1 / 73

Pregnancy, Labor, and Delivery

Pregnancy, Labor, and Delivery. Calla Holmgren, MD Department of Obstetrics & Gynecology University of Washington. Objectives. Review normal physiologic changes in pregnancy Discuss historical context of labor and delivery Review normal and abnormal labor

Download Presentation

Pregnancy, Labor, and Delivery

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.


Presentation Transcript

  1. Pregnancy, Labor, and Delivery Calla Holmgren, MD Department of Obstetrics & Gynecology University of Washington

  2. Objectives • Review normal physiologic changes in pregnancy • Discuss historical context of labor and delivery • Review normal and abnormal labor • Evaluate interventions for abnormal labor

  3. Cardiovascular Changes •  Major hemodynamic changes induced by pregnancy include • Increase in cardiac output • Sodium and water retention leading to blood volume expansion • Increase until 34 weeks gestation • Reductions in systemic vascular resistance and systemic blood pressure

  4. Cardiovascular Changes • These changes begin early in pregnancy • Reach their peak during the second trimester, and then remain relatively constant until delivery • They contribute to optimal growth and development of the fetus • Help to protect the mother from the risks of delivery, such as hemorrhage

  5. Hemodynamic changes in normal pregnancy

  6. Pulmonary Changes • Marked changes in respiratory system during pregnancy • These can be measured using direct spirometry • Vital Capacity- increased by 100-200 mL • Inspiratory Capacity- increased by 300 mL • Expiratory Reserve Volume- decreases • Residual Volume- Decreases • Functional Residual Capacity- reduced • Tidal Volume- increases from 500 to 700 mL • Minute Ventilation- increases 40%

  7. Pulmonary Changes • The total of these changes is increased ventilation • Due to deeper but not more frequent breathing • Most likely used to help supply increased basal oxygen consumption

  8. Gastrointestinal Changes • Pregnancy has little, if any, effect on gastrointestinal secretion or absorption • But it has a major effect on gastrointestinal motility • Hormones • Enlarging uterus

  9. Endocrine Changes • Endocrine adaptations to the pregnant state begin just after conception and evolve through delivery • They almost completely revert back to the nonpregnant state over a period of weeks • Virtually all endocrine glands are affected

  10. Endocrine Changes • Maternal endocrine adaptations to pregnancy • Hypothalamus • Pituitary • Parathyroid • Thyroid • Adrenal glands • Ovary

  11. Musculoskeletal Changes • Anatomic and physiologic changes occurring during pregnancy have the potential to affect the musculoskeletal system at rest and during exercise • Weight gain • Shift in center of gravity • Increased ligamentous laxity

  12. Musculoskeletal Changes • Weight gain • Typically 11.5 to 16 kg • May double the forces across joints compared to nonpregnant forces • Shift in center of gravity • Shifted forward • A posture of increased lumbar lordosis • Back pain • Loss of balance; increased fall risk • Increased ligamentous laxity • Related to the effects of estrogen and relaxin

  13. Prenatal Care • The major goal of prenatal care is to ensure the birth of a healthy baby with minimal risk for the mother • Early, accurate estimation of gestational age • Identification of the patient at risk for complications • Ongoing evaluation of the health status of both mother and fetus • Anticipation of problems and intervention, if possible, to prevent or minimize morbidity • Patient education and communication

  14. Prenatal Care • History and physical • Laboratory tests • Ultrasound examination • Patient education • Preparation for labor and delivery

  15. History and Physical • History • Personal and demographic information • Past obstetrical history • Personal and family medical history • Past surgical history • Genetic history • Menstrual and gynecological history • Current pregnancy history • Psychosocial information • Physical • Special attention to uterine size and shape and evaluation of the adnexa • Fetal heart tones • Doppler: 9 to 12 weeks of gestation • Transvaginal ultrasound 5.5 to 6.0 weeks

  16. Laboratory Assessment • Hematocrit or hemoglobin to detect anemia • Cervical cytology • Blood type and screen • Rubella immunity testing • Urinary infection testing • Syphilis testing • Hepatitis B antigen testing • Gonorrhea and Chlamydia testing • HIV testing • Thyroid disorders? • Heritable disorders • Genetic screening

  17. Ultrasound Examination • First trimester • Accurately dates pregnancy • Assessment of fetal well being • 18-20 weeks • Anatomic survey • Late second/third trimester • Growth • Fetal well being

  18. Patient Education • Seat belts • Vitamins, nutrition, and weight gain • Substance use  • Infection precautions • Work  • Exercise  • Birth defects and genetic issues • Use of medications • Airline travel

  19. The History of Childbirth • Historically, pregnancy has been managed by women (family, friends, midwife) with delivery in the home • In the 14th-18th Centuries medicine was dominated by men and the Church

  20. History of Childbirth • Industrialization of America brought mothers from their homes to hospitals (“lying-in”) for birth • Obstetrics was then performed by surgeons (not midwives)

  21. Why do we need to know about labor? • Four million births per year in the United States alone • In underdeveloped nations – lack of skilled attendants • Natural process with modernization

  22. Maternal Mortality Ratio (WHO, 2002)

  23. Maternal Mortality(Grady Memorial Hospital, GA)

  24. Maternal Mortality(GMH, 1949-2000)

  25. What is labor? • Labor = the act of uterine contractions combined with cervical change • Fetus is gradually pushed through the birth canal (consisting of the cervix, vagina and perineum) • Placenta is extruded and uterus involutes

  26. What is labor?

  27. What is labor?

  28. What starts labor? • An intricate and baffling association between fetus and mother exist • Several components are known, but many are not – extrapolated from animals • Involves hormonal communications between mother and fetus • In other words – we can speculate but we’re not quite sure!

