Feto-maternal outcomes of women with Rhesus iso-immunization in a Nigerian tertiary health care institution.

Abstract

Background: Fetomaternal haemorrhage may occur during pregnancy or at delivery and may lead to allo-immunization to the D antigen if the mother is Rhesus (Rh) negative and the baby is Rh-positive. Objectives: To determine the incidence, socio-demographic characteristics and pregnancy outcomes of Rh negative pregnant women in a Nigeria Tertiary health care institution. Methods: A review of the clinical records of all Rh-negative pregnant women, managed at the Nnamdi Azikiwe University Teaching Hospital (NAUTH), Nnewi, South-east Nigeria between 1st January 2009 and 31st December 2013 was done. Data were entered into Excel Spread sheet and analysed using computer Epi-Info 2013 version 7. Results: There were a total of 5561 deliveries and 117 Rh negative pregnancies during the period, given an incidence of 2.1%. Of the 117 Rh negative pregnancies, only 89 (76.1%) case files were available for analysis. Majority, 55.1% of the women were of ABO Blood Group O while ABO blood group discordance occurred in 33.7% of male partners. Seventy-one (79.8%) of the women have had previous pregnancies and only 33(46.5%) of these received anti-D prophylaxis in the previous pregnancies. Sixty-three (70.8%) of the pregnancies were booked and 48 out of 63 (76.2%) of them booked after 20 weeks of gestation. Indirect Coombs test was done in 61 out of 63 (96.8%) women that were booked but only one (1.6%) woman tested positive. None of the women had a follow-up testing. Only the woman that tested positive for indirect Coombs test had her antibody titre subsequently determined. Forty-five (50.6%) pregnancies were carried beyond date while 88.5% of the women that had postdate were delivered via caesarean section (p<0.001) with the commonest indication being fetal distress (42.9%). Sixty-one (68.5%) babies were tested post-delivery while 49 (80.3%) of 61 babies were rhesus incompatible with the mother. Only 40 (81.6%) of the incompatible mothers had Rh anti-D immunoglobulin administered after delivery. Neonatal jaundice occurred in 21.3% of the babies. There were 14 (15.7%) perinatal deaths. Conclusions: The incidence of Rhesus negative pregnancies was 2.1% while Rh isoimmunization rate was 1.6% and the uptake of Rhesus Anti-D immunoglobulin is suboptimal. Rh negative primigravida?s tend to be unbooked and had significantly higher still births than their multigravid counterparts. Rhesus negative pregnancies carried beyond their dates had a significantly higher caesarean section rates than those delivered at term or before the expected date of delivery. There is need for further studies to clearly explore these trends.