Preterm Labor and Delivery

1. Preterm Labor and Delivery

2. Statistics • 12.8% of all deliveries in the U.S. in 2006 • These preemies comprise 80% of all perinatal deaths in the U.S. • Preterm birth is the leading cause of infant mortality in Ohio. •   Among states, we rank 35th in infant mortality and 31st in prematurity

3. Economic Impact • Average hospital cost for a 25 weeker to discharge is $203,000 • 32 weeks almost $19,000. more than 38 weeks • Even at 36 weeks there is an increased cost of $1700 more than delivery at 37 weeks

4. Ethnic disparities • 17.9% of all black births • 13.7 of all Native American Indian

5. Causes • Cause remains greatly unknown • What we know and what we don’t know

6. Theories There is compelling evidence to support four major pathways: • Stress • Placental abruption • Infection • Uterine distension

7. Further study needed to determine significance of: • Link to poor dental health • Link to intention of pregnancy • Link to racial discrimination and associated stress

8. Epidemiologic Approach • Based on placental histology and placental microbiology • Disorders leading to preterm delivery can be separated into 2 groups:

9. Epidemiologic Approach • Those associated with intrauterine inflammation, Chorioamnionitis, placental microbe recovery • PROM • Placental abruption • Cervical insufficiency • Preterm labor

10. Epidemiologic Approach • Those associated with aberrations of placentation • Preeclampsia • Intrauterine growth restriction Mcelrath, et al (2008) Pregnancy disorders that lead to delivery before the 28th week of gestation: An epidemiologic approach to classification. American Journal of Epidemiology. 168 (9)

11. Risk Factors • History of previous preterm delivery is the #1 risk factor. • Previous cervical procedures: cone biopsy and LEEP • Uterine anomalies • Multiple gestation • Urinary tract infections • Pregnancy with the past 12 months

12. The Preterm Prediction Study • Positive Fetal fibronectin and short cervical length are good indicators for predicting preterm delivery • Newman, Goldenberg, Iams, et al (2008) Preterm prediction study: Comparison of the Cervical score and Bishop score for prediction of spontaneous preterm delivery. Obstetrics & Gynecology. 112 (3), 508-515.

13. Bio-Chemical predictors • Fetal Fibronectin is a glycoprotein • Should not be detectable between 22-35 weeks gestation

14. Negative Fetal Fibronectin • Negative Ffn results are most useful • 99.2% negative predictive value • Highly unlikely that preterm labor will occur within 14 days.

15. Positive Fetal Fibronectin • Positive predictive value: not so good • Only 65% with positive Ffn will have a preterm delivery

16. Collecting Ffn specimen

17. For Accurate Patient Results • For accurate patient results, please ensure that you follow these specimen collection instructions. • The specimen should be collected prior to a digital cervical exam, collection of culture specimens, or vaginal probe ultrasound exams. • Do not contaminate the swab or specimen with lubricants, soaps, disinfectants, or creams. • Do not collect specimen if patients have had sexual intercourse within 24 hours prior to sampling; moderate or gross vaginal bleeding; advanced cervical dilation (3 cm or greater); rupture of membranes; gestational age <22 weeks or >35 weeks; or suspected or known placental abruption or placenta previa.

18. Biophysical Predictors • Cervical length less than 20 mm per transvaginal ultrasound • Cervical score less than 1.5 per digital cervical exam • Cervical score = Cervical length (cm) minus Cervical Dilation (cm) at the internal os

19. Cervical score • Uses digital cervical examination for measurement • Eliminates cost and logistical difficulties of serial transvaginal ultrasound

21. ACOG Diagnosis • Regular contractions that occur before 37 weeks gestation and are associated with changes in the cervix. • (No proven cause/effect)

22. How to manage • Hydration • Bed rest • Little evidence to demonstrate effectiveness

23. Pharmacologic management • Tocolytics have failed to demonstrate effectiveness in preventing preterm labor • Some delay delivery for 48 hours • Buying steroid time

24. Beta-adrenergics- terbutaline and ritodrine • Beta-adrenergics- terbutaline and ritodrine • Stimulate beta2-adrenergic receptors relaxing smooth muscle • Not shown to reduce preterm birth • Substantial maternal adverse effects: bronchospasm, HTN, arrhythmias, pulmonary edema, hyperglycemia, seizures • Neonatal effects: fetal tachycardia, neonatal hypoglycemia (reactive)

25. Calcium Channel blockers- Nifedipine • Calcium Channel blockers- Nifedipine • Inhibits Calcium ion influx into smooth muscle: • Demonstrates effectiveness in delaying delivery • Does not prevent preterm delivery • Adverse reactions: CHF, pulmonary edema, arrhythmia, severe hypotension • Common S/E: headache, dizziness, flushing, fatigue, weakness, transient hypotension

26. Prostaglandin antagonists- Indocin • Prostaglandin antagonists- Indocin • NSAID: exact action unknown, but reduces prostaglandin synthesis • Second line drug in pregnancy less than 32 weeks. • May increase risk of serious and potentially fatal CV thrombotic events • Serious GI events including bleeding

