Labor and Birth DSG 2023 (1)

Labor and Birth Instructor: Assoc. Prof. Dr. Dilek Sarpkaya Güder, Nursing Faculty

Content Overview

  • Onset of Labor

  • Maternal Signs of Approaching Labor

  • The Three Ps of Labor and Delivery

  • Stages of Labor

  • Birth

Onset of Labor

  • Typically occurs between 38 and 42 weeks of gestation, though variations may occur based on individual circumstances.

  • Characterized by:

    • Regular, rhythmic contractions that change in frequency, intensity, and duration over time.

    • Progressive cervical dilation and effacement.

Possible Causes of the Onset of Labor

Maternal Factor Theories

  1. Uterine Muscle Stretching: As the uterus expands, stretching occurs which leads to the release of prostaglandins, promoting contractions.

  2. Pressure on Cervix: Increased pressure stimulates nerve receptors in the cervix, leading to the release of oxytocin (known as the Ferguson reflex), a critical hormone in initiating labor.

Hormonal Changes

  • Oxytocin: Levels rise dramatically during labor, reaching a peak during the second stage, facilitating contractions and cervical dilation.

  • Prostaglandin: Works together with oxytocin to promote rhythmic contractions necessary for labor.

  • Estrogen/Progesterone Ratio: A decrease in progesterone levels allows estrogen levels to rise, which in turn stimulates uterine contractions.

Fetal Factor Theories

  1. Placental Aging: As the placenta matures and begins to lose its efficiency, it sends signals that can trigger contractions.

  2. Fetal Cortisol: Increased fetal cortisol levels can reduce progesterone and stimulate prostaglandin production, leading to contractions.

  3. Prostaglandin Production: Produced by fetal membranes, enhances uterine readiness for labor.

Maternal Signs of Approaching Labor

  • Lightening: The descent of the fetal head into the pelvis is often noted by mothers as a change in abdominal shape, usually occurring around 38 weeks.

  • Bloody Show: Passage of blood-tinged cervical mucus occurs as the cervix begins to dilate, indicating that labor may be approaching.

  • Rupture of Membranes: Also known as “breaking of the water,” this can happen before the onset of labor and may require immediate medical assessment.

  • Uterine Contractions: Noticeable tightening and relaxation of the uterus that helps in cervical dilation and fetal descent.

Determining True Versus False Labor

  • True Labor: Contractions that are regular and increase in intensity, associated with cervical changes (effacement and dilation).

  • False Labor (Braxton Hicks): Characterized by irregular contractions that may decrease with activity, serving as a preparatory phase without leading to true labor.

The Three Ps of Labor and Delivery

  1. Power: Refers to the forces expelling the fetus:

  • Primary Power: Involuntary uterine contractions that create progress in labor.

  • Secondary Power: Voluntary maternal efforts, typically used during the second stage of labor for pushing.

  • Characteristics of Uterine Contractions:

    • Intensity: Classified as mild, moderate, or strong, impacting the mother's ability to cope with labor.

    • Frequency: The duration from the beginning of one contraction to the start of the next.

    • Duration: Time measured from the onset of a contraction to its conclusion.

  1. Passenger: Refers to the fetus and its position.

  • Fetal Attitude: The relationship of the fetal head to the spine (complete flexion, moderate flexion, deflexion).

  • Fetal Lie: The relationship of the fetal long axis (spine) to the mother’s long axis. Types include:

    • Longitudinal: The most common lie with fetus either cephalic or breech.

    • Transverse: Fetus lies sideways across the mother’s pelvis.

    • Oblique: Fetus is lying at an angle.

  • Fetal Position and Presentation: Alterations based on the presenting part, including:

    • Cephalic: Head first, the optimal position for delivery.

    • Breech: Buttocks or legs first, may complicate delivery.

    • Shoulder: Presents shoulder first, requires careful medical maneuvering.

  1. Passage: Describes the maternal bony pelvis shape and size, which significantly influences delivery.

  • Includes pelvic classifications:

    • Gynecoid: Ideal type for delivery.

    • Android: More male-shaped, can complicate labor.

    • Anthropoid: Slightly oval, favorable for vaginal birth.

    • Platypelloid: Flattened shape, often poses challenges during delivery.

Stages of Labor

Overview

  1. First Stage: Onset of labor to full dilation (up to 10 cm).

  2. Second Stage: Full dilation to delivery of the newborn.

  3. Third Stage: Delivery of the infant to delivery of the placenta.

  4. Fourth Stage: Postpartum period focusing on maternal recovery.

Details of First Stage

  1. Latent Phase: 0-3 cm dilation, contractions may occur every 3-30 minutes and last 30-40 seconds, often manageable at home.

  2. Active Phase: 4-7 cm dilation, contractions become more intense, every 2-5 minutes lasting 40-60 seconds; the mother may require continuous support.

  3. Transition Phase: 8-10 cm dilation, marked by intense contractions, occurring every 1.5-2 minutes lasting 60-90 seconds, often characterized by significant maternal fatigue and emotion.

Second Stage

  • From full dilation to delivery, contractions continue every 2-3 minutes lasting 40-60 seconds. Techniques for effective pushing include:

    • Closed Glottis: Holding breath during pushing.

    • Open Glottis: Controlled breathing throughout the contraction to aid progression.

Third Stage

  • Duration from the delivery of the infant to delivery of the placenta, typically lasting 5-10 minutes but can extend longer depending on various factors such as uterine tone and maternal effort.

Fourth Stage

  • Postpartum period: critical care for the mother, monitoring for complications such as bleeding and ensuring emotional support.

Vaginal Birth vs. Cesarean Birth

  • Vaginal Birth: Typically associated with shorter recovery times and fewer complications. Recommended unless specific contraindications exist.

  • Cesarean Birth: Ideal cesarean section rate is 10-15%. Common reasons include failure to progress, fetal distress, and a history of uterine surgery. Emphasis is placed on minimizing intervention and encouraging the presence of supportive persons during birth for a better experience.

Conclusion

Labor and delivery encompass complex physiological processes influenced by both maternal and fetal health, requiring adequate preparation and an understanding of the stages involved.