Risk factors for preterm delivery: do they add to fetal fibronectin testing and cervical length measurement in the prediction of preterm delivery in symptomatic women?

Abstract

OBJECTIVE:

To assess whether patient characteristics add to the fetal fibronectin test and cervical length measurement in the prediction of preterm delivery in symptomatic women.

STUDY DESIGN:

A nationwide prospective cohort study was conducted in all ten perinatal centres in the Netherlands. Women with symptoms of preterm labour between 24 and 34 weeks gestation with intact membranes were invited. In all women qualitative fibronectin testing (0.050 μg/mL cut-off) and cervical length measurement were performed. Only singleton pregnancies were included in this analysis. Logistic regression was used to construct two multivariable models to predict spontaneously delivery within 7 days: a model including cervical length and fetal fibronectin as predictors, and an extended model including all potential predictors. The models were internally validated using bootstrapping techniques. Predictive performances were assessed as the area under the receiver operator characteristic curve (AUC) and calibration plots. We compared the models' capability to identify women with a low risk to deliver within 7 days. A risk less than 5%, corresponding to the risk for women with a cervical length of at least 25 mm, was considered as low risk.

RESULTS:

Seventy-three of 600 included women (12%) had delivered spontaneously within 7 days. The extended model included maternal age, parity, previous preterm delivery, vaginal bleeding, C-reactive protein, cervical length, dilatation and fibronectin status. Both models had high discriminative performances (AUC of 0.92 (95% CI 0.88-0.95) and 0.95 (95% CI 0.92-0.97) respectively). Compared to the model with fibronectin and cervical length, our extended model reclassified 38 women (6%) from low risk to high risk and 21 women (4%) from high risk to low risk. Preterm delivery within 7 days occurred once in both the reclassification groups.

CONCLUSION:

In women with symptoms of preterm labour before 34 weeks gestation, a model that integrates maternal characteristics, clinical signs and laboratory tests, did not predict delivery within 7 days better than a model with only fibronectin and cervical length.

• Authors: Gert-Jan van Baaren, Merel M C Bruijn, Jolande Y Vis, Femke F Wilms, Martijn A Oudijk, Anneke Kwee, Martina M Porath, Guid Oei, Hubertina C J Scheepers, Marc E A Spaanderman, Kitty W M Bloemenkamp, Monique C Haak, Antoinette C Bolte, Caroline J Bax, Jérôme M J Cornette, Johannes J Duvekot, Bas W A Nij Bijvanck, Jim van Eijck, Maureen T M Franssen, Krystyna M Sollie, Frank P H A Vandenbussche, Mallory Woiski, Patrick M M Bossuyt, Brent C Opmeer, Ben W J Mol
• Journal: European journal of obstetrics, gynecology, and reproductive biology (Eur J Obstet Gynecol Reprod Biol) Vol. 192 Pg. 79-85 (Sep 2015) ISSN: 1872-7654 [Electronic] Ireland
• PMID: 26182836 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Chemical References

• Fibronectins
• C-Reactive Protein

Topics

• Adult
• Area Under Curve
• C-Reactive Protein (metabolism)
• Cervical Length Measurement
• Delivery, Obstetric
• Female
• Fibronectins (analysis)
• Gestational Age
• Humans
• Labor Stage, First (physiology)
• Logistic Models
• Maternal Age
• Multivariate Analysis
• Netherlands (epidemiology)
• Parity
• Predictive Value of Tests
• Pregnancy
• Premature Birth (epidemiology)
• Prospective Studies
• ROC Curve
• Recurrence
• Risk Assessment (methods, statistics & numerical data)
• Risk Factors
• Symptom Assessment
• Time Factors
• Uterine Hemorrhage (epidemiology)
• Young Adult