Normal Labor and Delivery Flashcards
What is labor defined as?
- Progressive cervical dilation resulting from regular uterine contractions that occur at least every 5 minutes and last 30-60 seconds
What is false labor?
- Braxton Hick contractions
- Irregular contractions without cervical change
How long is the suboccipitobregmatic diameter?
- 9.5 cm
How long is the occipitofrontal diameter?
- 11 cm
How long is the supraoccipitaomental diameter?
- 13.5 cm
- Longest anterior-posterior diameter of the head
How long is the submentobregmatic diameter?
- 9.5 cm
What is the average circumference of a term fetal head?
- 34.5 cm
- Measured in the occipitofrontal plane
What are the different pelvic shapes?
- Gynecoid
- Android
- Anthropoid
- Platypelloid
What is a gynecoid pelvis?
- Classic female type of pelvis
- Round at inlet
- Wide transverse diameter only slightly greater than the anteroposterior diameter
- Wide suprapubic arch
- Good prognosis for delivery
How does the head rotate in a gynecoid pelvis?
- Rotates into the occiput anterior (OA) position
What is an android pelvis?
Classic male type of pelvis
- Widest transverse diameter closer to the sacrum
- Prominent ischial spines
- Narrow pubic arch
- Amount of space is restricted and arrest of descent is common
- Poor prognosis for delivery
How does the head rotate in an android pelvis?
- Forced to be in the occiput posterior (OP) position
What is an anthropoid pelvis?
- Resembles ape pelvis
- Much larger anteroposterior than transverse diameter
- Creates a long narrow oval shape
- Narrow pubic arch
- Prognosis for delivery good
How does the head rotate in an anthropoid pelvis?
- Engages only in the anteroposterior diameter
- Usually in the OP position
What is a platypelloid pelvis?
- Described as a flattened gynecoid pelvis
- Short AP and wide transverse diameter
- Wide bispinous diameter
- Wide suprapubic arch
- Poor prognosis for delivery
How does the head rotate in a platypelloid pelvis?
- Has to engage in the transverse diameter
What is a diagonal conjugate?
- Approximated by measuring from the inferior portion of the pubic symphysis to the sacral promontory
- If > 11.5 cm the AP diameter of pelvic inlet is inadequate
What is a obstetric conjugate?
- Estimated by subtracting 2 cm from the diagonal conjugate
- Is the narrowest fixed distance through which the fetal head must pass through during a vaginal delivery
What is the palpate?
- Anterior surface of the sacrum which is usually concave
- Ischial spines to assess prominence
How is pelvic outlet measured?
- By measuring the ischial tuberosities and the pubic arch
- Measure between the ischial tuberosities (8.5 is adequate)
- Measure infrapubic angle (place thumb next to each inferior pubic ramus and estimate angle –> 90 degrees is good)
What does a MRI or CT do for pelvimetry?
- Used to look if clinical or obstetric history is suggestive of pelvic abnormalities
What is done on initial evaluation?
- Review prenatal records
- Identify complications of pregnancy
- Confirm gestational age
- Review pertinent laboratory findings
- Focused history
- PE
What is included in the focused history during the initial evaluation?
- Nature and frequency of contractions
- Loss of fluid
- Vaginal bleeding
What is included in the PE during the initial evaluation?
- Vital signs
- Fetal heart tones and contractions
- Cervical exam if appropiate
What is the fetal lie?
- Reference is maternal spine to fetus spine
- Determines if infant is longitudinal, transverse, or oblique
What is a part of the obstetric exam?
- Fetal lie
- Fetal presentation (presenting part to the pelvis)
- Cervical exam
What is a part of the cervical exam?
- Dilation
- Effacement
- Station
- Position
- Consistency
What are the leopold maneurvers?
- Series of 4 maneuvers
1. Palpate the fundus (fetal head vs buttocks vs transverse position)
2. Palpate for spine and fetal small parts
3. Palpate what is presenting in the pelvic with suprapubic palpation
4. Palpate for cephalic prominence (can feel chin or occipital protuberance if head isn’t deep in pelvis)
What is the dilation stage of the cervical exam?
- Check at level of internal os
- Range from closed to completely dilated at 10 cm
What is the effacement stage of the cervical exam?
- Thinning of the cervix occurs and is reported as a % change in length
- Normal cervical length is 3-5 cm
- Rang is thick to 100% effaced
What is the station stage of the cervical exam?
- Degree of descent of the presenting part of the fetus
- Measured in cm from presenting part to ischial spine
- When the bony portion of the head reaches the level of the ischial spines the station is zero
- Range is -5 to +5 cm
What are the consistency and position stages of the cervical exam?
- Commonly used to calculate Bishop score
What is the first stage of labor?
- Onset of true labor to complete cervical dilation
- Latent phase
- Active phase
What is the second stage of labor?
- Complete cervical dilation to delivery of infant
What is the third stage of labor?
- Delivery of infant to delivery of placenta
What is the fourth stage of labor?
- Delivery of placenta to stabilization of patient
What is the latent phase of stage 1 in labor?
- Period between onset of labor and is characterized by slow cervical dilation
What is the active phase of stage 1 in labor?
- Associated with a faster rate of dilation and usually begins when cervix is dilated to 6 cm
- Admit for labor at this stage in term gestations
What are the different durations during the first stage of labor?
- Primiparas - Typically 6-18 hours
- Multiparas - Typically 2-10 hours
What is the rate of dilation during the first stage of labor?
- Primiparas - 1.2 cm per hour
- Multiparas - 1.5 cm per hour
What management is done during the first stage of labor?
- Maternal position
- Fluids
- Labs
- Maternal and fetal monitoring
- Analgesia
How is maternal position changed during the first stage of labor?
- Patient may ambulate if head is engaged and reassuring monitoring is noted
- If lying in bed, encourage left lateral recumbent position
How fluids managed during first stage?
- IV used to hydrate patient and provide access to administer meds
- Oxytocin to augment labor or after delivery of placenta
What labs are done during the first stage?
- CBC and T&S
What maternal monitoring is done during the first stage?
- Obtain vitals every 1-2 hours while in labor
How is fetal monitoring done during the first stage?
- External monitoring
- Continuous
- Intermittent monitoring if pregnancy is uncomplicated pr complicated
What intermittent monitoring is done for an uncomplicated pregnacy?
- Monitor every 30 min in active first stage
- Monitor every 15 in second stage of labor
What intermittent monitoring is done for a complicated pregnancy?
- Monitor every 15 min in active phase and during second stage