Fetal fibronectin (Quick Check fFN test(®)) for detection of premature rupture of fetal membranes.

OBJECTIVES

This study was designed to detect the accuracy of the fetal fibronectin (Quick Check fFN test(®)) in diagnosing premature rupture of fetal membranes.

STUDY DESIGN

This comparative prospective study was carried out over 1 year in Ahmadi Kuwait Oil Company (KOC) Hospital, Kuwait from March 2011 till March 2012.

PATIENTS AND METHODS

Two hundred and twenty (220) pregnant women >34 and <37 weeks gestation were included in this study and divided into two groups according to presence or absence of PROM; 110 patients with PROM were included in group I, and 110 patients without PROM were included in group II as controls. Patients with multiple pregnancies or >37 weeks gestation or not sure of dates or fetal distress or vaginal bleeding or preterm labor or chorioamnionitis were excluded from this study. The diagnosis of PROM was based on patient's history of sudden gush of water, pooling of amniotic fluid, positive ferning pattern, positive nitrazine test, confirmed by visualization of fluid passing from the cervical canal during sterile speculum examination and Trans-abdominal ultrasound to measure the amniotic fluid index (AFI ≤ 5 cm in PROM). The gestational age was calculate from the first day of LMP and confirmed by early ultrasound scan (done before 20 weeks gestation). Patients included in this study were subjected to standard examination, trans-abdominal ultrasound and sterile speculum examination to detect amniotic fluid pooling through the cervical canal and for collection of samples on admission. Some laboratory investigations were done to exclude chorioamnionitis (maternal fever, maternal tachycardia, fetal tachycardia, maternal leucocytosis, CRP).

RESULTS

In this study, the sensitivity and the specificity of fetal fibronectin in diagnosing PROM were 94.5 and 89.1 %, respectively, as compared with 84.5 % sensitivity and 78.2 % specificity for Ferning test, respectively, and 87.3 % sensitivity and 80.9 % specificity for Nitrazine test, respectively. The PPV and NPV of fetal fibronectin were 89.7 and 94.2 %, respectively, as compared with 79.5 % PPV and 83.5 % NPV for Ferning test, respectively, and 82.1 % PPV and 86.4 % NPV for Nitrazine test, respectively. Fetal fibronectin was more accurate (91.8 %) for detection of PROM than Ferning (81.4 %) or Nitrazine (84.1 %) tests.

CONCLUSION

The Quick Check fFN test(®) for detection of the fetal fibronectin in the vaginal fluid is a simple bedside test, more sensitive, and specific than Ferning and Nitrazine tests, it can be used as complimentary test to confirm the clinical diagnosis of premature rupture of fetal membranes.