LABOR & DELIVERY Prof. Unn Hidle Updated Spring 2010

1. LABOR & DELIVERYProf. Unn HidleUpdated Spring 2010

2. Suggested audio-visual material: • Leopold’s Maneuver (Video) • Labor and Delivery: the LDR – Normal Vaginal Delivery (Video) • C-section (Video) • Electronic Fetal Monitoring (Video)

3. Suggested Websites: • International Cesarean Action Network (for information of c-sections, VBACs, etc.): • http://www.ican-online.org • To correct fetal positioning at home: • http://www.spinningbabies.com • Choices in Childbirth (this site has a lot of statistical information on NY state hospitals obstetrical interventions): • http://www.choicesinchildbirth.org

4. Critical factors in labor & birth • The passage • The fetus • The relationship between the passage and the fetus • The forces of labor • The psychosocial consideration

5. The Birth Passage The true pelvis is divided into 3 sections: - the inlet, the pelvic cavity (midpelvis), and the outlet The four classic types of pelvis are: gynecoid, android, anthropoid and platypelloid. The gynecoid, or female, pelvis is most common Size of the pelvis: Diameters of the pelvic inlet, midpelvis or pelvic cavity, and outlet Ability of the cervix to dilate and efface

6. Pelvic Types

7. The Fetus • Fetal head (size and presence of molding) • Fetal attitude • Fetal lie • Fetal presentation • Placenta (implantation site)

8. Fetal head • The fetal skull or cranium consists of the face, the base of the skull and the vault of the cranium or roof. • The bones of the face and cranial base are well fused and essentially fixed • Molding refers to the cranial bones overlapping under pressure during labor • Sutures of the fetal skull are membranous spaces between the cranial bones. • Fontanelles are the intersections of the cranial sutures. These sutures allow for molding of the fetal head.

10. Fontanelles • The anterior fontanelle is diamond shaped and measures about 2-3cm. It permits growth of the brain by remaining unossified for as long as 18 months. • The posterior fontanelle is much smaller and closes within 8-12 weeks after birth

11. Fontanelle

13. Fetal attitude • Fetal attitude is the relation of the fetal parts to one another. • The normal attitude of the fetus is one of moderate flexion of the head, flexion of the arms onto the chest, and flexion of the legs onto the abdomen

15. Fetal Lie • Fetal lie refers to the relationship of the cephalocaudal (spinal column) axis of the fetus to the cephalocaudal axis of the woman. • A longitudinal lie occurs when the cephalocaudal axis of the fetus is parallel to the woman’s spine • A transverse lie occurs when the cephalocaudal axis of the fetus is at a right angle to the woman’s spine

16. Fetal lie? Attitude?

17. Fetal lie? Attitude?

18. Fetal lie? Attitude?

19. Fetal Presentation • Fetal presentation is determined by fetal lie and by the body part of the fetus that enters the pelvic passage first, the presenting part • Fetal presentation may be cephalic (most common), breech, or shoulder • Breech and shoulder presentations are referred to as malpresentations as they are associated with difficulties during labor • Of note, some cephalic presentations are considered malpresentations, i.e. military or face. However, the overall cephalic category is the PREFERRED presentation.

20. Examples of presentations

21. Cephalic Presentationincludes all of the following: • 97% of births • Fetal head presents itself to the passage • “Subcategories” of cephalic presentation includes: • Vertex presentation: Occiput is the presenting part – most common type • Military presentation: The fetal head is neither flexed nor extended • Brow Presentation: The fetal head is partially extended • Face presentation: The fetal head is hyperextended

22. Breech Presentation • 3% of births • Sacrum is the landmark to be noted • Frank Breech: the fetal hips are flexed and the knees are extended. The buttocks of the fetus present to the maternal pelvis • Complete Breech: the fetal knees and hips are both flexed; the thighs are on the abdomen and the calves are on the posterior aspect of the thighs • Footling Breech: the fetal hips and legs are extended, and the feet of the fetus present to the maternal pelvis (single or double footling)

24. Shoulder Presentation • Also called a transverse lie • Most frequently, the shoulder is the presenting part and the acromion process (A) of the scapula is the landmark to be noted

25. Functional relationships of presenting part and passage

26. Engagement • Engagement of the presenting part occurs when the largest diameter of the presenting part reaches or passes through the pelvic inlet. • Engagement can be determined by vaginal, rectal examination or abdominal palpation • With abdominal palpation, if hands can pass between the fetal head and the pelvic inlet (converge), the fetus is not engaged (ballottment) • Usually, the point of engagement is station zero • Engagement confirms the adequacy of the pelvic inlet

27. Station • Station refers to the relationship of the presenting part to an imaginary line drawn between the ischial spines of the maternal pelvis. • The ischial spines as a landmark have been designated as zero station (the exact point of engagement) • If the presenting part is higher than the ischial spines, a negative number is assigned, noting cm above zero station • Positive numbers are used to indicate that the presenting part has passed the ischial spines • Station -5 is the pelvic inlet, and station +4 is the outlet (pelvic floor) • Station -4 means the presenting part is floating (ballottment)

32. Fetal Position • Fetal position refers to the relationship of a designated landmark on the presenting fetal part to the front, sides, or back of the maternal pelvis • The landmark on the fetal presenting part is related to 4 imaginary quadrants of the pelvis: left anterior (LA), right anterior (RA), left posterior (LP), and right posterior (RP)

33. The landmark chosen for vertex presentations is the occiput (O), and the landmark for face presentation is the mentum (M) • In breech presentations, the sacrum (S) is the designated landmark • In shoulder presentation, the acromion process (A) on the scapula is the landmark

34. TO COMBINE THE NOTATIONS: • Three notations are used to describe the fetal position: • Right (R) or left (L) side of the maternal pelvis • The landmark of the fetal presenting part: occiput (O), mentum (M), sacrum (S) or acromion process (A) • Anterior (A), posterior (P), or transverse (T), depending on whether the landmark is in the front, back, or side of the pelvis • Of note, the term dorsal (D) refers to fetal position in transverse lie, it refers to the fetal back

37. A few examples • Position: LOA = _________ • Lie: _____________ • Presentation: _____________ • Attitude: _______________

38. Position : RADP = ________ • Lie : __________________ • Presentation: _____________ • Attitude: ________________

39. Position: RMA = _________ • Lie: ____________________ • Presentation: _____________ • Attitude: _________________

40. Position: RSA = ___________ • Lie: __________________ • Presentation: ______________ • Attitude: ________________

41. How can nurses benefit from this knowledge?

42. Leopold’s maneuvers • Leopold’s maneuvers are a systematic way to evaluate the maternal abdomen • Examiner can determine fetal position and presentation

43. Leopold’s Maneuver

44. FETAL MONITOR

45. Fetal Heart Rate monitoring

46. Placement of FHR monitor

47. Assisting with external version of fetus

48. Electronic monitoring of contractions • Tocodynamometer or “TOCO” is an external monitoring device for uterine contractions • It is positioned against the fundus of the uterus and held in place with an elastic belt • The toco contains a flexible disk that responds to pressure • When the uterus contracts, the fundus tightens and the change in pressure against the toco is amplified and transmitted to the electronic fetal monitor

49. Fetal Heart Rate Monitoring • Tachycardia • Bradycardia • Variability: LTV versus STV • Accelerations • Decelerations: Early, Late & Variable

50. Fetal Heart Rate Monitoring • Baseline rate: • Refers to the average FHR observed during a 10-minute period of monitoring. • Normal range is 120-160 BPM • >160 BPM = tachycardia • <120 BPM = bradycardia