The Obstetrical Society of Philadelphia Shared Quality Initiatives in Obstetrical Care Cervical Length Screening in Obstetrics Jason K. Baxter, MD, MSCP Director of Inpatient Obstetrics Division of Maternal-Fetal Medicine Department of Obstetrics and Gynecology Thomas Jefferson University November 17th, 2012
Preterm birth (PTB) is our greatest problem • A new prediction and prevention paradigm is needed: • Transvaginal ultrasound cervical length (TVCL) • Vaginal progesterone for short cervix • National guidelines • Proposed Philadelphia guideline for universal TVCL screening
12.8% 12.0% % CDC 2012
Cervical Length Bladder Ext Os Int Os Fetal Head Posterior Cervical Lip
800 14 700 Relative Risk 12 No. of women 600 10 500 8 400 No. of Women Relative Risk of Premature Delivery 6 300 4 200 2 100 0 0 2 4 8 12 16 20 24 28 32 36 40 44 48 52 56 60 64 68 Length of Cervix (mm) 1 5 10 25 50 75 Percentile Iams JD et al. N Engl J Med. 1996;334:567-572.
Is TransvaginalUltrasound (TVU) aGood Screening Test for PTB? • Important condition (PTB) • Technique well-described • Safe and acceptable • Reliable (reproducible) • Recognizable early asymptomatic phase • Valid (accuracy of prediction) • ‘Early’ treatment is effective (Prevention)
Vaginal Progesterone for Short Cervix andGestational Age at Delivery Hassan SS et al. Ultrasound Obstet Gynecol. 2011;38:18-31.
Vaginal Progesterone for Short Cervix andNeonatal Outcomes Hassan SS et al. Ultrasound Obstet Gynecol. 2011;38:18-31.
All Viable, Singleton Pregnancies at Anatomy Scan (18 0/7 -23 6/7 Weeks) Excludes: Multiples Cerclage Present Transvaginal Ultrasound for Cervical Length ≤20 mm Clinically significant cervical shortening 21 – 24.9 mm Borderline cervical shortening ≥25 mm Normal cervical length GA < 23 0/7 wks MFM Consult for Counseling and Intervention Recommendations Yes No No further screening or intervention Repeat Scan by 23rd Wk CL ≤20mm Yes No
Singleton gestations, no prior PTB, and short CL ≤ 20 mm at ≤ 24 weeks, vaginal progesterone, either 90-mg gel or 200-mg suppository, is associated with reduction in PTB and perinatal morbidity and mortality SMFM, AJOG May 2012
Recommendations: Cervical Length Screening • The issue of universal CL screening of singleton gestations without prior PTB for the prevention of PTB remains an object of debate • CL screening in singleton gestations without prior PTB cannot yet be universally mandated • Nonetheless, implementation of such a screening strategy can be viewed as reasonable, and can be considered by individual practitioners, following strict guidelines SMFM, AJOG May 2012
While there are barriers to implementing a universal cervical length screening policy, the document offers detailed guidelines to help individual clinicians start using this risk assessment strategy immediately. • Cost-effectiveness studies have shown that cervical length screening is associated with lower overall costs and improved neonatal health. The SMFM Guidelines therefore recommend that third-party payers cover the cost of cervical length measurement to evaluate risk for preterm birth. SMFM, AJOG May 2012
Concerns with Universal Cervical Length Screening • Implementation logistics • Lack of availability of TVU • Potential for unnecessary/unproven interventions • Quality assurance
TVU Training Program • CLEAR: Cervical Length Education and Review • www.PerinatalQuality.org • Free course • Web-based exam & CME • Cervical length image review • Documentation of completion
Cervix Measurement Image Criteria • Transvaginal Image • Cervix Occupies 75% of the Image • Anterior Width = Posterior Width • Maternal Bladder Empty • Internal Os Seen • External Os Seen • Cervix Canal Visible Throughout • Caliper Placement Correct • Cervix Mobility Considered
Data are currently insufficient to suggest benefit, or harm, of transabdominal screening of CL for prevention of PTB using progesterone or any other intervention as therapy if a short CL is identified. • The randomized data on benefit from vaginal progesterone for women with short CL screened women utilizing TVU SMFM, AJOG May 2012
American College of Nurse-Midwives. Prevention of Preterm Labor and Preterm Birth. Position statement. http://www.midwife.org/documents/Prevention of Preterm Labor and Preterm Birth.pdf. Published June 2012.
ACOG PTB Prevention Practice Bulletin Cervical Screening Recommendations: • Cervical length measurement should be taken at 18 to 22 gestational weeks, at the same time as the ultrasound for fetal anatomic survey • Women with cervical length less than 25 mm at 14 to 28 weeks should undergo a subsequent TVU to confirm this finding. • Women in whom short cervical length is confirmed should have a review of risk factors for preterm birth, as well as of management options. • TVU measurement of cervical length should be performed only when interventions to reduce risk for preterm birth are available. • The utility of universal cervical length screening to prevent preterm birth is still controversial and under debate.
Proposed Philadelphia Guideline for Cervical Length Screening in Obstetrics
Cervical Length Screening for Prevention of Preterm Birth Patient Eligibility for Screening • Singleton, viable pregnancy • Gestational age 18 0/7 – 23 6/7 weeks • Non-Eligible: multiple gestation, presence of cerclage in current pregnancy
Cervical Length Screening for Prevention of Preterm Birth Technical Aspects of Screening • Post-void transvaginal ultrasound to anterior fornix • Sagittal view of cervix with echogenic endocervix along length of canal • Withdraw probe until blurred, then reinsert making sure to avoid excessive pressure • Enlarge image to occupy 2/3 of screen • Obtain three measurements to use the best, shortest image • Measure from internal to external os along entire endocervical canal • Transfundal pressure for 15 seconds, then 3 more measurements • Report only shortest best CL
Cervical Length Screening for Prevention of Preterm Birth Definition of Short Cervix • Patients with CL ≤ 20mm are identified to have clinically significant cervical length shortening warranting consideration for available therapy
Conclusions • Preterm Birth is our greatest obstetrical problem • Universal TVU screening with vaginal progesterone treatment of a short cervix • reduces the risk of PTB • improves neonatal outcomes • is cost saving