WEEK 2: NORMAL LABOR AND FOETAL MONITORING

Question 1

What is labor?

Answer 1

Presence of regular painful uterine contractions of increasing frequency and intensity that cause progressive cervical effacement and dilatation, accompanied by descent of presenting part and resulting in subsequent expulsion of products of conception.

Question 2

During labor, there may be a show and/or spontaneous rupture of membranes.

What is a show?

Answer 2

“Show” is the bloodstained mucus plug that is released from the cervix and expelled from the vagina at onset of labor.

Question 3

When do we say that the labor is normal?

Answer 3

*Term pregnancy (37- 42wks)
*Singleton
*Live fetus
*Vertex presentation
*Spontaneous onset
*Normal delivery achieved within normal time limits and in absence of complications
*Normal birth outcomes

Question 4

Describe the first stage of labor.

Answer 4

The first stage of labor
-Begins with onset of uterine contractions of sufficient frequency and intensity to cause cervical effacement and dilatation.

-Ends with fully cervical dilatation (10 cm).

Question 5

First stage of labor.

What is the average duration of labor?

What is primigravida?

What is multigravida?

State the average time for primigravida and multigravida.

Answer 5

The average duration is 12 hours.

-A “primigravida” is a woman who is pregnant for the first time.
-A “multigravida” is a woman who has been pregnant more than once

• (6–18 hours) in the primigravida

*Approximately 7 hours (2–10 hours) in the multigravida.

Question 6

Describe a graph of cervical dilation versus time.

Answer 6

A graph of cervical dilation versus time produces a characteristic sigmoid pattern in normal labor.

Progresses gradually and picks more rapidly at 6cm dilatation.

Question 7

Describe the latent phase of first stage of labor.

It can be it prolonged if it exceeds how many hours in primigravida and multigravida?

Answer 7

Latent phase of the first stage of labor

-Uterine contractions typically less frequent (at least 2/10min) but generate sufficient force to cause slow effacement and dilatation of the cervix.

-It is a slowly progressive phase from onset of labor pains to 3cm dilatation. (recently possibility of 5cm)

-It is prolonged if it exceeds 20h in PG and 14hr in multigravida.

Question 8

State the 3 DEGREES OF CERVICAL EFFACEMENT.

Answer 8

No effacement

75% effacement

100% effacement

Question 9

Describe the active phase of the first stage of labor.

Answer 9

Rapidly progressive phase from 4cm to full cervical dilatation (10cm).

Average rate-atleast 1.2cm/hr in PG and 1.5cm/hr in multigravida

Question 10

Describe the third stage of labor.

Answer 10

Begins immediately after delivery of the fetus and ends with the delivery of the placenta and fetal membranes.

Maximum acceptable duration of 30 min

Question 10

Describe the second stage of labor.

Answer 10

Starts from full cervical dilatation (10cm) and ends with delivery of the fetus.

*Associated with increased urge to bear down with each contraction

*Progress in 2nd stage is assessed by descent of presenting part.

*Median duration 50mins PG, 30min MG.

May be longer up to 3h in PG and up to 2h in MG with use of epidural anesthesia…

Question 10

Describe the fourth stage of labor.

Answer 10

Critical first hour postpartum

Monitor vital signs, PV bleeding and uterine contractility ¼ hourly.

Explore for and repair any laceration.

Question 11

Describe the normal labor presentation.

Answer 11

Occiput (vertex) presentations occur in approximately 95% of all labors.

Question 12

The mechanism of labor and delivery involves 7 cardinal movements.

Answer 12

1) Engagement.
The greatest transverse diameter of the head passes through the pelvic inlet.

2. Descent: Triggered by uterine contractions
   *Descent of PP is critical for delivery.
   *In a PG, descent may not occur until the onset of second stage.
   *In a multiparous woman, descent usually begins with engagement.

3) Flexion.
*When the descending head meets resistance from the cervix, pelvic walls or the pelvic floor, flexion of the fetal head normally occurs.

*The chin is brought into close contact with the fetal thorax.

*This movement causes a smaller diameter of fetal head to be presented to the pelvis than would occur if the head were not flexed.

4. Internal rotation: Midpelvis
   *This movement is associated with descent of the presenting part and usually is not accomplished until the head has reached the level of the ischial spines (station 0).
   *It encounters the levator ani muscles

*It involves the gradual turning of the occiput from its original position anticlockwise/anteriorly toward the symphysis pubis.

5) Extension of the fetal head.
*When the sharply flexed fetal head meets the vulva, the occiput is brought in direct contact with the inferior margin of the symphysis.

Because the vulvar outlet is directed upward and forward, extension must occur for the head to pass through.

The expulsive forces of the uterine contractions and the woman’s pushing, along with resistance of the pelvic floor, result in the anterior extension of the vertex in the direction of the vulvar opening.

6) External rotation: Sideways
After delivery of the head.
The shoulders rotate into an oblique or frankly anterior-posterior orientation with further descent.

This encourages the fetal head to return to its transverse position. This is also known as restitution.

7. Expulsion.
   After external rotation, the anterior shoulder appears under the symphysis and is delivered.
   The perineum soon becomes distended by the posterior shoulder.
   After delivery of the shoulders, the rest of the infant’s body is extruded quickly.

Question 13

Conduct of labor

Describe the 3 Ps for normal labor.

Answer 13

*Passage- both the bony and soft tissues

*Power- adequate and well-coordinated uterine contractions

*Passenger- appropriate size, presentation and position

*Psychological support- mother encouraged to bring a companion.

Question 14

Fetal monitoring.

State the 2 types.

