Perinatal Quality Foundation (www.perinatalquality.org) Why Measure Cervical Length Lecture 1 Perinatal Quality Foundation (www.perinatalquality.org)

Lecture 1 Spontaneous Pre-term Birth (sPTB) Preventing sPTBS Screening test requirements Cervical Length Screening for sPTB Interventions for Short Cervix Society Statements

Little Babies Create Big Problems Preterm birth 1400 premature babies born daily in US 1 of 8 births Costs exceed $26 billion annually in US Even higher rates worldwide Complications Neonatal: respiratory morbidity, necrotizing entercolitis, intraventricular hemorrhage Childhood: 20% of mental retardation, 30% of vision impairment, and 50% of cerebral palsy is due to PTB Lifelong: risks increased for heart disease, diabetes, cancer, etc.

How do we Prevent Disease? Primary Protect healthy people from developing the disease Education, lifestyle changes, nutrition, etc Secondary Early detection to slow or halt disease Screening useful only if specific requirements met Tertiary Manage when disease occurs Typical allopathic medicine approach, but often too late

Preventing spontaneous PTB Primary Nutritional supplements Dental care Secondary Selection of high risk patients for treatment Cervical length screening Tertiary Tocolytics (drugs to suppress contractions) Antibiotics Anti-inflammatory agents

No Primary or Tertiary approaches have been proven effective Preventing sPTB No Primary or Tertiary approaches have been proven effective

Preventing sPTB Some secondary strategies are effective Selection of high-risk patients (intramuscular progesterone for patients with a history of sPTB) Cervical length screening

What Defines a Good Screening Test? Disease Clinically important, clearly defined, with a well known prevalence and recognizable early asymptomatic phase Technique Well described, safe and acceptable, has a reasonable cutoff identified, reproducible results (reliable), and accurate results (valid) Intervention, cost-effectiveness and feasibility Early intervention is effective, screening and treating abnormals is cost-effective, facilities for screening and treatment are readily available

Cervical Length is a Good Screening Test Criterion: Disease Comments Disease is clinically important PTB is leading cause of perinatal morbidity/mortality, with more than 1 million deaths annually worldwide Disease is clearly defined Birth <37weeks Disease prevalence is well known 12% in US, about 10% worldwide Disease natural history is known / Recognizable early asymptomatic phase Cervical length inversely related to sPTB risk, and early cervical changes occur at the internal os TVU of the cervix is a screening test, NOT a DIAGNOSTIC test (I totally disagree with TVU being a diagnostic test: just because a cervix is short, it’s not insufficient/incompetent – many other reasons, as will see later). CI cannot be diagnosed with this test alone.

Cervical Length is a Good Screening Test Criterion: Technique Comments Screening technique well described Several articles document technique Screening is safe and acceptable RCT on PPROM showing safety* 99% would have it again; <2% have severe pain Screening has a reasonable cutoff identified 20mm is the 5th percentile, 25mm is the 10% percentile in the general US population** Results are reliable (reproducible) <10% intra- and inter-observer variability Results are accurate (valid) Better than manual exam; predictive in all populations studied (hundreds of studies) *Carlan, Obstet Gynecol 1993; 81:61 **Iams, N Engl J Med 1996; 334:567

Cervical Length is a Good Screening Test Criteria: Intervention, cost-effectiveness, feasibility Comments ‘Early’ intervention is effective 2 RCTs showed benefit of vaginal progesterone Screening and treating abnormals is cost-effective 2 manuscripts support cost-effectiveness Facilities for screening are readily available All pregnancies offered USN for fetal anatomy screening at 18-24 weeks Facilities for treatment are readily available Vaginal progesterone is easy to obtain and administer as outpatient

Intervention for Short Cervix is Effective Vaginal progesterone (90mg gel) reduces risk by 45% in high and low risk women with CL 10- 20 mm RCT, n=32,091 screened and n=458 randomized Hassan, Ultrasound Obstet Gynecol 2011;38:18

Intervention for Short Cervix is Effective Vaginal progesterone (200mg suppository) reduces risk by 44% in high and low risk women with CL <15mm RCT (n=24,620 screened, n=250 randomized) Fonseca, N Engl J Med 2007;357:462

Intervention for Short Cervix is Effective Cerclage reduces sPTB by 30% in women with a history of sPTB and a cervix <25mm before 24 weeks gestation Berghella, Obstet Gynecol 2011;117:663 Owen, Am J Obstet Gynecol 2009; 201:375

Intervention for Short Cervix is Effective Cerclage in women using 17OHPC who develop a short cervix <25mm shows a trend toward benefit (study not powered for this result) PTB <28w (%) Similarly, women with a prior PTB and a short CL<25mm had a 34% risk of PTB<32w if they received neither 17P or cerclage, 25% if they received cerclage, 21% if they received 17P, and 17% if they received both. Berghella, Am J Obstet Gynecol 2010;202:351

ACOG on CL screening Cervical length measured by transvaginal ultrasound examination is a useful screening test for predicting spontaneous preterm birth. Cervical length screening by transvaginal ultrasound examination is safe, highly reproducible, and more useful in predicting preterm birth than transabdominal ultrasound examination. Cervical length screening is most useful for predicting preterm birth in women who have had a prior preterm birth and have a singleton gestation. ACOG Committee Opinion 522, Obstet Gynecol 2012:119:879

SMFM on CL screening There is level I evidence of prevention of PTB and neonatal benefits based on treating with vaginal progesterone low-risk singleton gestations identified with TVU screening to have a short CL. This strategy is not only beneficial in terms of improvement in health in a condition (PTB) of utmost importance to society, but also cost-effective, and in fact cost-saving. TVU CL is a safe, acceptable, reproducible and accurate screening test, with potentially widespread availability. Berghella, SMFM Publication Committee, Am J Obstet Gynecol 2012:10:1016

Summary ACOG: The utility of universal cervical length screening for the prevention of preterm birth is controversial and being debated. SMFM: Cervical length screening in singleton gestations without prior preterm birth cannot yet be mandated universally. Nonetheless, implementation of such a screening strategy should be viewed as reasonable, and can be considered by individual practitioners ACOG Committee Opinion 522, Obstet Gynecol 2012:119:879 Berghella, SMFM Publication Committee, Am J Obstet Gynecol 2012:10:1016

Summary: Twins ACOG: There are insufficient data on the efficacy of interventions for the prevention of preterm birth in women with multiple gestations with both a prior preterm birth and a short cervical length. Cerclage may increase preterm birth in women with a twin pregnancy and a cervical length of less than 25mm is not recommended at this time. SMFM: The evidence does not support the use of any type of progestogen for prevention of PTB in multiple gestations with unknown CL. There is insufficient evidence to assess the effect of progestogens in women with both multiple gestation and short CL. ACOG Committee Opinion 522, Obstet Gynecol 2012:119:879 Berghella, SMFM Publication Committee, Am J Obstet Gynecol 2012:10:1016

Training/Quality Control Regardless of whether practitioners choose to screen universally or selectively, correct technique is critical to avoiding incorrect diagnosis and treatment. SMFM: TVU CL needs to be performed with proper technique in order to yield accurate results, with quality control and monitoring Berghella, SMFM Publication Committee, Am J Obstet Gynecol 2012:10:1016

Training/Quality Control Elements of effective training: Didactic education Image review with standardized criteria