The Role of PTB Clinics: A Review of the Screening Methods, Interventions and Evidence for Preterm Birth Surveillance Clinics for High-Risk Asymptomatic Women

Abstract

Context: Preterm birth accounts for significant neonatal mortality and morbidity as well as substantial health costs. As our understanding of aetiology and risk factors for preterm birth increases, predictive tools and prophylactic interventions have been developed to improve maternal and fetal outcomes. These are effective, but require surveillance of asymptomatic high-risk women, as well as ultrasound and surgical expertise. This has led to the development of preterm birth surveillance clinics (PSCs), which pool these resources together and have changed the focus of care from reactive to predictive and preventative management. Methods: A literature review of the evidence surrounding the predictive tests (cervical length, fetal fibronectin, Actim Partus, Partosure) and prophylactic interventions (cerclage, progesterone, Arabin pessary, antibiotics, and steroids) for preterm birth to understand what preterm birth surveillance clinics do and how effective they are. Results: Measuring cervical length and fetal fibronectin levels are two of the most accurate predictive tests preterm birth, especially when used in combination. Other predictive tools like Actim Partus and Partosure are effective for symptomatic women, but their role in surveillance of asymptomatic women is unclear. Cervical cerclage is effective in reducing preterm birth in women with previous losses, but the role of progesterone and pessaries remains debated. Steroids remain one of the most effective antenatal intervention, but they need to be administered within a tight timeframe in order to confer maximal benefit. The role of PSCs in predicting the timing of birth and targeting women at highest risk to appropriate interventions is therefore crucial in optimizing care and improving outcomes. Conclusions: Nearly every step of management is still debated although many have a strong evidence-base and effective interventions do exist. The challenge is finding the optimal management pathway, and details of which populations benefit from which interventions need to be evaluated. While evidence continues to be collated, the poor outcomes of preterm birth and the multiple options available to reduce them justify preterm birth surveillance clinics being resourced.Keywords: Preterm Birth, Predictive, Fetal Fibronectin, Cervical Length, Cervical Cerclage ContextDefined as spontaneous or induced birth before 37+ 0 weeks' gestation, preterm birth (PTB) is responsible for significant perinatal morbidity and mortality. Preterm labour affects 11.1% of live births worldwide (1) and 7.6% of live births in England and Wales (2), but incidence is rising globally (3). PTB causes more than 3 million perinatal deaths a year (1) and causes increased risks of neurodevelopmental impairment, behavioural problems and respiratory diseases, which constitute significant health costs and decreased quality of life (4-6). MethodsThe primary research question our review is addressing is "what predictive tests and prophylactic interventions to preterm birth surveillance clini...

Obstetric strategies to reduce blindness from retinopathy of prematurity in infants born preterm

“…Smoking cessation programs and treatment of sexually transmitted infections in pregnancy have shown a modest reduction in PTB rates . Vaginal progesterone and cervical cerclage have a role, but evidence supports use only in women with multiple previous PTBs or those who develop a short cervix in the mid‐trimester …”

“…Few women who present with symptoms of threatened preterm labor deliver preterm; 3.9% within 14 days of presentation and 21% before 37 weeks’ gestation . Transvaginal ultrasound cervical length and vaginal biomarkers are more accurate predictors of who will deliver within the next 14 days than are symptoms alone, and should be used when available …”

“…5,8 Vaginal progesterone and cervical cerclage have a role, but evidence supports use only in women with multiple previous PTBs or those who develop a short cervix in the mid-trimester. 9 Reducing rates of medically indicated PTB is likely to reduce neonatal morbidity including ROP, although direct evidence is not available. For women at risk of preeclampsia or fetal growth restriction, early use of low-dose aspirin provides an 8% risk reduction in PTB and a 10% lower risk of small-for-gestational-age (SGA) babies.…”

“…10 Transvaginal ultrasound cervical length and vaginal biomarkers are more accurate predictors of who will deliver within the next 14 days than are symptoms alone, and should be used when available. 9 Tocolysis can provide a short-term delay for women with threatened or established preterm labor to allow for interventions that improve perinatal outcomes, 8 such as (1) antenatal corticosteroids, (2) magnesium sulfate to reduce cerebral palsy and (3) in utero transfer to ensure birth occurs in a hospital with appropriate level neonatal services. 5 The World Health Organization strongly recommends a course of antenatal corticosteroids for women at risk of preterm birth at 24 +0 to 34 +6 weeks when gestational age is known, preterm birth is imminent, there is no clinical evidence of maternal infection, and obstetric and newborn care are available.…”

The use of specialised preterm birth clinics for women at high risk of spontaneous preterm birth: a systematic review

“…Despite considerable research efforts there is no effective treatment to stop preterm labour once it has established and current management focuses on prevention [3,4]. In recent years, specialised preterm birth clinics have developed due to a growing understanding of risk factors for preterm birth and the importance of risk stratification to guide the use of interventions to prevent preterm labour [5]. To the best of our knowledge, the first modern-day preterm birth clinic was established in the United Kingdom (UK) in 1998.…”