Preterm Labor Assessment: An Evidence Based Toolkit Herman L. Hedriana, M.D. Sac MFM Medical Group Inc. Associate Clinical Professor in Ob/Gyn UC Davis School of Medicine Mary Campbell Bliss, RN, MS, CNS Perinatal Clinical Nurse Specialist Sutter Medical Center, Sacramento

Sources: National Center of Health Statistic, final natality data Retrieved Sept 2005 from Preterm Labor and Delivery (<37 Weeks) Preterm Labor 800,000 (1 in 5) pregnant women in US exhibit signs and symptoms of preterm labor 70% of women identified as “high risk” deliver at term Preterm Delivery >480,000 (12.3%) preterm births in 2003 Single largest cause of perinatal mortality and morbidity

Preterm Delivery Rates in the US 27% increase in the past 20 years Healthy People 2010 and March of Dimes goal is to reduce the rate to 7.6% by 2010 Leading cause of neonatal morbidity and mortality

Preterm Birth Rates in Multiples Multiple births increased from 2.4% in 1992 to 3.3% in 2002 At least half of all twins and >90% of higher order multiples deliver preterm The proportion of multiple preterm births increased 40% from 11.7% in 1992 to 16.4% in 2002 Rate /1000 live births Multiple Birth Ratios US,

Preterm Labor ICD-9: Acute Disease Specific acute treatment No effective prophylactic medication High recurrence rate Multiple triggering factors

Previous Pregnancies & Risk of Preterm Delivery FirstSecondSubsequent PTD Term5% Preterm15% TermPreterm24% Preterm 33% Carr-Hill; Kristensen et al.

Diagnosis of Preterm Labor Gestational age weeks Documented regular UC ≥6/hour AND At least one of the following: Rupture of membranes Cervical change Cervix 2 cm dilated or 80% effaced

National Economic Burden of Preterm Labor Hospitalization Discharge undelivered: $360,000,000 All admissions: $820,000,000 No change in the preterm delivery rate Increasing perinatal morbidity Nicholson et al. Obstet Gynecol 2000;96:95

What Women Know Re: Prematurity March of Dimes survey of 600 pregnant women Not viewed as public health issue Not seen as serious problem Seen as relatively uncommon Not see themselves at risk for preterm birth Worry about their own unhealthy behaviors Green, et al, Contemporary OB/GYN, 48(1), 2003.

What Women Know Re: Prematurity (con’t) 50% felt they knew signs/symptoms of preterm labor Amniotic fluid leaks and contractions best known Then bleeding, cramps, backache Most call physician if experiencing preterm labor Green, et al., Contemporary OB/GYN, 48(1), 2003

California March of Dimes Prematurity Prevention Initiative Grant to Sutter Medical Center, Sacramento Evidence based protocol for symptomatic women To establish a uniform diagnosis of PTL To guide assessment and diagnosis of PTL To avoid unnecessary hospitalizations and treatments To decrease use of scarce nursing/hospital resources

California Maternity Hospitals 285 hospitals and birth centers Provide all levels of care Goal of the grant: One standard assessment for symptomatic PTL patients

Preterm Labor Practice Assessment Prior to development of toolkit: Collected PTL protocols from Northern CA hospitals Developed grids with urban/rural and NICU/no NICU groupings Analyzed for commonalities/differences Identified research articles for review

Preterm Protocol Findings Consistent in some areas Electronic fetal monitoring MD notification Review of prenatal record/patient history Wide variation in other areas Definition of preterm labor Use of fetal fibronectin Sterile speculum exams/vaginal exams Disposition choices/criteria

Preterm Labor Diagnosis Reviewed current research and relevance to the diagnosis of preterm labor: Uterine contractions Fetal fibronectin Cervical length Initial goal: Sensitivity of the test Goal of evaluation: Specificity of the test

Labor Pain Persistent uterine contractions accompanied by dilation and/or effacement of the cervix detected by digital examination Gonik and Creasy AJOG 1986:154;3 Perceived contractions painful or painless but persistent Pelvic pressure, increased vaginal discharge, backache, menstrual-like cramps All found in term labor Poor sensitivity and specificity Likelihood in 7-14 days

Uterine Contractions/PTD Risk 306 women with hx of PTD or 2 nd trimester bleeding 11 sites – from Monitored contraction 2X/day = 39,908 hours Assessed fFN, Bishop scores, digital exams, and cervical length Freq. of cont. higher in PM/evening hours with increasing gestation. Iams, J.D. et al. 2002

Uterine Contractions/ PTD Risk Significant related to PTD, BUT low sensitivity and low positive predictive value for asymptomatic women Conclusion: Increased contractions for any individual woman is more likely to reflect advancing gestation and diurnal variation than occult preterm labor Iams, J.D. et al. Frequency of Uterine Contractions and the Risk of Spontaneous Preterm Delivery. N Eng J Med 2002, 346:250-5.

