Pregnancy - Intrapartum Care Flashcards
Describe: Intrapartum care
is the care of the mother and fetus during labor.
Describe: Labor (1)
is the process by which products of conception are delivered from the uterus by progressive cervical effacement and dilatation in the presence of regular uterine contractions.
Describe: Braxton Hicks contractions (2)
- irregular contractions
- not associated with any cervical D or descent of fetus.
Regulation of the myometrial activity of the uterus relies on what? (3)
- fetal and maternal paracrine/autocrine factors, as well as intrinsic factors within myometrial cells
- This is because the uterus is not densely innervated.
- Four distinct physiologic phases of myometrial activity in pregnancy
Name: Four distinct physiologic phases of myometrial activity in pregnancy
- Myometrial inhibition
- Myometrial activation
- Stimulatory
- Involution
Describe the mechanism of this physiologic phase of myometrial activity in pregnancy: 0. Myometrial inhibition (2)
- During pregnancy, uterus remains quiescent because inhibitors active
- Putative inhibitors = progesterone, prostacyclin, relaxin, NO, placenta CRH
Describe the mechanism of this physiologic phase of myometrial activity in pregnancy: 1. Myometrial activation (3)
- Occurs as term approaches
- Uterus activated in response to uterotropins (i.e., E)
- Result: (a) uterus become primed; (b) have development of regular, rhythmic contractions
Describe the mechanism of this physiologic phase of myometrial activity in pregnancy: 2. Stimulatory (1)
Stimulation of primed uterus by uterotonic agonists (i.e., oxytocin, PGE2, PGF2a )
Describe the mechanism of this physiologic phase of myometrial activity in pregnancy: 3. Involution (2)
- Occurs after delivery
- Mediated by oxytocin
Name FETAL Factors promoting labor (2)
- Activation of fetal HPA axis → ↑ cortisol which acts on placenta → ↑ E production → ↑ E: progesterone ratio
- Result: (a) ↑ PGFa release; (b) ↑ myometrial response to oxytocin; (c) ↑ contractions
Name MATERNAL Factors promoting labor (2)
- Activation of maternal HPA axis→ possible activation of fetal HPA
- Oxytocin → ↑ PG receptors, ↑ oxytocin receptors, and ↑ gap junctions in uterine
Name MYOMETRIAL Factors promoting labor (2)
- ↑ Free intracellular Ca2+ → contraction of uterine myocyte cells
- Possible mechanotransduction through stretching or shortening
How many stages of labor are there?
4
Describe FIRST stage of labor 2)
Interval between onset of labor to full cervical dilation (10 cm). Divided into two phases.
- Latent phase: begins with onset of regular uterine contractions with slow cervical dilation up to ~3–4 cm
- Active phase: ↑ rate of cervical dilation to maximum, regular contractions, and descent of fetus
Describe the average duration of FIRST stage of labor (Nulliparous vs multiparous)
- Total:
- Nulliparous: ~10 h
- Multiparous: ~8h
- Latent:
- Nulliparous: ~6.5 h Prolonged > 20 h
- Multiparous: ~4.5 h Prolonged > 14 h
- Active:
- Nulliparous: Cervical dilation 1.2 cm/h Fetal descent>1 cm /h
- Multiparous: Cervical dilation 1.5 cm /h Fetal descent>2 cm /h
Describe SECOND stage of labor (1)
Interval between full cervical dilation and delivery of infant
Describe the average duration of SECOND stage of labor (Nulliparous vs multiparous)
- Nulliparous: ~50min Prolonged (no epidural) > 2 h
- Multiparous: ~20min Prolonged (no epidural) > 1 h
Describe THIRD stage of labor and average duration (1)
- Interval between delivery of infant and delivery of placenta
- ~10 min Prolonged if > 30 min
Describe FOURTH stage of labor and average duration (2)
- Interval from delivery of placenta through to the resolution of physi- ologic Ds of pregnancy
- Avg. duration: 6 wk
Describe the cardinal movements of labor (7)
Sequence of movements, involving Ds in position of the fetal head that enables the fetus to successfully negotiate the pelvis during labor.
- Engagement—widest diameter of the fetal head (biparietal diameter) enters the maternal pelvis below the plane of the pelvic inlet.
- Descent—downward passage of the presenting part through the pelvic floor. Greatest rate is during the second stage of labor.
- Passive flexion of the fetal occiput permits the smallest diameter of the fetal head (suboccipitobregmatic ~9.5 cm) to be presented for optimal passage through the p elvis.
- Internal rotation—rotation of the occiput from its original position toward the symphysis pubis (OA), which is ideal, or toward the sacrum (OP). This enables the AP diameter of the fetal head to line up with the AP diameter of the pelvic outlet.
- Extension—delivery of the fetal head by extension and rotation of the occiput around the symphysis.
- Restitution and external rotation—with the fetus’ head free of resistance, it un- twists, causing the occiput and spine to line in the same plane.
- Expulsion—delivery of the anterior shoulder under the symphysis pubis followed by quick expulsion of the rest of the body.

Name: Signs and Sx of Onset of Labor (3)
- Regular, painful contractions that are increasing in intensity and frequency
- Vaginal discharge that is thick, mucous-like, or slightly bloody
- Gush or trickle of vaginal fluid that is watery
Describe: Birth Plans (2)
- The pt and her partner may arrive with a birth plan.
- Review the birth plan early on in labor together with the pt and her partner to improve patient–physician communication and to provide culturally sensitive care.
Describe history of labor (3)
- Establish the age, GTPAL, gestational age, pattern of contractions, Hx of rupture of membranes, vaginal bleeding, and presence of fetal movements
- Review current pregnancy Hx, complications during this pregnancy, and results of routine antenatal investigations (e.g., detailed anatomic ultrasound, gestational diabetes screening, GBS)
- Review PMHx, SxHx, meds, allergies, and social Hx

