We aimed to investigate the effects of colchicine use on first and second trimester screening markers in pregnancies complicated with familial Mediterranean fever (FMF) and to evaluate the overall impact of these effects on perinatal outcomes.

A retrospective case-control study was conducted in pregnancies complicated with FMF using colchicine and healthy pregnancies as controls without any defined risk factors and medication use. Biochemical markers for the aneuploidy screening, including free ß-hCG and PAPP-A in the first trimester, and AFP, HCG, and unconjugated estriol (uE3) in the second trimester, were recorded, and MoM levels of these markers were compared between the FMF and control groups. Obstetric history and outcomes were also compared between groups. We used propensity score matching to form a cohort in which patients had similar baseline characteristics.

Among 93 eligible pregnant women, 31 women in FMF group and 31 in control group had similar propensity scores and were included in the analyses. Levels of serum-free ß-hCG, PAPP-A and AFP were similar between FMF and control groups (p = 0.671, p = 0.387 and p = 0.963, respectively). For the second-trimester markers, maternal serum uE3 MoM level were significantly lower in the FMF group using colchicine than in the controls (p = 0.045). We also compared these markers according to the daily colchicine dose between FMF subgroups. We did not detect significant difference between the different colchicine treatment modalities (0.5–1 mg/day vs. 1.5–2 mg/day, p > 0.05).

Maternal biochemical serum markers of an aneuploidy screening test in the second trimester may be affected by FMF with colchicine use, leading to misinterpretation of the risk level of tests. For these tests with decreased uE3 levels, FMF and colchicine use should be considered as a causative etiology after ruling out common etiologies and confounding factors before recommending invasive diagnostic testing.