Frequency of Uterine Contractions 4 contractions or more Low probability of preterm birth in 7-14 days Degree of pain is irrelevant Initiating treatment results in unnecessary exposure to tocolytics Hueston BJ Obstet Gynecol 1998;92:38 Iams et al NEJM 2002;346:250 Gestational Age (weeks) Sensitivity Positive Predictive Value %25% %23%

Digital Examination 3 cm/80%/vtx/0/SROM/BRB Best clinical sign 95% PPV in 7-14 days Hueston BJ Obstet Gynecol 1998;92:38 Assess the structure of the external os No clinical value if cervix is < 2cm or < 80% effaced Iams et al Obstet Gynecol 1994;84:40

Fetal Fibronectin (fFN) Protein related to cellular cohesiveness High levels at membrane-decidua interface Disruption of interface releases fFN Protein detected via immunoassay Positive test > 50 ng/ml

Amnion Chorion Fetal Fibronectin Decidua Fetal Fibronectin

Fetal Fibronectin vs Gestational Age Fetal Fibronectin (ng/mL) Gestational Age (weeks) Clinically Relevant Time Frame (22-35 weeks) Source: Adapted from Garite TJ et al. Contemp Obstet Gynecol. 1996;41: ng/mL Cutoff Level

Clinical Value of fFN Cervix < 3cm, <80% effaced & IBOW Sensitivity is 90% Excellent negative predictive value within 7-14 days % (24 – 28 weeks) 95% (>28 - <34 weeks) Poor positive predictive value (18-20%) Iams et al AJOG 1995;173:141, Peaceman et al AJOG 1997;177:13, Leitich et al AJOG 199;180:1169

A Negative fFN Test Based on the high negative predictive value (NPV) of fFN, decreased levels of intervention are possible: Reassurance and education for patient Ongoing prenatal surveillance Avoidance of tocolytic agents Less disruption of patient’s lifestyle Continue care of immediate family Continue work Normal ADLs

fFN in Clinical Care Algorithms Not for establishing diagnosis Exclusion (NPV) is its strength Included in algorithms to exclude the likelihood of preterm labor Must be rapidly available Commitment to act on the result by not starting tocolytics 3 published studies demonstrating possible impact on cost savings

fFN in Clinical Care Algorithms In a tertiary setting: fewer admission for PTL, shorter hospital stay, less tocolytic exposure, no adverse neonatal outcome $486,000 saved in charges Joffe et al AJOG 1999:180;581 In community hospital setting: no benefit in > 3 cm cervical dilation; 90% reduction of transfers to tertiary facility Giles et al AJOG 2000:182;439 Savings do not show in cost analysis models in a large teaching facility (Bethesda) Sullivan et al JMFM 2001:10;1

Length of Cervix and the Risk of Preterm 24 wks Cx (mm)RR

Reliability of Cervical Length Consistent images in more than 95% of patients regardless of habitus and order of multiples Strict adherence to criteria Superior Positive Predictive Value (PPV) to digital exam Cervical length of 30 mm or more have very high Negative Predictive Value

Combining Cervical Length and Fetal Fibronectin Improves accuracy of diagnosis Goldenberg et al AJPH 1998:88;233, Rizzo et al AJOG 1996:175;1146 In diagnosis, combined is not superior to either one alone. Rozenberg et al AJOG 1997:176;196 Strength consistently with exclusion Goldenberg et al AJPH 1998:88;233

Toolkit Definition of Preterm Labor Persistent uterine contractions Objective documentation of cervical change Dilated to > 2 cm or 80% effaced Positive biochemical marker

Preterm Labor Taskforce Consensus Decisions Labor is consistent contractions with cervical change Rapid fFN chosen as screening test for preterm labor in symptomatic patients Transvaginal ultrasound for cervical length is used as an adjunct of fFN Decision to admit, discharge, transport to be made within 4 hours

PTL Assessment Toolkit Contents PTL Care/Disposition Protocol/Algorithm PTL Assessment Pre-Printed Orders PTL Home Care Instructions PTL Patient Education Procedures (Speculum, GBS, Ferning) Competencies PTL Power Point Presentations

Preterm Labor Care/Disposition Protocol Confidence that uterine contractions alone DO NOT mean labor Contains a logical sequence of events Disposes of clinical concerns Should allow for a decision within 4 hours of admission

Evaluation of Symptomatic Preterm Labor Review of history Fetal heart and contraction monitoring Cervical examination - look for best clinical sign Severity of symptoms bears very little to clinical significance Do not initiate tocolytics unless FFN and/or cervical length is assessed

SYMPTOMATIC WOMEN WEEKS GESTATION EFM PSYCHO-SOCIAL ASSESSMENT MEDICAL ASSESSMENT HISTORY SUPPORTIVE DATA PHYSICAL ASSESSMENT PRETERM LABOR ASSESSMENT PRETERM LABOR SUPPORTIVE CARE NOTIFY PHYSICIAN TESTS ORDERED UA RESULTS RISK ASSESSMENT  FLANK PAIN  SEXUAL INTERCOURSE  DEHYDRATION FETAL ASSESSMENT MEMBRANE STATUS POSITIONING HYDRATION PO OR IV LABS ULTRASOUND STERILE SPECULUM EXAM GROUP B STREP CULTURE FETAL FIBRONECTIN STERILE VAGINAL EXAM CERVICAL STATUS ASSESSMENT COMPONENTS OF PTL ASSESSMENT ALGORITHM

Preterm Labor Assessment Pre-Printed Physician Order Set Concise MD order set Rules out specific pathology Sterile speculum exam for fFN EFM monitoring for fetal wellbeing

Homecare Instructions Bedrest not effective Minimally restrictive Effective follow-up important Telephone calls Frequent office visits

Preterm Labor Patient Education “Street-smart” patients/clients Stay with the facts….decrease confusion Information is readily accessible Friendly, easy reading Warning signs to contact provider

Capping Off the Toolkit Sterile Speculum procedure GBS Procedure Nursing Competencies Sterile speculum exam Fern testing PTL Assessment Reference List

Preterm Labor Assessment Toolkit A great opportunity to : Standardize preterm labor assessment/disposition Maintain maternal/fetal safety Promote patient satisfaction ANY QUESTIONS??? Contact Mary Campbell Bliss at (916) or