Lactoferrin, an iron-binding glycoprotein found in cervical mucus and amniotic fluid, plays a defensive role against mucosal infections. This study examined the effect of recombinant human lactoferrin on preterm delivery in a rabbit model.

Anesthetized rabbits were randomly assigned to receive either inoculation with Escherichia coli or saline solution and to receive treatment with or without recombinant human lactoferrin inserted into the cervix 2 hours before bacterial inoculation (condition A: saline+saline; condition B: E coli+saline; condition C: E coli+recombinant human lactoferrin). E coli, saline solution, and recombinant human lactoferrin were inserted into the cervix using a hysteroscope and a sterile polyethylene cannula. Fetus survival rate and days to delivery after inoculation were monitored and tumor necrosis factor-⍺ concentrations were measured in maternal serum and amniotic fluid.

Fetus survival for conditions A, B, and C were 95.7%, 0%, and 32.6%, respectively, whereas pregnancy continuation was 7.00 ± 0 days, 3.25 ± 0.43 days, and 4.85 ± 1.77 days, respectively.

Cervical recombinant human lactoferrin administration increased fetal survival and extended pregnancy. Lactoferrin has an anti-inflammatory action as well as an antibacterial action, suggesting that recombinant human lactoferrin has the potential to prevent preterm delivery originating from cervical infection in the clinical setting.