Table 1.

Summary of commonly used tests to predict preterm labor.

Method	Approach	Advantages	Disadvantages
Risk scoring	Computer-based algorithm to determine risk	Essentially “no cost” Fairly rapid and easy to perform	Requires extensive demographic and medical history information Poor predictive utility
Cevical length	Transvaginal ultrasonography	Can be incorporated during routine antenatal examination Essentially “no additional cost” Provides useful information on the state of the cervix Fairly rapid to perform	Expensive ultrasound equipment required Requires skilled ultrasonographer Limited predictive utility but may be a useful adjunct to biochemical tests
Biochemical tests	“Dip-stick” tests Quikcheck (fFN) Actim partus (phIGFBP1)	Rapid and easy to perform Good negative predictive value	Moderately expensive analyzer Expensive single test May be influenced by contaminants (blood, amniotic fluid, semen) Semi-quantitative Predetermined threshold cut-off Poor positive predictive value
	Immunoassay Rapid TLiIQ (fFN)	Rapid and easy to perform Good negative predictive value	Moderately expensive analyzer Expensive single test May be influenced by contaminants (blood, amniotic fluid, semen) Semi-quantitative Predetermined threshold cut-off Poor positive predictive value
	Immunoassay Rapid 10Q (fFN)	Rapid and easy to perform Accurate quantification Ability to choose the desired threshold cut-off Good negative predictive value	Moderately expensive analyzer Expensive single test May be influenced by contaminants (blood, amniotic fluid, semen) Poor positive predictive value