The influence of obesity on coagulation in healthy term pregnancy as assessed by rotational thromboelastometry.

Background: Rotational thromboelastometry (ROTEM®) is a point‐of‐care coagulation test which has been used to demonstrate hypercoagulability in pregnant populations and obese populations. Aim: The aim of this study was to assess the combined effect of pregnancy and obesity on coagulation using ROTEM® in healthy pregnant women of varying body mass indices (BMIs) presenting for elective caesarean delivery. Materials and Methods: Ethics approval was granted for recruitment of women presenting for elective caesarean delivery. Women with any condition affecting coagulation were excluded. The ROTEM® parameters of extrinsically activated thromboelastometric test / fibrin polymerisation test (EXTEM/FIBTEM) amplitude at five minutes (A5), coagulation time (CT), maximum clot firmness (MCF) and clot formation time (CFT) were compared between three different groups: normal weight, overweight and obese women. Results: One hundred and eighty‐five women presenting for elective caesarean delivery met inclusion criteria and were divided into three groups; normal weight (BMI < 25 kg/m2, n = 86), overweight (BMI 25–29.9 kg/m2, n = 54) and obese (BMI ≥ 30 kg/m2, n = 45). They had a mean (SD) age of 32.7 ± 5.0 years and the median (interquartile range) BMI of 21.9 kg/m2 (20.5–23.0), 27.0 kg/m2 (26.0–28.5), 36.0 kg/m2 (32.2–41.8) for the normal weight, overweight and obese groups respectively. Forty‐one (22.2%) women were nulliparous. Across the three groups for FIBTEM A5 (P = 0.018), FIBTEM MCF (P = 0.032), FIBTEM CFT (P = 0.047) and EXTEM MCF (P = 0.015) there was evidence of increasing coagulability with increasing BMI. However, following Bonferroni correction, this was no longer significant. Conclusions: There is no association between BMI and ROTEM® parameters in pregnant women presenting for elective caesarean delivery at term. [ABSTRACT FROM AUTHOR]