  29. Induction of Labor • Need to have a reason! • Maternal indications • Fetal indications • Need to have a plan! • Favorable cervix? • No? Cervical ripening • Yes? Pitocin

  30. Bishop Score

  31. Cervical Ripening • Mechanical • Stripping (or sweeping) of the fetal membranes • Placement of hygroscopic dilators within the endocervical canal • Insertion of a balloon catheter above the internal cervical os (with or without infusion of extra-amniotic saline) • Pharmacologic • Prostaglandins • Prostaglandin E2-cervidil • Prostaglandin E1-misoprostil

  32. After the initiation of labor… • Factors responsible for the ongoing labor process include: • Oxytocin • Prostaglandins (PGF2-alpha, thromboxane, PGE1,E3) • Endothelin (by receptor-PLC coupling via nifedipine sensitive channels) • Epidermal Growth Factor

  33. How does the uterus contract? • The uterus is made from a weave of smooth muscle (myometrium) covered by a smooth cellular surface (serosa) – all formed by the joining of the two original mullerian horns • The cavity is hollow and lined by vascular/stromal bed that is responsive to hormonal stimulation (i.e. menstrual cycle)

  34. Structure of the uterus

  35. What does the myometrium need to contract? • CALCIUM! • Calcium channels allow influx which through a cascade of events activates myosin • Smaller calcium supply comes from other organelles (i.e.. Sarcoplasmic reticulum) • These all play a part in how we can manipulate labor!

  36. The Cardinal Movements of Labor

  37. Stages of Labor • First stage – Latent and active labor • Second stage – Descent with pushing to delivery of baby • Third stage – Delivery of placenta • Fourth stage – involution of the uterus

  38. Stages of Labor

  39. Stages of Labor • Stage 1 (Latent Phase) • Uterus and cervix prepare for active labor • Dilatation up to 4 cm • Variable length of time

  40. Stages of Labor • Stage 1 • The “Active” Phase – rapid cervical dilatation from 4 centimeters to 10 centimeters (or complete dilatation). Varies for nulliparous vs. multiparous patients • Nulliparous – 1.2 cm/hr • Multiparous – 1.5 cm/hr

  41. Stages of Labor • Stage 2 “Pushing” • Starts from complete dilatation to delivery of the fetus • Variable depending on parity maternal forces • Fetus has to make it’s way through the curves of the pelvis

  42. Third Stage of Labor • Stage 3 • From delivery of the fetus to delivery of the placenta • Variable amounts of time for placental extrusion but generally within the first 20-30 minutes • Medications can be used to augment placenta delivery and post-partum bleeding

  43. Fourth Stage of Labor • Stage 4 • Immediate period after placental delivery • Uterus contracts to close off venous sinuses and slow bleeding • Watch for signs of post-partum hemorrhage

  44. When is labor not progressing?

  45. Fetal causes of dystocia • Breech – presenting parts not optimal • Macrosomia – too big! • Occiput posterior – fetus is facing “sunnyside up” (face up) • Malpresentation – fetal head is not perfectly flexed • Compound presentation – two parts presenting • Congenital abnormalities obstructed in the birth canal

  46. Breech Presentation • Non-vertex presenting part – Buttocks! • Occurs in about 3-5% of term deliveries • Forms of breech presentation include complete, footling, and frank breech

  47. Breech presentation • Look for possible causes (large baby, no fluid, birth defects, uterine anomalies) • Risks of labor from breech presentations include fetal injury, cord prolapse, entrapment, maternal injury • Delivery options include vaginal breech delivery, external cephalic version (ECV), elective cesarean section

  48. Occiput posterior (OP) presentation • Approximately 10% of deliveries • Face is looking up towards the ceiling versus the floor • Fetus must perform opposite flexion/extension maneuvers to navigate the birth canal

  49. OP Presentations • What can we do about OP presentations? • Leave it alone – babies can deliver from OP, ROP and LOP presentations (back labor!) • Rotate the fetal head – manually or with forceps • Change labor positions for the mother such as knee-chest • Offer regional anesthesia – allows for pelvic muscle relaxation • If labor arrests - cesarean

  50. Malpresentation • Occurs when the bony parietal bones of the fetus are not the presenting. These include: • Face presentation 0.1-0.2% of all deliveries (head is hyper-extended) • Let nature work its magic – they usually deliver vaginally • Do not try to correct • Babies can have edematous faces, they resolve

More Related