Viscoelastic Hemostatic Assays for Postpartum Hemorrhage.

This article discusses the importance and effectiveness of viscoelastic hemostatic assays (VHAs) in assessing hemostatic competence and guiding blood component therapy (BCT) in patients with postpartum hemorrhage (PPH). In recent years, VHAs such as thromboelastography and rotational thromboelastometry have increasingly been used to guide BCT, hemostatic adjunctive therapy and prohemostatic agents in PPH. The three pillars of identifying hemostatic competence include clinical observation, common coagulation tests, and VHAs. VHAs are advantageous because they assess the cumulative contribution of all components of the blood throughout the entire formation of a clot, have fast turnaround times, and are point-of-care tests that can be followed serially. Despite these advantages, VHAs are underused due to poor understanding of correct technique and result interpretation, a paucity of widespread standardization, and a lack of large clinical trials. These VHAs can also be used in cases of uterine atony, preeclampsia, acute fatty liver of pregnancy, amniotic fluid embolism, placental abruption, genital tract trauma, surgical trauma, and inherited and prepartum acquired coagulopathies. There exists an immediate need for a point-of-care test that can equip obstetricians with rapid results on developing coagulopathic states. The use of VHAs in predicting and treating PPH, although in an incipient state, can fulfill this need.

The Impact of Hepatitis C Virus Infection on Buprenorphine Dose in Pregnancy.

OBJECTIVE: Buprenorphine (BUP) is commonly used for opioid maintenance therapy in pregnancy. Our goal was to determine whether liver dysfunction related to hepatitis C virus (HCV) infection impacts BUP dosing requirements in pregnancy. STUDY DESIGN: This was a retrospective cohort study of pregnant women with antenatal exposure to BUP to compare dosing between individuals positive versus negative for HCV infection. Spearman correlation tests were used to assess the relationship between BUP dose and HCV status. RESULTS: HCV infection was present in 103 (39%) of the patients. Patients with HCV infection required lower dose increases of BUP throughout pregnancy (p = 0.02). HCV viral load was positively correlated with the liver enzymes aspartate transaminase (r = 0.30, p = 0.003) and alanine transaminase (r = 0.25, p = 0.01). There was a negative correlation between HCV viral load and BUP dose during the second trimester (r = -0.27, p = 0.01) and third trimester (r = -0.20, p = 0.04). CONCLUSION: Women with HCV infection required less of an increase in BUP dose throughout pregnancy compared with women without HCV infection. Severity of HCV infection, as measured by viral load and liver enzymes, was also associated with BUP dosing.

Positive cell-free fetal DNA testing for trisomy 13 reveals confined placental mosaicism.

PURPOSE: We report on a case in which cell-free fetal DNA was positive for trisomy 13 most likely due to confined placental mosaicism. Cell-free fetal DNA testing analyzes DNA derived from placental trophoblast cells and can lead to incorrect results that are not representative of the fetus. METHODS: We sought to confirm commercial cell-free fetal DNA testing results by chorionic villus sampling and amniocentesis. These results were followed up by postnatal chromosome analysis of cord blood and placental tissue. RESULTS: First-trimester cell-free fetal DNA test results were positive for trisomy 13. Cytogenetic analysis of chorionic villus sampling yielded a mosaic karyotype of 47,XY,+13[10]/46,XY[12]. G-banded analysis of amniotic fluid was normal, 46,XY. Postnatal cytogenetic analysis of cord blood was normal. Karyotyping of tissues from four quadrants of the placenta demonstrated mosaicism for trisomy 13 in two of the quadrants and a normal karyotype in the other two. CONCLUSION: Our case illustrates several important aspects of this new testing methodology: that cell-free fetal DNA may not be representative of the fetal karyotype; that follow-up with diagnostic testing of chorionic villus sampling and/or amniotic fluid for abnormal test results should be performed; and that pretest counseling regarding the full benefits, limitations, and possible testing outcomes of cell-free fetal DNA screening is important.

Alternate evaluations of proteinuria in the gravid hypertensive patient.

OBJECTIVE: To determine if the 12-hour urine total protein value correlates with the 24-hour value and to evaluate the random protein:creatinine ratio as a predictor of significant proteinuria (> or = 300 mg/24 h) for use in diagnosing preeclampsia. STUDY DESIGN: The study population included 15 patients with hypertensive disorders of pregnancy. The patients' urine was collected over 24 hours in 2 12-hour aliquots. The urine volume, total protein and creatinine were measured. The patients' initial voids were collected and evaluated for random urine protein and creatinine and calculation of the protein:creatinine ratio. The protein:creatinine ratio and 12-hour results were compared to the 24-hour results using simple regression analysis. RESULTS: Of the 15 patients, 6 had no proteinuria, 5 had mild proteinuria, and 4 had severe proteinuria (60% with significant proteinuria). The 12-hour protein results correlated with the 24-hour results for patients with mild disease (p = 0.00007, first 12 hours, and p = 0.012, second 12 hours) and severe disease (p = 0.014 and p = 0.007). The results for no disease were mixed: for the first 12 hours there was a poor correlation, but the results for the second 12 hours correlated well. The protein:creatinine ratio had a significant correlation (p = 0.02), using a cutoff of 0.15, returned specificity of 50%, sensitivity of 100%, positive predictive value of 75% and negative predictive value of 100%. CONCLUSION: Total protein values for 12- and 24-hour urine samples correlate well for the diagnosis of preeclampsia. A protein:creatinine ratio of < or = 0.15 rules out significant proteinuria. In combination, these 2 tests may allow more rapid diagnosis of preeclampsia.