Vaginal alpha-lipoic acid shows an anti-inflammatory effect on the cervix, preventing its shortening after primary tocolysis. A pilot, randomized, placebo-controlled study

Introduction: Inflammation might be an important underlying cause of preterm birth. Our aim is to explore whether vaginal administration α-lipoic acid reduces cervical inflammation and shortening after primary tocolysis. Materials and methods: Singleton pregnancies between 24–30 weeks remaining undelivered after hospitalization for preterm labor were randomly allocated to placebo (20 women, 15 analyzed) or vaginal ALA 400 mg (active ingredient 10 mg) daily (20 women, 17 analyzed) for 30 days. A cervical swab to quantify pro-inflammatory (IL1, IL2, IL6, IL8, TNFα) and anti-inflammatory (IL4, IL10) cytokines as well as transvaginal ultrasound cervical length measurement (CL) were performed before and after treatment. Results: The % changes of pro-inflammatory cytokines do not differ between treatment groups, while IL4 significantly increases by vaginal ALA in comparison to placebo (118.0 ± 364.3% versus 29.9 ± 103.5%, p = 0.012). Combined anti-inflammatory cytokines show same trend (292.5 ± 208.5% versus 64.5 ± 107.4, p = 0.03). CL remains similar in vaginal ALA group (from 23.1 ± 6.6 to 20.80 ± 7.9 mm), while it significantly decreased in placebo group (from 20.4 ± 6.5 to 13.8 ± 7.5 mm, p < 0.001 versus Baseline; p = 0.003 versus vaginal ALA). Conclusion: Vaginal ALA significantly stimulates anti-inflammatory ILs in the cervix of undelivered women after a preterm labor episode. This effect is associated with a stabilization of the CL.