Fetal fibronectin testing and pregnancy outcomes among Texas Medicaid patients at risk for preterm birth

Fetal fibronectin (fFN) testing between the 24th and 34th weeks of pregnancy in patients with symptomatic preterm labor (PTL) helps assess the risk of spontaneous preterm birth (sPTB), yet the extent of its use is unknown. We assessed use of fFN testing among Texas Medicaid enrollees with symptomatic PTL and evaluated time to infant delivery and healthcare utilization/costs.

Retrospective cohort study using medical and pharmacy claims for Texas Medicaid enrollees.

We identified pregnant women triaged through the emergency department (ED) and hospital labor-and-delivery units with symptomatic PTL between January 1, 2012, and May 31, 2015. Patients with fFN testing prior to delivery were propensity score matched 1:1 to patients without fFN testing. Primary outcomes included time to delivery from initial PTL encounter and all-cause maternal healthcare utilization and costs.

A total of 29,553 women met the criteria for analysis, of whom 14% had a record of receiving fFN testing. Each matched cohort included 4098 patients. Compared with those who did not, patients who underwent fFN testing had significantly more clinical risk factors (mean [SD]: 1.7 [1.1] vs 1.1 [1.0]; P <.0001) and were less likely to deliver during the initial hospital stay (odds ratio [OR], 0.539; 95% CI, 0.489-0.594), deliver ≤3 days following the hospital/ED encounter (OR, 0.499; 95% CI, 0.452-0.551); and receive their first PTL diagnosis during the initial hospital/ED encounter (OR, 0.598; 95% CI, 0.539-0.665). Patients who had an fFN test, compared with those who did not, had 17.5% higher total costs (P <.0001) during the 5 months prior to delivery, but had gestation lengths 9.4 days longer (24.6 vs 15.2 days) than those without testing.

Frequency of fFN testing was low in Texas Medicaid enrollees with symptomatic PTL. Patients with fFN testing had longer gestation periods and were less likely to deliver within ≤3 days of a hospital/ED encounter for PTL. These results support the role of fFN in screening for risk for sPTB among women with symptomatic PTL.