α+-Thalassaemia and pregnancy in a malaria endemic region of Papua New Guinea

Abstract

The effect of maternal α+-thalassaemia on pregnancy was assessed in the north coastal region of Papua New Guinea (PNG), where malaria is hyperendemic and α+-thalassaemia is extremely common. In a prospective study of 987 singleton hospital deliveries, we correlated maternal α-globin genotype with markers of reproductive fitness (age in primigravidae, gravidity, pregnancy interval and the number of miscarriages and stillbirths), Plasmodium falciparum(P. falciparum) infection of the mother and placenta, maternal haemoglobin, preterm delivery and birthweight. The frequency of the -α genotype in mothers was 0.61. Markers of reproductive fitness were similar in women with and without α+-thalassaemia. Median haemoglobin concentration during pregnancy and after delivery was about 1.0 g/dl lower in homozygous α+-thalassaemia than in women with a normal α- globin genotype (P ≤ 0.001). The frequency of placental P. falciparum infection and systemic malaria infection after delivery showed no consistent relationship to α-globin genotype. The frequency of preterm delivery and low birthweight did not vary significantly according to maternal α-globin genotype. Maternal α+-thalassaemia does not affect reproductive fitness or susceptibility to malaria during pregnancy. Although median haemoglobin concentration was significantly lower in mothers homozygous for α+-thalassaemia than those with a normal α-globin genotype, this did not result in an adverse outcome of pregnancy. © 2006 The Authors.