Fibrinogen Levels in Acute Fatty Liver of Pregnancy and Postpartum Hemorrhage: A Report of Two Cases
Abstract Number: F2C-2
Abstract Type: Case Report/Case Series
Acute fatty liver of pregnancy (AFLP) occurs in 1/10,000-20,000 births. More than 90% of women present with nausea, vomiting, hypertension, or abdominal pain. Normally elevated in pregnancy, fibrinogen levels are commonly decreased in AFLP1. Thus, these women are frequently at risk for postpartum hemorrhage(PPH).
We present two cases of AFLP with low fibrinogen levels with vastly different presentations.
A healthy 32 year old G2P0010 presented at 37 weeks gestation with right upper quadrant pain, nausea, vomiting, polyuria and polydipsia. Vital signs were normal with the exception of tachycardia. Labs showed hematocrit 53.6%, platelets 205 k/uL, INR 1.82, fibrinogen 170 mg/dL, AST 259 U/L, ALT 536 U/L RC, total bilirubin 5.1 mg/dL, Na 141 mmol/L, and lactate 4.3. The fetal tracing showed decreased heart rate variability. The decision was made to proceed with emergency operative delivery under general anesthesia. The procedure was uncomplicated without excess blood loss. The fibrinogen nadir was 110 mg/dL. Two units of FFP and 10 units of cryoprecipitate were given in the recovery room for bleeding prophylaxis. The patient was discharged with a healthy baby on POD 12.
A healthy 36 year old G2P1001 twin gestation presented at 37 weeks with abdominal pain. Her vital signs were normal. Labs showed hematocrit 50.2%, platelets 156 k/uL, INR 1.4, fibrinogen 150 mg/dL, AST 266 U/L, ALT 443 U/L RC, total bilirubin 5.6 mg/dL, and lactate 3.5. The decision was made to proceed with operative delivery under general anesthesia. After twin delivery, bleeding was noted, and additional pitocin and carboprost were administered to treat uterine atony. Severe bleeding ensued requiring hysterectomy with transfusion of 2 units pRBCs, 1 unit FFP, and 5 units of cryoprecipitate. EBL was estimated to be 5 L. The patient was discharged with healthy twins on POD 5.
The hypercoagulable state of normal pregnancy is a protective mechanism to decrease the risk of hemorrhage. Low fibrinogen levels are associated with increased risk of PPH2. Fibrinogen levels < 100 mg/dL were thought to be the threshold for fibrinogen replacement, however, a recent study has shown that levels < 200 mg/dL have a positive predictive value of 100% for PPH3. In our cases fibrinogen levels were low, yet no excess bleeding occurred in the first patient. The second patient had hemorrhagic complications exacerbated by the coagulopathy of AFLP. Future studies should further investigate the correlation between fibrinogen level and bleeding in pregnancy.
1. Knight M et al.A prospective national study of acute fatty liver of pregnancy in the UK.Gut 2008;57:951-956.
2. Butwick,A.Postpartum hemorrhage and low fibrinogen levels:the past,present and future.In J Ob Anesth 2013;22;87-91.
3. Charbit B et al. The decrease of fibrinogen is an early predictor of the severity of postpartum hemorrhage. Journal of Thrombosis and Haemostasis 2007;5: 266–273.