Foetomaternal Haemorrhage (FMH): A Case for Routine Screening
This prospective study of parturients at a tertiary health institution in south-western Nigeria aims to identify the incidence, severity and obstetric factors predisposing to feto - maternal haemorrhage (FMH) in our population. The exclusion criteria were haemoglobinopathy and patient's refusal of consent to participate in the study. The prepared slide was processed as in the acid elution test described by Kleihauer - Betke. The FMH was calculated using Mollison formula (Mollison 1972). Baseline data included maternal biodata, blood group, RhD and haemoglobin electrophoresis, route/mode of delivery, duration of labour, obstetric interventions, fetal blood group and birth weight. Data generated were analysed with Statistical Package for Social Scientists (SPSS) version 11 software. Frequency tables, cross-tabulations and correlations were performed. Pearson's correlation was applied to continuous variables, while Spearman's correlation was utilised for discrete variables. Level of statistical significance was set at p < 0.05. A total of 163 parturients were studied, of which eight were multifetal gestations. There were no significant differences in maternal age, parity, estimated gestational age at delivery and birth weight, in both groups of parturients with and without FMH. A total of 17 parturients (10.43%), four of which were multifetal gestations (2.45%), had demonstrable FMH. Large FMH (>15 ml fetal cells) were noted in 10 (6.14%) parturients, of which, four were RhD-negative mothers. A total of 9.8% and 11.5% parturients in the vaginal and caesarean delivery groups, respectively, had significant FMH (p = 0.736). Incidence of large FMH was similar with each of the routes of delivery. Antepartum complications of pregnancy, delivery manoeuvres and episiotomy were not significant determinants of FMH. Multiple gestations, fetal birth weight and complications in labour were significantly associated with risk of FMH. Risk-based approach to management, in RhD negative pregnant women, might lead to under-treatment, with attendant increased incidence of isoimmunisation. At least in all RhD-negative women, the cord blood should be tested to determine the baby's blood group and if RhD-positive, Kleihauer - Betke test should be done to determine the degree of FMH and anti-D immunoglobulin dose administered appropriately. Further studies are necessary to establish the determinants/risk factors for FMH.