A biobank resource for placental malaria and placental health research

Background Malaria during pregnancy is a serious threat to maternal and child health in malaria-endemic regions. Malaria during pregnancy often leads to placental malaria, which has severely detrimental effects on fetal outcomes, including fetal growth restriction, preterm delivery, and stillbirth. However, the mechanisms by which placental malaria causes adverse outcomes remain poorly understood. Crucially, there are no tools for detecting and/or intervening in placental malaria during pregnancy. This is mainly because the placenta is inaccessible to research during pregnancy. Nonetheless, its accessibility after delivery offers unique opportunities for studying placental diseases. To support such research, collecting and biobanking naturally-infected placental samples in the geographical context in which diseases of interest occur is crucial. Methods Here, we describe the establishment of a biobank of samples obtained from a malaria-endemic region of Kenya, which aims to enhance research capacity in this important but under-studied health challenge. Histology, PCR, and isothermal identical multirepeat sequence PCR were used to determine the placental malaria status of biobank samples. Results Our biobank characterization indicates that placental malaria affects most pregnancies in the malaria-endemic region, despite mothers being asymptomatic during pregnancy and having received anti-malaria chemoprophylaxis. Of the techniques used to detect placental malaria, isothermal identical multirepeat sequence PCR detected the highest number of placental malaria-positive samples (54.2%), compared with placental histology (37.3%), and placenta tissue PCR (17%). However, results from the various techniques did not overlap fully. Conclusion Our observations highlight the need to rigorously characterize placental samples from malaria-endemic regions, including by using multiple complementary techniques, even in cases of undetectable malaria during pregnancy. It may also be beneficial to obtain samples from non-malaria-endemic regions for use as placental malaria-naïve controls.