1
OB Exam 2
Lightening or dropping - The baby's head settles
deeper into the pelvis, causing increased pressure on
the bladder and relief from breathing difficulties.
Bloody show - Passing of blood-tinged mucus from
the cervix as it dilates. -
Rupture of membranes - The amniotic sac breaks and
fluid leaks out.
The main signs of labor
include: Contractions - Regular, increasingly intense uterine
contractions that cause progressive cervical
dilation and effacement.
Backache - Persistent low backache due to pelvic
joint relaxation.
- Cramps - Menstrual-like cramps in the lower
abdomen. - Loose bowel movements - The
intestines clear out in preparation for labor.
What does dilation refer Dilation refers to the opening and widening of the
to during labor? cervix during labor.
What is the range of dilation Dilation progresses from being closed (0 cm dilated)
in centimeters? to fully dilated (10 cm).
What is effacement in the Effacement is the thinning and shortening of the
context of labor? cervix as it prepares for delivery.
How is effacement Effacement is measured in percentages from 0% to 100% effaced.
measured?
What does station describe Station describes the position of the baby's
in labor? presenting part in relation to the ischial spines of
the mother's pelvis.
What do negative numbers Negative numbers indicate the baby is above the ischial spines.
,2
indicate in station?
What does 0 station mean? 0 station means the baby is at the ischial spines.
What do positive Positive numbers mean the baby has descended
numbers indicate in below the ischial spines.
station?
,3
Increased cardiac output: Cardiac output rises by 12-
31% in the first stage of labor and even higher in the
second stage. This is primarily due to an increase in
stroke volume as 300-500 mL of blood is shunted
from the uterus into the maternal circulation with
contractions.
2. Blood pressure changes: Both systolic and
diastolic blood pressures tend to increase during
cardiovascular changes
contractions and return to baseline between
during labor
contractions. Systolic pressure rises more than
diastolic.
3. Risk of supine hypotension: The laboring woman is
at risk for supine hypotension when the vena cava
and aorta are compressed by the weight of the
uterus in the supine position. 4. Increased white
blood cell count: The maternal white blood cell count
rises during labor. 5. Immediate postpartum increase
in cardiac output: Immediately after birth, cardiac
output increases by 60-80% over prelabor values
due to the influx of blood from the uteroplacental
bed. It returns to prelabor levels within 1 hour.
Upright positions (walking, standing, sitting, squatting):
These utilize gravity to promote fetal descent and
enhance contractions. They are associated with
shorter labors and less need for interventions.
Side-lying (lateral): This improves uteroplacental
blood flow and fetal oxygenation. It's a good option
when lying down.
Positions during labor
Hands-and-knees: Helpful if the baby is posterior,
as it can facilitate rotation and descent. Squatting
during contractions: Increases pelvic diameters,
allowing better fetal positioning.
, 4
Birthing beds allow women to easily change
positions (sitting, reclining, side-lying) without
climbing in/out of bed. Ambulation and upright
positioning are recommended unless medically
contraindicated. Avoiding supine positions prevents
vena cava compression.
Begins with the onset of regular contractions and
What is the first stage of ends with full cervical dilation (10 cm). It has an early
labor?
latent phase focused on cervical effacement, and an
active phase of more rapid dilation.
Begins with full cervical dilation and ends with the
What is the second stage
birth of the baby. It consists of a latent phase of
of labor?
passive descent, and an active pushing phase.
Begins immediately after the birth of the baby and
What is the third stage of
labor? ends with the delivery of the placenta and
membranes.
What is the fourth stage Refers to the first 1-4 hours after delivery of the
of labor? placenta, during which the mother is monitored for
bleeding and uterine tone.
primary powers involuntary uterine contractions
secondary powers Use of abdominal muscles to push in the second stage of labor
What is the most common Cephalic presentation (head first)
fetal presentation?
What percentage of births 97-98%
are cephalic
presentations?
