Maternal anaemia and polycythaemia during pregnancy and risk of inappropriate birthweight for-gestational-age babies: a retrospective cohort study in the northern belt of Ghana

Abstract

Small-for-gestational-age (SGA) and large-for-gestational-age (LGA) births are topical issues due to their devastating effects on the life course which are also accountable for neonatal mortalities and long-term morbidities.ObjectivesWe tested the hypothesis that abnormal haemoglobin levels in each trimester of pregnancy will increase the risk of SGA and LGA deliveries in Northern Ghana.DesignRetrospective cohort study was conducted from April to July 2020.Settings and Participants422 postpartum mothers who had delivered within six weeks prior to the study were recruited through systematic random sampling from five primary and public health facilities in Northern Ghana.Primary outcome measureUsing INTERGROWTH standards, SGA and LGA births were computed. Haemoglobin levels from antenatal records were analyzed to determine their effect on SGA and LGA births by employing multinomial logistic regression after adjusting for sociodemographic and obstetric factors at a significance level of α=0.05.ResultsPrevalence of anaemia in the first, second, and third trimesters of pregnancy was 63.5%, 71.3%, and 45.3% respectively and that of polycythaemia in the corresponding trimesters of pregnancy was 5.9%, 3.6%, and 1.7%. About 8.8% and 9.2% of the women delivered SGA and LGA babies respectively. After adjusting for confounders, anaemic mothers in the third trimester of pregnancy had increased risk of SGA births (aOR:5.56; 95%CI:0.64–48; p<0.001). Mothers with polycythaemia in the first, second, and third trimesters of pregnancy were 93% (aOR:0.07; 95%CI:0.01–0.46; p<0.040), 85% (aOR:0.15; 95%CI:0.08–1.65; p<0.001), and 88% (aOR:0.12; 95%CI:0.07–2.15; p=0.001) protected from SGA births respectively. Additionally, anaemia and polycythaemia across all trimesters of pregnancy were not statistically significant with LGA births.ConclusionThe prevalence of anaemia in each trimester of pregnancy increased and that of polycythaemia decreased as the pregnancy progressed from first to third trimester. Delivery of LGA babies was more predominant compared to SGA babies. While anaemia in the third trimester of pregnancy increased the risk of SGA births, polycythaemia across the trimesters gave protection against SGA births. Healthcare providers and stakeholders should target pressing interventions for anaemia throughout pregnancy, especially during the third trimester.Article summaryStrengths and limitations of this studyData employed in this analysis are from antenatal and/or delivery records of postpartum mothers attending postnatal care services in five major public health facilities in Savelugu municipality of Northern Ghana. Hence, the findings are generalizable to the populations in the entire municipality and its neighbouring districts.The measurement of anaemia and polycythaemia across all trimesters of pregnancy, small-for-gestational-age (SGA), and large-for-gestational-age (LGA) births were based on WHO and INTERGROWTH standards which gives an indication of objective assessment of the effect of these abnormal haemoglobin levels on SGA and LGA babies.This study provides vital evidence on the population-based effect of anaemia and polycythaemia across all trimesters of pregnancy on SGA and LGA babies among larger or several ethnic groups and broader age categories in the municipality.Data employed in the analysis were collected at a certain period of time (thus, April to July 2020), and also from antenatal records, so it could be difficult to draw causal inferences for the effect of anaemia and polycythaemia across all trimesters of pregnancy on SGA and LGA babies. Notwithstanding, the findings provide deep insights for health providers and stakeholders to identify prompt interventions for the prevention and treatment of abnormal haemoglobin levels.