Contributor: Meghan Hurley MD

Educational Pearls:

Pearls about labor:

• Labor is split into 3 stages.

• Stage 1 starts when the first persistent contractions are felt and goes up until the cervix is fully dilated and the mother starts pushing. Stage 1 is split into two phases: the latent phase (cervix is dilated from 0-4 cm), and the active phase (cervix dilates from 4-10 cm). The latent phase can take between 6 and 12 hours with contractions happening every 5 to 15 minutes. The active phase usually lasts 4-8 hours with contractions occurring as close as every 3 minutes.

• Stage 2 is the birth itself, lasting between 20 minutes and 2 hours.

• Stage 3 is the delivery of the placenta and typically takes 30 minutes.

• 37 weeks gestational age is the cutoff for preterm.

• Placenta previa: Condition when the placenta overlies the cervix. Classically presents as painless vaginal bleeding in the 3rd trimester. If suspected placenta previa, avoid a speculum exam. Placenta previa can be confirmed on ultrasound.

• If the baby is crowning in the ER then the baby should be delivered in the ER. The ideal presentation on crowning is head first (Vertex), specifically 'left occiput anterior'. In this position, the baby is head first and the head is facing towards the gurney at a slight angle. If the baby is coming out in a breech position then the provider should "elevate the presenting part" by maintaining pressure on the baby as the mother is wheeled to the OR for an emergency C-section.

• If a vertex-presenting baby is being delivered vaginally, after the head has been delivered an event called 'restitution' must occur to align the baby's shoulders properly. During this event, the baby goes from facing down towards the gurney to facing sideways.

• After restitution, the anterior shoulder should be delivered, followed by the posterior.

• After complete delivery, the cord should be clamped (after a 1-3 minute delay), with something sterile.

• Gentle downward traction on the cord helps to deliver the placenta. You can place pressure above the pubic bone to prevent the uterus from involuting during this process. This is not the same as a fundal massage which happens after the delivery of the placenta to help the uterus clamp down and prevent postpartum hemorrhage.

References

1. Hutchison J, Mahdy H, Hutchison J. Stages of Labor. 2023 Jan 30. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2023 Jan–. PMID: 31335010.

2. Lavery JP. Placenta previa. Clin Obstet Gynecol. 1990 Sep;33(3):414-21. doi: 10.1097/00003081-199009000-00005. PMID: 2225572.

3. Qian Y, Ying X, Wang P, Lu Z, Hua Y. Early versus delayed umbilical cord clamping on maternal and neonatal outcomes. Arch Gynecol Obstet. 2019 Sep;300(3):531-543. doi: 10.1007/s00404-019-05215-8. Epub 2019 Jun 15. PMID: 31203386; PMCID: PMC6694086.

Summarized by Jeffrey Olson MS2 | Edited by Meg Joyce & Jorge Chalit, OMSII