OB Exam 2
Lightening or dropping - The baby's head settles
deeper into the pelvis, causing increased pressure on
the bladder and relief from breathing difficulties.
Bloody show - Passing of blood-tinged mucus from
the cervix as it dilates. -
Rupture of membranes - The amniotic sac breaks and
fluid leaks out.
The main signs of labor
include: Contractions - Regular, increasingly intense uterine
contractions that cause progressive cervical
dilation and effacement.
Backache - Persistent low backache due to pelvic
joint relaxation.
- Cramps - Menstrual-like cramps in the lower
abdomen. - Loose bowel movements - The
intestines clear out in preparation for labor.
What does dilation refer Dilation refers to the opening and widening of the
to during labor? cervix during labor.
What is the range of dilation Dilation progresses from being closed (0 cm dilated)
in centimeters? to fully dilated (10 cm).
What is effacement in the Effacement is the thinning and shortening of the
context of labor? cervix as it prepares for delivery.
How is effacement Effacement is measured in percentages from 0% to 100% effaced.
measured?
What does station describe Station describes the position of the baby's
in labor? presenting part in relation to the ischial spines of
the mother's pelvis.
What do negative numbers Negative numbers indicate the baby is above the ischial spines.
,2
indicate in station?
What does 0 station mean? 0 station means the baby is at the ischial spines.
What do positive Positive numbers mean the baby has descended
numbers indicate in below the ischial spines.
station?
,3
Increased cardiac output: Cardiac output rises by 12-
31% in the first stage of labor and even higher in the
second stage. This is primarily due to an increase in
stroke volume as 300-500 mL of blood is shunted
from the uterus into the maternal circulation with
contractions.
2. Blood pressure changes: Both systolic and
diastolic blood pressures tend to increase during
cardiovascular changes
contractions and return to baseline between
during labor
contractions. Systolic pressure rises more than
diastolic.
3. Risk of supine hypotension: The laboring woman is
at risk for supine hypotension when the vena cava
and aorta are compressed by the weight of the
uterus in the supine position. 4. Increased white
blood cell count: The maternal white blood cell count
rises during labor. 5. Immediate postpartum increase
in cardiac output: Immediately after birth, cardiac
output increases by 60-80% over prelabor values
due to the influx of blood from the uteroplacental
bed. It returns to prelabor levels within 1 hour.
Upright positions (walking, standing, sitting, squatting):
These utilize gravity to promote fetal descent and
enhance contractions. They are associated with
shorter labors and less need for interventions.
Side-lying (lateral): This improves uteroplacental
blood flow and fetal oxygenation. It's a good option
when lying down.
Positions during labor
Hands-and-knees: Helpful if the baby is posterior,
as it can facilitate rotation and descent. Squatting
during contractions: Increases pelvic diameters,
allowing better fetal positioning.
, 4
Birthing beds allow women to easily change
positions (sitting, reclining, side-lying) without
climbing in/out of bed. Ambulation and upright
positioning are recommended unless medically
contraindicated. Avoiding supine positions prevents
vena cava compression.
Begins with the onset of regular contractions and
What is the first stage of ends with full cervical dilation (10 cm). It has an early
labor?
latent phase focused on cervical effacement, and an
active phase of more rapid dilation.
Begins with full cervical dilation and ends with the
What is the second stage
birth of the baby. It consists of a latent phase of
of labor?
passive descent, and an active pushing phase.
Begins immediately after the birth of the baby and
What is the third stage of
labor? ends with the delivery of the placenta and
membranes.
What is the fourth stage Refers to the first 1-4 hours after delivery of the
of labor? placenta, during which the mother is monitored for
bleeding and uterine tone.
primary powers involuntary uterine contractions
secondary powers Use of abdominal muscles to push in the second stage of labor
What is the most common Cephalic presentation (head first)
fetal presentation?
What percentage of births 97-98%
are cephalic
presentations?
