Cervicovaginal Fluid B-hCG Versus Fetal Fibronectin Assay in Prediction of Preterm Labor in Asymptomatic High Risk Women

Two hundred and twenty women with singleton pregnancies and risk factors for spontaneous preterm birth were included in this study. Cervico vaginal fluid sampling was undertaken for qualitative assessment of β -human chorionic gonadotropin (β-hCG) and fetal fibronectin(fFN)at 24 weeks of gestation.

For qualitative assay of both b-hCG and fFN, first vaginal specimens were collected by the following method:

Specimen collection

A sterile Cusco speculum was introduced into the vagina; the anterior lip of the cervix was grasped with sponge forceps and a cotton-tipped swab was placed into the external part of the endocervical canal (not reaching the internal os) and then into the posterior fornix (each for at least 1 min) to obtain an adequate sample of cervico vaginal secretions. Sampling was performed before doing any cervical manipulation (digital or ultrasound examination) and before introducing any vaginal material (lubricants or medications). The Hologic Specimen Collection Kit is the only acceptable specimen collection system which can be used to collect specimens for this assay. The polyester tipped swab provided in the Specimen Collection Kit should be inserted into the vagina and lightly rotated across the posterior fornix for approximately 10 seconds to absorb the cervico vaginal secretions. Once the specimen is obtained, carefully remove the swab from the vagina and place it into the tube of buffer provided with the Specimen Collection Kit. Two Specimen Collection Device per patient were obtained; one for each assay. Label the Specimen Transport Tubes with the patient's name and any other identifying information required.

All women were then followed up till delivery. Women were categorized into two arms: women who delivered preterm (before 37 completed weeks of gestation) and women who delivered at term (after 37 completed weeks of gestation).