Snapshot A 32-year-old G2P1 at 39 weeks of gestation presents to the labor and delivery ward. She states that she has been having contractions for the past 4 hours. Currently, she believes the contractions are about 5 minutes apart. She is placed in a room, and the resident comes to take a history and do an exam. On pelvic exam, the resident notes that the patient's cervix is 2 cm dilated and 20% effaced, and she is having regular contractions, consistent with latent labor. Introduction Stage Timing Description Notes Stage 1 Latent Starts with regular uterine contractions ≤ 20 hours if nulliparous ≤14 hours if multiparous Highly variable duration Cervix effaces and slowly dilates Continous FHR monitoring doppler fetal scalp electrode (FSE) Monitor uterine activity tocodynamometer contractions should be 200 mV/10 min internal uterine pressure catheter Analgesic epidural may cause post-dural headache post-partum meperidine Cervix dilates from 0 cm to 6 cm Active Cervix dilates from 6 cm to 10 cm 2-3.5 hours Dilation rate accelerates from latent stage Regular and intense contractions Cervix effaces and dilates quickly Fetal head progressively descends into the pelvis Ends at full cervix dilation of 10 cm Stage 2 Starts at complete cervical dilation of 10 cm ≤3 hours if nulliparous ≤2 hours if multiparous Baby undergoes all stages of cardinal movements - descent, flexion,internal rotation, extension, and external rotation Maternal effort accelerates delivery Pressure on perineum for control Once head delivered evaluate nuchal cord Deliver shoulders Gentle downward pressure on head deliver anterior shoulder easy upward force deliver posterior shoulder Deliver body Warm, dry, stimulate baby Clamp and cut cord Send umbilical cord blood for ABO & Rh testing blood gases Ends at delivery of baby Stage 3 Starts after baby is delivered ≤30 minutes Placenta separates and uterus contracts to establish hemostasis Wait for signs of placental separation uterus firms/rises in abdomen gush of blood lengthening of cord Apply gentle / constant traction may take 30 minutes placenta in clumps may indicate abnormal placentation If >30 minutes uterine massage oxytocin manual extraction with hand Ends at delivery of placenta Stage 4 Starts immediately postpartum 2 hours Period with significant physiologic changes Systematic evaluation of cervix vagina vulva perineum periurethra Monitor for postpartum complications Ends 2 hours postpartum Cervical changes during labor softening/ripening effacement thinning/shortening of cervix dilation widening of cervix pathophysiology breakage of disulfide bonds engagement of fetal head with cervix Fetal station describes position of fetal head relative to maternal ischial spines scale -5, -4, -3, -2, -1, 0, +1, +2, +3, +4, +5 -5 = initial position prior to labor 0 = at level of narrowest point of ischial spines +5 = at vaginal opening