Answer 14

1.External fetal monitoring
Uses device to record fetal heartbeat through the maternal abdomen.

-Intermittent auscultation with Pinard’s stethoscope

-Intermittent with a hand-held electronic Doppler ultrasound device/ sonicade

-Continuous using an external electronic fetal monitor/ cardiotocography (CTG)

2.Internal fetal monitoring

Question 15

Describe continuous external electronic fetal heart monitoring.

Answer 15

An ultrasound transducer placed on the mother’s abdomen conducts the sounds of the fetal heart to a computer.

The rate and pattern of the fetal heart are displayed on the computer screen and printed onto special graph paper.

Question 16

Describe internal fetal heart rate monitoring.

Answer 16

*Uses an electronic transducer connected directly to the fetal scalp in labor following rupture of membranes.

*A wire (spiral/scalp) electrode is attached to the fetal scalp through the cervical os and is connected to the monitor.

*It provides a more accurate and consistent transmission of the fetal heart rate

*It may be used when external monitoring of the fetal heart rate is inadequate or when closer surveillance is needed.

Question 17

State the 4 parameters measured on fetus during labour.

Answer 17

Heart rate and pattern

Descent of Presenting part

Presence and degree of meconium in the liquor, green baby poo.

PH

Question 18

Describe the parameters measured on the maternal

Answer 18

*Vitals-BP, P, Temp checked 4 hrly

*Contractions-frequency and intensity in 10 mins-half hourly

*Fluid input and output

*Urine testing; protein, glucose and acetone

*Progress-cervical dilatation 2-4hrly and descent of PP 2hrly

Question 19

The fetal heart rate-intermittent observations
Should be monitored immediately after a uterine contraction preferably in L. lateral position.

WHY?

Interval.
*First stage and 2nd stage for uncomplicated/low risk pregnancies

*1st stage and 2nd stage in complicated/high risk pregnancies

Answer 19

The fetal heart rate-intermittent observations
Should be monitored immediately after a uterine contraction preferably in L. lateral position

Monitoring the fetal heart rate (FHR) while the mother is lying in the supine position (flat on her back) during labor is generally discouraged because it can potentially lead to reduced blood flow to the uterus and placenta, which, in turn, may affect fetal well-being. There are several reasons why supine positioning is not recommended for FHR monitoring:

Inferior Vena Cava Compression: When a pregnant woman lies flat on her back (supine position), the weight of the growing uterus can compress the inferior vena cava, a major vein that carries deoxygenated blood from the lower body back to the heart. This compression can reduce blood return to the heart, leading to decreased cardiac output and lower blood pressure. As a result, blood flow to the uterus and placenta can be compromised.

Reduced Oxygen Delivery: Decreased blood flow to the uterus and placenta can result in reduced oxygen and nutrient delivery to the fetus. This can potentially lead to fetal distress and adversely affect the FHR.

FHR Variability: Changes in maternal position can affect FHR variability, which is a key indicator of fetal well-being. A supine position can lead to decreased variability in the FHR tracing, making it more challenging to interpret the fetal heart rate accurately.

Potential for Fetal Distress: Prolonged supine positioning may increase the risk of fetal distress, characterized by FHR abnormalities and other signs of inadequate oxygenation. Fetal distress can necessitate interventions to improve fetal oxygenation, such as changing the mother’s position, administering oxygen, or considering more advanced medical interventions.

To optimize blood flow to the uterus and placenta and reduce the risk of compromised fetal well-being, it is generally recommended that pregnant women are encouraged to change their position during labor. The left lateral position (left side-lying) is often preferred, as it shifts the weight of the uterus away from the inferior vena cava, improving blood flow and reducing the risk of vena cava compression.

Interval;

*Half hourly in the first stage and every 15min in 2nd stage for uncomplicated/low risk pregnancies

*Every 15mim in 1st stage and 5min in 2nd stage in complicated/high risk pregnancies

Question 20

State the normal range of the fetal heart rate.

What is variability?
What is its normal range?

State the markers for fetal distress.

Answer 20

Normal range 120-160b/min (WHO 100-180)

Variability -normal beat-to-beat variability 6–25 bpm.

-Persistent late decelerations
-Undetectable variability and
-Scalp pH< 7.21 is an indicator of fetal distress.

Question 21

What is early deceleration?

Describe the physiology of early fetal heartbeat deceleration.

Answer 21

Drop in fetal heart rate.

When contraction, there is temporary cut of blood supply to the fetus as the uterus contraction occludes the spiral arteries go through uterine vasculature, there is a decline in the fetal heartbeat. The heart rate increases as the contraction wears off.

Peak of contraction= lowest drop on the fetal heart rate.

Question 22

Describe late deceleration.

Answer 22

It is pathological, symbolizes compromission in the fetal deceleration.

The heart reaches lowest drop more than 30s when the contraction has long weared off when now it is expected for the fetal heart rate to be back to normal.

Question 23

Describe variable deceleration.

Answer 23

The fetal heart rate can occur at any time independent of the stage of contraction.

*It is usually non pathological
*Can be caused by cord obstruction.

Question 24

What is partograph?

Answer 24

Monitor labor.

Starts from 5cm to 10cm

Question 25

Amniotomy

State the role of ARM: artificial rupture of membrane.

Who should ARM be avoided in?

Answer 25

Artificial rupture of the membranes

*Reveals the color of the amniotic fluid (whether it is stained by meconium - a sticky, dark-green substance found in the intestine of the full-term fetus)

*It often shortens the length of labor if a woman is already contracting regularly by releasing prostaglandins.

*Avoid ARM in the HIV positive, to minimize risk of transmission of HIV to the baby.