Fetal Positioning and Stages of Labor

Fetal Positioning

• Fetal malposition may occur due to oligohydramnios, reducing fetal movement space, or neurologic abnormalities leading to spasticity.
• Fetal lie describes how the long axis of the fetus aligns with the long axis of the mother's body.
• Longitudinal lie can be cephalic (head first) or breech (feet or buttocks first)
• Cephalic presentation occurs in approximately 96% of births, with the vertex being the ideal presenting part for effective cervical molding.
• Caput succedaneum, an edema on the fetal skull, can form during labor and helps identify the presenting part of the fetus.
• Breech presentation involves the buttocks or feet contacting the cervix.
• Complete Breech: Thighs are flexed; both buttocks and feet present.

Stages of Labor

• Second Stage: Full dilatation and cervical effacement to infant birth
  • Contractions: 2-3 minutes apart, lasting 60-75 seconds, with strong intensity.
  • Pushing sensations become uncontrollable and may lead to momentary nausea or vomiting.
  • As the fetal head descends, the perineum bulges and appears tense, and the anus may evert.
  • Crowning occurs when the fetal scalp appears at the vaginal opening and increases in size.
• Third Stage: Placental Stage
  • Begins with infant birth and ends with placental delivery.
  • Two phases: Placental separation and placental expulsion.
  • Placental separation causes bleeding on the maternal surface, aiding further separation from the attachment site.
  • Patients may wish to take home the placenta for cultural reasons.
  • Cord blood samples can be taken for future stem cell transplantation.

Maternal Physiological Effects of Labor

• Cardiovascular System:
  • Cardiac output increases significantly.
  • Blood pressure may rise due to contractions and pain response.
  • Epidural anesthesia can cause hypotension.
  • Monitor for hemorrhage and signs of pathology.
• Hematopoietic System:
  • White blood cell count rises during labor.
  • Monitor for signs of infection.
• Respiratory System:
  • Increased respiratory rate due to cardiovascular activity.
  • Total oxygen needs double during the second stage of labor.
  • Monitor for hyperventilation.
• Temperature Regulation System:
  • Body temperature may increase slightly.
  • Diaphoresis (sweating) occurs to help with cooling.
  • Monitor for signs of infection.
• Fluid Balance:
  • Insensible water loss increases.
  • Encourage fluid intake.
• Urinary System:
  • Fetal head pressure reduces bladder tone.
  • Encourage voiding every 2 hours.
• Musculoskeletal System:
  • Relaxin secreted during pregnancy increases joint flexibility, allowing the pelvic joints to open during labor.
  • Monitor for appropriate mobility and fall risks.
• GI System:
  • Blood shunts to vital organs, reducing GI activity.
  • Follow hospital protocols regarding oral intake.

Medical History Assessment

• Past Health History:
  • Document any previous surgeries, heart diseases, diabetes, anemia, tuberculosis, kidney disease, hypertension, or sexually transmitted infections to ensure safe birthing practices.
  • Assess risk for drug abuse or HIV exposure.
• Family Medical History:
  • Inquire about inherited conditions such as cognitive challenges, heart disease, blood dyscrasia, diabetes, kidney disease, allergies, seizures, hearing loss, or malignant hyperthermia.

Physical Exam

• Overall Appearance:
  • Assess for tiredness, paleness, illness, fear, edema, dehydration, and open lesions.
• Palpate neck lymph nodes for signs of respiratory infection.
• Inspect mucous membranes and conjunctiva for pallor indicating anemia.
• Examine teeth for caries or abscesses.
• Inspect lips for herpes lesions.
• Adapt further examination techniques based on labor stage and progression.