Labor and Delivery

1. Labor and Delivery CAPT Mike Hughey, MC, USNR

2. Labor • Regular, frequent, leading to progressive cervical effacement and dilatation • Braxton-Hicks contractions • May be painful and regular, but usually are not • Do not lead to cervical change • Labor diagnosis usually made in retrospect. • Cause of labor is unknown

3. Latent Phase Labor • <4 cm dilated • Contractions may or may not be painful • Dilate very slowly • Can talk or laugh through contractions • May last days or longer • May be treated with sedation, hydration, ambulation, rest, or pitocin

4. Active Phase Labor • At least 4 cm dilated • Regular, frequent, usually painful contractions • Dilate at least 1.2-1.5 cm/hr • Are not comfortable with talking or laughing during their contractions

5. Progress of Labor • Lasts about 12-14 hours (first baby) • Lasts about 6-8 hours (subsequent babies) • Considerable variation. • Effacement (thinning) • Dilatation (opening) • Descent (progress through the birth canal)

6. Descent • Fetal head descends through the birth canal • Defined relative to the ischial spines • 0 station = top of head at the spines (fully engaged) • +2 station = 2 cm past (below) the ischial spines

7. Cardinal Movements of Labor • Engagement (0 Station) • Descent • Flexion (fetal head flexed against the chest) • Internal rotation (fetal head rotates from transverse to anterior • Extension (head extends with crowning) • External rotation (head returns to its’ transverse orientation) • Expulsion (shoulders and torso of the baby are delivered)

8. Watch a Delivery

9. Placental Separation • Signs of separation: • Increased bleeding • Lengthening of the cord • Uterus rises, becoming globular instead of discoid • Uterus enlarges, approaching the umbilicus • Normally separates within a few minutes after delivery

10. Initial Labor Management • Risk assessment • Contractions: frequency, duration, onset • Membranes: Ruptured, intact • Status of cervix: dilatation, effacement, station • Position of the fetus: vertex, transverse lie, breech • Fetal status: fetal heart rate, EFM

11. Cervix • Dilatation: How far has the cervix opened (in cm) • Effacement: How thin is the cervix (in cm or %)

12. Status of Membranes • Nitrazine paper turns blue in the presence of alkaline amniotic fluid (“nitrazine positive”) • Vaginal secretions are nitrazine negative (yellow) because of their acidity • Pooling of amniotic fluid in the vaginal vault is a reliable sign

13. Orientation of Fetus • Vertex, breech or transverse lie • Palpate vaginally • Leopold’s Maneuvers

14. Management of Early Labor • Ambulation OK with intact membranes • If in bed, lie on one side or the other…not flat on her back • Check vital signs every 4 hours • NPO except ice chips or small sips of water

15. Monitor the Fetal Heart • During early labor, for low risk patients, note the fetal heart rate every 1-2 hours. • During active labor, evaluate the fetal heart every 30 minutes • Normal FHR is 120-160 BPM • Persistent tachycardia (>160) or bradycardia (<120, particularly <100) is of concern

16. Electronic Fetal Monitors • Continuously records the instantaneous fetal heart rate and uterine contractions • Patterns are of clinical significance. • Use in high-risk patients. • Use in low-risk patients optional

17. Normal Patterns • Normal rate • Short term variability (3-5 BPM) • Long term variability (15 BPM above baseline, lasting 10-20 seconds or longer) • Contractions every 2-3 minutes, lasting about 60 seconds

18. Tachycardia • >160 BPM • Most are not suggestive of fetal jeopardy • Associated with: • Fever, Chorioamnionitis • Maternal hypothyroidism • Drugs (tocolytics, etc.) • Fetal hypoxia • Fetal anemia • Fetal arrythmia

19. Bradycardia • Sustained <120 BPM • Most are caused by increased in vagal tone • Mild bradycardia (80-90) with retention of variability is common during 2nd stage of labor • <80 BPM with loss of BTBV may indicate fetal distress

20. Late Decelerations • Repetive, non-remediable slowings of the fetal heartbeat toward the end of the contraction cycle • Reflect utero-placental insufficiency

21. Early Decelerations • Periodic slowing of the FHR, synchronized with contractions • Rarely more than 20-30 BPM below the baseline • Innocent • Associated with fetal head compression

22. Variable Decelerations • Variable in onset, duration and depth • May occur with contractions or between them • Sudden onset/recovery • Increased vagal tone, usually due to some degree of cord compression

23. Severe Variable Decelerations • Below 60 BPM for at least 60 seconds • If persistent, can be threatening to fetal well-being, with progressive acidosis

24. Prolonged Decelerations • Last > 60 seconds • Occur in isolation • Associated with: • Maternal hypotension • Epidural • Paracervical block • Tetanic contractions • Umbilical cord prolapse

25. Pain Relief • Narcotics • Continuous Lumbar Epidural • Paracervical Block • 50/50 nitrous/oxygen • Psychoprophylaxis (Lamaze breathing) • Hypnosis

26. Anesthesia During Delivery • Local • Pudendal Block • Epidural • Caudal • Spinal • 50/50 nitrous/oxygen

27. Episiotomy • Avoids lacerations • Provides more room for obstetrical maneuvers • Shortens the 2nd Stage Labor • Midline associated with greater risk of rectal lacerations, but heals faster • Many women don’t need them.

28. Clamp and Cut the Cord • Clamp about an inch from the baby’s abdomen • Use any available instruments or usable material • Check the cord for 3-vessels, 2 small arteries and one larger vein

29. Inspect the Placenta • Make sure it is complete • Look for missing pieces • Look for malformations • Look for areas of adherent blood clot