Fetomaternal Haemorrhage and Anti-D dosing in Rhesus Negative Mothers Delivering at Moi Teaching and Referral Hospital

Abstract Background Fetomaternal haemorrhage (FMH) is the entry of foetal blood into the maternal circulation during pregnancy or delivery. If this occurs in a Rhesus-negative woman carrying a Rhesus-positive foetus, there is a risk of the mother being sensitized against the D antigen. The effect is seen in the subsequent Rhesus positive pregnancies, which may result in haemolytic disease of the foetus and newborn (HDFN). To prevent this sensitization, anti-D immunoglobulin is usually given. The dose given varies depending on the amount of FMH and the protocols adopted by different professional authorities. Objectives To quantify the size of Fetomaternal Haemorrhage and determine the average calculated dose of anti-D immunoglobulin required for postpartum prophylaxis in Rhesus-negative mothers delivering at Moi Teaching and Referral Hospital (MTRH), Eldoret, Kenya. Methods This was a cross-sectional study among Rhesus-negative postpartum women enrolled within 2–12 hours after delivery. The sample size of 99 was determined using the Kleihauer-Betke test. Participants were sampled consecutively, while data was collected using an interviewer-administered questionnaire, a clinical records review, and blood sample collections. The association between categorical independent variables and the occurrence of fetomaternal haemorrhage was assessed using Pearson’s Chi-Square test. Fisher’s exact test was used whenever the chi-square assumptions were violated. Results Out of 4,552 deliveries over the study period, 143 (3.1%) were Rhesus negative. Of the 143 women, 99 met the eligibility criteria and were enrolled. The mean age and gestational age at delivery were 26.4 (± 5.4) years and 39 weeks, respectively. Fetomaternal haemorrhage (range: 2.5-20ml) was detected in 35 (35.4%) of the women, 24 (68.6%) of whom had FMH of less than 10ml. The use of 100µg of anti-D immunoglobulin would have been sufficient for 89.9% (89/99) of the Rhesus-negative mothers in whom quantification of FMH was done. Conclusion The prevalence of Rhesus negativity among deliveries in MTRH was 3.1%. FMH of less than 10ml occurred in 89.9% of study participants, thus indicating that the majority of the cases of FMH could have been neutralized by 100µg of anti-D immunoglobulin.