Relation between maternal thrombophilia and stillbirth according to causes/associated conditions of death

ObjectiveTo investigate maternal thrombophilia in cases of Stillbirth (SB), also an uncertain topic because most case series were not characterised for cause/associated conditions of death.Study designIn a consecutive, prospective, multicentre design, maternal DNA was obtained in 171 cases of antenatal SB and 326 controls (uneventful pregnancy at term, 1:2 ratio). Diagnostic work-up of SB included obstetric history, neonatologist inspection, placenta histology, autopsy, microbiology/chromosome evaluations. Results audited in each centre were classified by two of us by using CoDAC. Cases were subdivided into explained SB where a cause of death was identified and although no defined cause was detected in the remnants, 64 cases found conditions associated with placenta-vascular disorders (including preeclampsia, growth restriction and placenta abruption — PVD). In the remnant 79 cases, no cause of death or associated condition was found.Antithrombin activity, Factor V Leiden, G20210A Prothrombin mutation (FII mutation) and acquired thrombophilia were analysed.ResultsOverall, the presence of a thrombophilic defect was significantly more prevalent in mothers with SBs compared to controls. In particular, SB mothers showed an increased risk of carrying Factor II mutation (OR = 3.2, 95% CI: 1.3–8.3, p = 0.01), namely in unexplained cases. Such mutation was significantly associated also with previous SB (OR = 8.9, 95%CI 1.2–70.5). At multiple logistic regression, Factor II mutation was the only significantly associated variable with SB (adj OR = 3.8, 95% CI: 1.3–13.5).ConclusionThese data suggest that Factor II mutation is the only condition specifically associated with unexplained SB and could represents a risk of recurrence. PVD-associated condition is unrelated to thrombophilia.