Normal labor progresses through four stages: first stage of dilation, second stage of baby delivery, third stage of placenta delivery, and fourth stage of recovery. The first stage has latent and active phases where the cervix dilates from 0-10 cm. Abnormal labor can occur if there are issues like large baby size, fast or slow progression, or medical complications. Some types of abnormal labor include shoulder dystocia, uterine rupture, precipitous labor, and postpartum hemorrhage. Preterm labor is when labor starts before 37 weeks of pregnancy.

1. NORMAL &
ABNORMAL LABOR
DR. SHAZIA IQBAL
ASSISTANT PROFESSOR (OBSTETRICS & GYNAECOLOGY)
DIRECTOR OF MEDICAL EDUCATION UNIT
FACULTY OF MEDICINE
VISIONCOLLEGE OF MEDICINE, RIYADH

2. • Normal labor.
• Stages of labor.
• Machnism of labor.
• Abnormal labor.
• stages of abnormal.
• Types of labor.

3. WHAT IS NORMAL LABOR?
• Normal labor is defined as uterine contractions that result in progressive dilation
and effacement of the cervix.
• By following thousands of labors resulting in uncomplicated vaginal deliveries,
time limits and progress milestones have been identified that define normal labor.
• Failure to meet these milestones defines abnormal labor, which suggests an
increased risk of an unfavorable outcome.
• Thus, abnormal labor alerts the obstetrician to consider alternative methods for a
successful delivery that minimize risks to both the mother and the infant.

4. • Every woman's labor is unique, even from one pregnancy to the next. Sometimes
labor is over in a matter of hours.
• In other cases, labor tests a mother's physical and emotional stamina.
• You won't know how labor and childbirth will unfold until it happens.
• You can prepare, however, by understanding the typical sequence of events of
labor stages:

5. STAGE OF LABOR
• There are 4 stages of labor:
• 1. First stage of labor
• a. Latent Phase
• b. Active Phase
2. Second stage of Labor
• 3. Third stage of Labor
• 4. Fourth stage of Labor

6. WHAT ARE THE STAGES OF LABOR?
• Labor happens in three stages and can actually begin weeks before you give birth:
• The first stage starts once contractions begin and continues until you’re fully dilated,
which means being dilated 10 centimeters, or 4 inches. This means your cervix has
opened completely in preparation for childbirth.
• The second stage is the active stage, during which you begin to push downward. It starts
with complete dilation of the cervix and ends with the birth of your baby.
• The third stage is also known as the placental stage. This stage begins with the birth of
your baby and ends with the completed delivery of the placenta.
• Most pregnant women go through theses stages without experiencing any problems.
Some women, however, may experience abnormal labor during one of the three stages
of labor.

7. • First Stage of Labor:
• Begins with onset of regular uterine contraction
• Ends with complete cervical dilation at 10 cm
• Latent Phase:
• Contractions become progressively stronger longer and more frequent and
coordinated
• Cervix effaces but shows minimal dilation
• • Duration:
• (May be intermittent over several days or may last only few hours)
• - Nulliparas: Average 8 hours
• - Multiparas: Average 5 hours

8. • Active Phase:
• • Cervix dilates usually from 3-4 cm to full dilation i.e. 10 cm
• • Duration more predictable
• • Duration and Rates
• - Nullipara: 5 hours; 1.2 cm/hour
• Multipara: 2 hours; 1.5 cm/hour

9. • Second Phase:
• Begins with complete cervical dilation
• Ends with delivery of the baby
• Third Stage:
• Begins with the delivery of baby
• • Ends with delivery of placenta
• Placenta separation from uterine wall occurs as the result of myometrium contraction shear
anchoring villi
• Duration:
• - <30 minutes in all women

10. • Fourth Stage:
• • First one hour after delivery
• • Vital signs and any evidence of uterine atony or postpartum hemorrhage
• Perineum inspection for any signs of hematoma formation
• • Mother should be seen every 15 mins
• • Newborn undergoes initial assessment

11. MECHANICS OF LABOUR
• The 3Ps
• Power.
• Passage.
• Passenger

12. NORMAL LABOR
• There are five classical steps in the normal mechanism of labor. They are:
• Descent
• Flexion
• Internal Rotation
• Extension
• External Rotation
• Usually, labor progresses in this fashion, if the fetus is of average size, with a normally positioned
head, in a normal labor pattern in a woman whose pelvis is of average size and gynecoid in shape.
• There is overlap of these mechanisms. The fetal head, for example, may continue to flex or increase
its flexion while it is also internally rotating and descending.

