Association of antenatal antithrombin activity with perinatal liver dysfunction : A prospective multicenter study

Background and Aim: Liver dysfunction with decreased antithrombin activity (AT) and/or thrombocytopenia is life-threatening in pregnant women. Whether AT is clinically useful for prediction of liver dysfunction remains unclear. Methods: A total of 541 women were registered prospectively at gestational week 34.7 (20.0 - 41.4) with available data on antenatal AT and platelet count (PLC). Results: Liver dysfunction defined as serum AST > 45 IU/L concomitant with lactate dehydrogenase (LDH) > 400 IU/L occurred in five women antenatally (≤ 2 weeks before delivery) and in 17 women postpartum (within 1 week postpartum). Median (5th - 95th) antenatal value was 85 (62 - 110)% for AT and 202 (118 - 315)×10^9/L for PLC in the 541 women, and was significantly lower in women with than without perinatal liver dysfunction; 75 (51 - 108) vs. 86 (62 - 110)% and 179 (56 - 244) vs. 203 (121 - 316)×10^9/L, respectively. Nineteen (86%) women with liver dysfunction showed AT ≤ 62% or thrombocytopenia (PLC ≤ 118×10^9/L) perinatally, but five lacked thrombocytopenia throughout the perinatal period. The best cut-off (AT, 77%; PLC, 139×10^9/L) suggested by receiver operating characteristic curve gave antenatal AT and PLC sensitivity of 59% and 41% with positive predictive value (PPV) of 8.6% and 14%, respectively, and combined use of AT and PLC improved sensitivity to 73% (16/22) with PPV of 9.2% for prediction of perinatal liver dysfunction. Conclusions: Reduced AT not accompanied by thrombocytopenia can precede liver dysfunction. Clinical introduction of AT may enhance safety of pregnant women.