Accuracy of tests for predicting spontaneous preterm birth: Systematic reviews of diagnostic research

Spontaneous preterm birth complicates about 3% of pregnancies before 34 weeks’ gestation and 7 – 12% before 37 weeks’ gestation. It is an important issue to public health worldwide. The aim of this thesis was to identify test(s) which would predict spontaneous preterm birth in early pregnancy when women are asymptomatic and in later pregnancy when they present with symptoms of threatened preterm labour, using systematic reviews and meta-analysis. If women at risk can be identified whether early in pregnancy or when they present with threatened preterm labour, interventions can be deployed to prevent or delay birth and to improve subsequent neonatal mortality/morbidity. Initially 40,243 title and abstract citations were scrutinised, resulting in shortlist of 1,650 full articles in which 319 were included in the systematic reviews, encompassing 22 tests. The quality of studies and accuracy of tests measured with likelihood ratio (LR) was generally poor. There were only a handful of studies for most of the tests. Few tests reached LR+ point estimates >5. In asymptomatic antenatal women these were ultrasonographic cervical funnelling and length measurement, cervico-vaginal prolactin and cervico-vaginal fetal fibronectin screening for predicting spontaneous preterm birth before 34 weeks’ gestation. In this group, tests with LR- point estimates approaching <0.2 were detection of uterine contraction (by mammary stimulating test) and amniotic fluid CRP measurement. In symptomatic women with threatened preterm labour tests with LR+ point estimate >5 were absence of fetal breathing movements, cervical length measurement, amniotic fluid IL6 and IL8, serum CRP and cervico-vaginal hcg for predicting birth within 2-7 days of testing. In this group tests with LR- point estimate <0.2 were measurement of cervico-vaginal hcg, cervical length measurement, absence of fetal breathing movement, amniotic fluid IL6 and IL8, and serum CRP for predicting birth within 2 - 7 days of testing. In conclusion, no exceptional, but many promising tests for predicting spontaneous preterm birth was identified to aid the development of evidence based practice.

Name dc:type.qualificationname

h_md

Level dc:type.qualificationlevel

h_md

Grantor dc:publisher.institution

University of Birmingham

Year dc:date.issued

2010

Author dc:creator

• Honest, H

• RG Gynecology and obstetrics
• RA0421 Public health. Hygiene. Preventive Medicine