27. Indocin- fetal adverse side effects • Contraindicated after 32 weeks • Can cause premature closure of the ductus arteriosis in the fetus • Increase risk of necrotizing enterocolitis in the premature neonate • Increase risk of Periventricular leukomalacia (form of brain injury that can lead to CP)

28. Magnesium Sulfate • CNS depressant • Serious reactions: cardiovascular collapse, respiratory paralysis, hypothermia, depressed cardiac function and pulmonary edema • Common S/E: depressed DTR, hypotension, flushing, drowsiness, visual changes • *Important to maintain urinary output to prevent toxicity • Little evidence exist to support its use as a tocolytic

29. Magnesium sulfate may decrease risk of IVH • Preliminary studies suggests antepartum administration of Magnesium sulfate may have a neuroprotective effect on premature neonates. • Decreasing the number and severity of intraventricular hemorrhage in preterm neonates and thereby reducing CP • Further research needed

30. When is tocolysis contraindicated? • Presence of infection- chorioamnionitis • Suspected placental abruption • Pregnancy Induced Hypertension

31. Antibiotics • May be indicated in PTL to treat infection as a causative factor. • Bacteruria • PROM • * Should not use tocolytics in the presence of infection

32. Management Goals • Focus is on early identification and prevention • Administration of corticosteroids to enhance fetal lung maturity • And delivery in a site capable of caring for the special needs of the premature neonate

33. Fetal Lung Maturity • Corticosteroids • Typically Betamethasone 12 mg IM dose x 2. • 12 mg then repeat in 24 hours • Make sure neonatal knows: dates important

34. Prevention • 17 P Alpha Hydroxy-Progesterone Caproate • There is sufficient evidence to support the administration of progesterone 17 P (injectable form) women with singleton pregnancy and: • a history of preterm birth (< 37 weeks) due to spontaneous onset of labor or SROM • Women with short cervix

35. 17 P • Weekly injections start between 16-20 weeks and continue until 37 weeks. • Reduced the risk of recurrent preterm birth by as much as 33% over the control group (March of Dimes)

36. Ongoing studies underway with regards to multiple gestations and progesterone vaginal cream

37. Prevention • Education: Information about pre-maturity, signs/symptoms, fetal development, hydration, public awareness

38. Warning Signs • More than 6 UC’s per hour • Tightening or “balling up” of abdomen (Avoid terminology like “Braxton-Hicks”) • Menstrual-like cramps • Back-pain • Pelvic pressure • Intestinal cramps, gas pains, flu • Increase or change in vaginal discharge • General feeling that something is not right

39. Prevention • Preconception health: smoking cessation #1, substance abuse, nutrition, folic acid, managing chronic illness ie: Diabetes, HTN, obesity, asthma

40. Health Promotion while pregnant • Good nutrition • Prenatal vitamins-folic acid • Adequate weight gain • Exercise • Decreasing stress • Avoid occupational exposures • Treatment for sub-clinical infections

41. Prevention • Stress the importance of regular prenatal visits • Refer to appropriate provider and regional perinatal center based on risk of preterm birth

42. Prevention • Stress reduction: coping skills, social networking, case management, referral services (nutrition, counseling, housing issues) • Psychological support: nurse/patient relationship, group work, home visits, telephone counseling

43. Iatrogenic prematurity • Iatrogenic disorder-An abnormal mental or physical condition induced in a patient by effects of treatment by a physician or surgeon. Term implies that such effects could have been avoided by proper and judicious care on the part of the physician.

44. Timing of elective delivery • Late preterm ( 34 0/7- 36 6/7 weeks gestation) • Early term (37 0/7-38 6/7 weeks gestation)

45. Standards, Guidelines, and Recommendations • Avoid elective induction of labor and elective cesarean birth before 39 weeks of gestation (ACOG, 1999) • Assess fetal lung maturity if there is any question of gestational age before 39 weeks of gestation prior to elective or repeat cesarean birth (AAP & ACOG, 2002)

46. OPQC- Ohio Perinatal Quality Collaborative • The mission of OPQC (Ohio Perinatal Quality Collaborative) is to decrease preterm birth and associated infant morbidities in the State of Ohio. The AIM this year is to reduce by 60% the number of women in Ohio of 36.0 to 38.6 weeks gestation for whom initiation of labor or cesarean section is done in absence of appropriate medical or obstetric indication.

48. Patient Education resources • March of Dimes • AWHONN

49. What about the post-partum period? • Women treated with bed rest experienced cardiopulmonary and musculoskeletal deconditioning • muscle atrophy, muscle soreness of back, legs and knees • Shortness of breath on exertion • Difficulties with gait, negotiating stairs, and transferring to chair • Depression • Financial difficulties (loss of income/insurance)

50. Maternal complications • Breastfeeding problems/Enhance milk production/ early breast pump • Interrupted process of bonding • Stress/Anxiety/feeling hopeless • Sequelae of extended bed rest • Disruption of family unit • Post-partum depression