Abstract
Objective. To assess the efficacy of the cervical phosphorylated insulin-like growth factor binding protein-1 (pIGFBP-1) in combination with cervical length measurement for the prediction of preterm delivery. Design. Observational prospective study. Setting. University Hospital, Spain. Sample. A total of 276 women between 24 and 34 weeks gestational age complaining of uterine contractions and intact membranes. Methods. Transvaginal scan to assess cervical length and cervical swabs for pIGFBP-1 detection. Main outcome measures. Prevalence of preterm delivery within 48 hours and 7 days, delivery at < 32, < 34 weeks, admission-to-delivery interval by cervical length and the presence of pIGFBP-1. Results. The prevalence of preterm delivery at < 34 weeks was 14.1% (39/276) and 7.6% (21/276) at < 32 weeks. Cervical pIGFBP-1 was positive in 38.7% (107/276), whereas cervical length < 15 mm was present in 7.2% (20/276) and was > 30 mm for 64.8% (179/276) of the women. The presence of a positive pIGFBP-1 appeared useful for prediction of delivery before 32 (likelihood ratio (LR) = 2.21, confidence interval (CI): 1.63–3.00) and 34 weeks (LR = 1.76, CI: 1.25–2.41), respectively. Receiver operating characteristic curves were significant for cervical length and pIGFBP-1 for prediction of delivery at < 34 weeks, < 32 weeks, < 48 hours and < 7 days. Combining pIGFBP-1 and cervical length had a median interval that was shorter when both were positive as compared to only one positive or both negative, but the CIs overlapped. Conclusions. Both cervical length measurement and pIGFBP-1 are useful for prediction of spontaneous preterm delivery. A pIGFBP-1 positive result associated with cervical length does not improve preterm delivery prediction rates.
Acknowledgements
This paper was prepared in collaboration with Mr. Sailesh Kumar, DPhil, FRCOG, FRCS, Consultant Obstetrician and Gynecologist, Queen Charlotte and Chelsea Hospital, Imperial College NHS Trust, London. The study was supported by a grant from the Agencia Valenciana de Salud exp 043/07.
Disclosure of interest: The authors declare no conflicts of interest.