13. Descent: As the fetal head engages
and descends, it assumes an occiput
transverse position because that is
the widest pelvic diameter available
for the widest part of the fetal head.
Flexion: While descending through the pelvis, the fetal head
flexes so that the fetal chin is touching the fetal chest. This
functionally creates a smaller structure to pass through the
maternal pelvis. When flexion occurs, the occipital (posterior)
fontanel slides into the center of the birth canal and the anterior
fontanel becomes more remote and difficult to feel. The fetal
position remains occiput transverse.
Internal Rotation: With further descent,
occiput rotates anteriorly and the fetal
head assumes an oblique orientation. In
some cases, the head may rotate
completely to the occiput anterior
Extension: The curve of the hollow of
the sacrum favors extension of the
fetal head as further descent occurs.
This means that the fetal chin is no
longer touching the fetal chest
External Rotation: The shoulders
rotate into an oblique or frankly
anterior-posterior orientation with
further descent. This encourages the

14. VIDEO

15. ABNORMAL LABOR
• What is abnormal labor?
• Abnormal labor may be referred to asdysfunctional labor, which simply means
difficult labor or childbirth. When labor slows down, it’s called protraction of
labor. When labor stops altogether, it’s called arrest of labor.

16. CAUSES OF ABNORMAL LABOR
1-Abnormalities of the explusive forces:
. Weak uterine contractions
Discordemoted contractions
Inadequate voluntary muscle effect.
•
2-Abnormal presentation, position or development
•
3-Abnormal maternal bony pelvis
•
4-Abnormalities of the birth canal

17. TYPES OF ABNORMAL LABOR
• Macrosomia
• Macrosomia occurs when a newborn is much larger than average. A newborn is
diagnosed with macrosomia if they weigh more than 8 pounds, 13 ounces,
regardless of when they’re born. Approximately 9 percent of babies born
worldwide have macrosomia.
• This condition can cause problems during childbirth that can sometimes result in
injury. It also puts the baby at an increased risk for health problems after birth.
There are more risks to the mother and baby when a baby’s birth weight is
greater than 9 pounds, 15 ounces.

18. • Precipitous labor
• On average, the three stages of labor last about six to 18 hours. With precipitous
labor, these stages progress much more quickly, lasting only three to five hours.
Precipitous labor, also called rapid labor, may occur for several reasons:
• uterus is contracting very strongly, helping to push the baby out more rapidly.
• birth canal is compliant, making it easier for the baby to leave the womb.
• have a history of precipitous labor.
• baby is smaller than average.
• Precipitous labor presents several risks for the mother.
• These include vaginal or cervical tearing, heavy bleeding, and shock following birth

19. • Shoulder dystocia
• Shoulder dystocia occurs when the baby’s head is delivered through the
vagina, but their shoulders get stuck inside the mother’s body. This usually isn’t
discovered until labor has begun, so there’s no way to predict or prevent it.
• Uterine rupture
• A uterine rupture is a tear in the wall of the uterus, usually at the site of a
previous incision. This condition is rare, but it’s most often seen in women
had uterine surgery or who have previously given birth by cesarean delivery.

20. • Postpartum hemorrhage
• Postpartum hemorrhage occurs when there’s excessive bleeding following
childbirth, usually after delivery of the placenta.
• While a woman will usually lose about 500 milliliters of blood after childbirth,
• A postpartum hemorrhage will cause a woman to lose nearly double that
The condition is most likely to occur after birth by cesarean delivery.
• It may happen if an organ is cut or if your doctor doesn’t stitch the blood
properly.

21. PRETERM LABOR
• What is preterm labor?
• Preterm labor is labor that starts before 37 completed weeks of pregnancy. Labor is
when the uterus regularly tightens and the cervix starts to thin and open. This lets the
baby (fetus) enter the birth canal.
•
causes preterm labor:
• Infections
• Vaginal bleeding
• Hormone changes
• Stretching of the uterus. This might be from being pregnant with more than 1 baby,
a large baby, or too much amniotic fluid.

22. HOW IS PRETERM LABOR DIAGNOSED?
• An electronic monitor is used to check how often contractions are happening
and how long they last.
• This monitor has a small device (transducer) placed over your belly with a belt.
• The transducer detects and sends information about the contractions to the
monitor.
• Your baby's heart rate is also usually monitored.

23. REFERANCE
• https://brooksidepress.org/Products/Military_OBGYN/Textbook/LaborandDelivery
/mechanism_of_normal_labor.htm
• https://emedicine.medscape.com/article/273053-overview
• https://www.stanfordchildrens.org/en/topic/default?id=
• https://www.healthline.com/health/pregnancy/