Incidence and predictors of iron deficiency anaemia in parturients undergoing elective caesarean section at a tertiary hospital in New Zealand: a retrospective, observational cohort study.

BACKGROUND: Worldwide, iron deficiency anaemia in pregnancy is a significant problem which can be especially problematic when delivery is by caesarean section, a procedure associated with significant blood loss. Optimising iron stores pre-delivery remains an overarching goal. We aim to measure the incidence of iron deficiency anaemia in patients undergoing elective caesarean section at our institution and determine any associated predictors, as well as adverse outcomes. METHODS: A retrospective, observational cohort study of patients presenting for elective caesarean section over a two-year period. Patient data was collected from hospital electronic records. Iron deficiency anaemia was defined a haemoglobin < 110 g/L and a ferritin < 30 µg/L in the three-month period prior to delivery. The primary aim was to establish the incidence of iron deficiency anaemia at the time of delivery and any associated predictors. Secondary outcomes included any association between the primary outcome and complications defined by the hospital discharge complication coding system, as well as an evaluation of the number of blood tests carried out antenatally per trimester. RESULTS: One thousand and ninety-three women underwent caesarean section over the study period and 16.2% had iron deficiency anaemia. Patients with iron deficiency anaemia were more likely to be of Maori and Pacific Island ethnicity, have a greater booking body mass index, be younger and have a greater parity. Pre-operative anaemia was associated with a greater likelihood of post-operative blood transfusion. CONCLUSIONS: There remains potential for optimisation of iron deficiency anaemia in our local population undergoing elective caesarean section.

The interaction between pre-operative anaemia and peri-operative blood transfusion on patient outcomes following general surgical procedure: a retrospective review.

AIM: To assess the incidence of pre-operative anaemia in patients presenting for general surgery and determine the relationship between pre-operative anaemia, transfusion and post-operative metrics including length of stay (LOS) and infectious complications. METHOD: A retrospective cohort of 1,186 patients. Stratification into two groups with and without pre-operative anaemia through propensity score matching. Logistic regression was used to determine the relationship between pre-operative anaemia, blood transfusion and infectious complications. RESULTS: The incidence of pre-operative anaemia was 17.4%. Red blood cell (RBC) transfusion was greater in those with PA than those without, 13.1% versus 0.7% (OR 21.7 (2.9-166.7, p<0.001)). In the propensity matched cohort, pre-operative anaemia was associated with an increase in LOS from 2.1 to 3.0 days (p=0.006) and increased infectious complications from 6.4% to 18.4%, (OR 3.3 (1.4-7.7), p=0.004). The risk of infectious complications was amplified in the patients receiving RBC transfusion. After adjustment for transfusion, in patients with pre-operative anaemia the OR for infectious complications became 2.3 (0.95-5.7, p=0.06) for those not transfused and 5.5 (2.0-15.3, p=0.001) for those transfused. CONCLUSION: Pre-operative anaemia is associated with an increase in hospital LOS and infectious complications. When adjusted for transfusion the effect of pre-operative anaemia alone on hospital LOS and infectious complications is not statistically significant. Expeditious investigation and treatment of PA could reduce complications and save resources.