CLINICAL CASE
Unit Two: Obstetrics
Section A: Normal Obstetrics
Objective 11: Intrapartum Care
Learning objectives
At the conclusion of this exercise, the student will be able to:
A. Describe the initial assessment of the laboring patient
B. Describe the stages and mechanism of normal labor and delivery
C. Understand and interpret methods of monitoring the mother and fetus
D. Describe management of normal delivery
E. Understand the indications for operative delivery
F. Describe immediate postpartum care of the mother
Martha is a 26-year-old G2P1 at 40 weeks gestation who comes to labor and delivery
noting several hours of frequent, painful uterine contractions. About an hour prior to
her arrival she noticed the start of intermittent leaking of fluid and passage of slightly
blood-tinged mucus per vagina. She states that the baby is moving normally. In
reviewing her chart, you find that she had an elevated 1-hour glucose screen of 150
with a normal 3-hour glucose tolerance test. She had an ultrasound at 17 weeks that
revealed a male fetus and was consistent with her last menstrual period dating. A
vaginal culture at 36 weeks revealed no group B streptococcus in the vagina. The
remainder of her prenatal care was uneventful. Her prior medical history is significant
for a work related lumbar spine strain and an appendectomy at age 12. She is allergic
to penicillin.
Physical exam
Her blood pressure is 96/54, pulse 92/minute, respirations are 20/minute and
temperature is 98F oral. Fetal heart rate (FHR) is in the 150s with good variability,
positive accelerations and no decelerations. Contractions are noted on the external
monitor every 2-3 minutes and make the patient very uncomfortable. The fetal back
is palpable at the right side of the maternal abdomen and the vertex is palpable
through the maternal abdomen just below her symphysis pubis. Cervical examination
reveals 3cm dilation, 80% effacement and a station of –2. Fluid taken from the vagina
is Nitrazine positive and leaves a fern pattern upon drying. This confirms spontaneous
rupture of membranes.
Two hours later, Martha has requested intravenous pain medication and she is given a
narcotic combined with an anti-emetic. Cervical exam at that time reveals 5cm
dilation, complete effacement and –1 station. FHR is reassuring. An hour later, the
narcotic has worn off and Martha is requesting an epidural. The anesthetist is alerted
but, first, another cervical exam is performed. This time, the cervix is 6cm dilated and
the vertex is at 0 station. The epidural is placed and dosed, with great relief to
Martha.
Two hours later, the epidural dose is beginning to wear off and the fetal heart rate
shown mild, intermittent variable decelerations. A cervical exam reveals 8 cm dilation
and a +1 station. The epidural is re-dosed. Martha sleeps after this and awakens to the
nurse coming to evaluate a fetal heart rate deceleration to the 80s that lasted about a
minute before recovering to the baseline 150s. A cervical exam reveals that the cervix
is now completely dilated and the vertex is at +2 station. The patient is instructed in
pushing technique. With the assistance of her husband and a friend, she pushes to
crowning and is taken to the delivery room for delivery. She delivers a male with
Apgar 9/9 over an intact perineum. The placenta delivers normally and Martha is
taken to the recovery room with her new baby, both in stable condition.
Diagnosis
Normal labor and delivery
Teaching points
1. Labor is defined as progressive dilation and effacement of the cervix in response
to regular uterine contractions. False labor is defined as contractions at term
that do not result in cervical change. This can be a frustrating situation both for
the pregnant woman and her physician since these ineffective contractions can
be quite uncomfortable. They can be managed with fluids, bed rest, hypnotics
or narcotics.
2. Initial assessment of the laboring patient involves evaluating the fetal heart
rate, fetal presentation, the condition of the cervix, and the timing and quality
of uterine contractions. Evaluation of maternal vital signs, current medical
conditions and current physical status are essential. Medical conditions that
might affect labor or delivery must be addressed, as must the patient’s prior
labor and delivery outcomes.
3. The Friedman curve is a graph plotting the progress of labor over time. The
Friedman curve plots cervical dilation and fetal descent over time and is a
means of determining whether or not labor is moving along normally. If labor is
not progressing, several interventions are employed. Oxytocin is used in the case
of inadequate contractions. Forceps or vacuum extraction are indicated in the
event of maternal exhaustion or for nonreassuring fetal heart tracing. Cesarean
delivery may be needed if there is evidence of cephalopelvic disproportion, fetal
malpresentation or fetal intolerance of labor.
4. Labor is divided into stages: 1st stage is from the onset of contractions and
cervical change to complete dilation; 2nd stage is from complete dilation to
delivery of the fetus; 3rd stage is from delivery of the fetus to delivery of the
placenta; some authors have described the first hour postpartum as the 4th
stage, during which there is a risk of postpartum hemorrhage.
5. The fetus descends through the maternal pelvis through various flexions and
rotations called the cardinal movements of labor. These include engagement,
where the leading bony part of the fetal vertex has reached the ischial spines
and the maternal sacrum is partially filled by the fetal head; descent, where the
fetal vertex is 1 or more centimeters below the ischial spines (+1 station or
more); flexion of the fetal head at the neck due to increased resistance against
the maternal pelvis; internal rotation, which occurs at the level of the ischial
spines as the biparietal diameter of the fetal head passes through the maternal
mid pelvis; and extension, where the fetal head extends and the head emerges
from the vagina.
6. Immediately postpartum, the mother is observed for alterations in vital signs or
postpartum hemorrhage. Vaginal blood flow (lochia) is evaluated and the uterus
is massaged to maintain a contracted state. Usually, oxytocin is administered
postpartum to assure uterine contractility and consequent decreased blood loss.