior

these are the three anterior positions

now

let's move to the posterior compartment

we have right occipitoposterior

left occipital posterior and the windsor

occiput

is directly anterior to the sacrum it's

called direct oxabito posterior

and finally there are two transverse

positions

left occipital transverse

and write occipito transfers