Labor & Delivery

Varicella, rubella, measles, mumps, and polio vaccines consist of attenuated live viruses and should not be administered during pregnancy because of a theoretic risk to the fetus.

Biophysical profile
BPP is based on FHR monitoring (generally NST) in addition to four parameters observed on real-time ultrasonography:
  • amniotic fluid volume
  • fetal breathing
  • fetal body movements
  • fetal body tones.

Each parameter gets a score of 0 to 2. A score of 8 to 10 is considered normal, a score of 6 is equivocal, and a score of 4 or less is abnormal and prompts delivery.

Bishop Score

0 cm
1-2 cm
3-4 cm
>5 cm
Fetal station
-1, 0
+1, +2

Bishop score of >8 is good.

Montevideo Unit
Variation of intrauterine pressure (IUP) from baseline times # contractions in 10 min period
200+ is adequate

Labor: contractions causing cervical change
Lie: orientation of fetus in uterus (assessed with Leopold maneuver). Ex. transverse
Presentation: breech/vertex
Position: anything but OA can lead to prolonged labor/ increased rate of CS. Palpate sutures to detect.

Stages of labor

  1. Onset to complete dilation (10-12 hours in primigravida, 6-8 in multiparous)
    1. Latent phase: 0-3cm (slow)
    2. Active phase: 3-9cm (fast). 1.0cm/hr is 5th percentile
      1. Active phase arrest: no change in cervix for 2 hours with adequate ctx
  2. Completely dilated cervix to delivery of infant
  3. Infant delivery to delivery of placenta

Cardinal movements of labor

  • Engagement
  • Descent
  • Flexion
  • Internal rotation
  • Extension
  • External rotation

Rupture of membranes

  • SROM/AROM = spontaneous/artificial
  • PROM: premature – before labor has begun (give ampicillin)
  • PPROM: preterm premature
  • Prolonged PROM- 18+ hours before the onset of labor
  • Diagnosis
    • Pool test - check for fluid in vagina
    • Nitrazine blue: detects base in the vaginal fluid. Amniotic fluid is basic
    • Fern test
    • Oligohydramnios in previously normal fluid level
    • Indigo dye in amniocentesis checked with tampon
  • Indications
    • Deliver if 36+ weeks
    • Don’t deliver if less than 32 weeks

Pelvic girdle orientations

  • Gynecoid: ideal
  • Android: ideal brim, but ischial spines narrow
  • Anthropoid: oblong
  • Pladypoid: wide

Obstetric conjugate: sacroiliac notch to pubic sympysis Augmentation/induction

  • Indications:
    • Postterm (42+weeks)
    • Preeclampsia
    • PROM
    • Nonreassuring FHTs
    • IUGR
  • Agents
    • PGE2 gel or pessary (Cervadil)
      • Contraindicated w/maternal asthma/glaucoma
      • Contraindicated if >1 prior CS
      • Can’t be immediately turned off like pitocin, bad if tetany occurs
    • Misoprostol - Ctx only no ripening(?)
    • Mechanical: Foley bulb