In the pre-Hispanic necropolis of Juan Primo, northwest Gran Canaria (Canary Islands, Spain) a grave was found containing a 20-25 year-old woman with a foetus in her abdominal region, whose age at death was estimated at 33-35 weeks of gestation. The purpose of this study is to discuss the possible cause of death of the woman and foetus. Skeletons of both individuals were well preserved, permitting a good record of the bones found in the burial, which is compatible with a pregnancy at preterm. The age of the foetus and the position of the left upper limb raise the possibility that their death was the result of a difficult birth (dystocia). However, a number of alternative disorders can be put forward to explain this death in the third trimester of pregnancy, such as eclampsia and abruption placentae. In this case, pertinent ethnohistorical and osteoarchaeological information about the ancient canaries allows us to assess some of the stressors that would increase their maternal mortality. The lack of similar evidence in archaeological contexts makes this an important finding, providing a likely case of obstetric problems and their impact on pre-industrial societies.