Placental weight ratio affects placental mRNA expression of insulin-like growth factor-I and long isoform of the leptin receptor in Plasmodium falciparuminfected pregnant women

Background and Objectives: Plasmodium falciparum infection during pregnancy is characterised by placental inefficiency caused by infected erythrocyte sequestration. Reduced placental efficiency leads to placental intrauterine adaptation for sustaining fetal growth, which is reflected by changes in the expression of placental genes involved in intrauterine growth regulation. Therefore, we aimed to determine whether the placental weight ratio, an indicator of placental efficiency, affects the placental expression of the components of the insulin-like growth factor axis and leptin signalling pathway in P. falciparum-infected pregnant women. 

Methods and Study Design: A malaria case-only analysis of 50 P. falciparum-infected pregnant women in Timika, Papua, Indonesia, was conducted. The placental mRNA expression of insulin-like growth factor-I, insulin-like growth factor binding protein-1, leptin, and the long and short isoforms of the leptin receptor was measured through quantitative realtime PCR. 

Results: The placental weight ratio exerted a positive effect on the placental mRNA expression of insulin- like growth factor-I (coefficient=6.10, p=0.002) and the long isoform of the leptin receptor (coefficient= 4.73, p=0.015) in malaria-infected pregnant women without fever or chill symptoms. Conclusion: Our results indicate that placental adaptive responses caused by adverse intrauterine conditions in P. falciparum-infected pregnant women vary depending on the presence or absence of fever and chill symptoms.