Preeclampsia and gestational diabetes mellitus: pre-conception origins?

Preeclampsia (PE) and gestational diabetes mellitus (GDM) are two of the most common medical complications of pregnancy, with risks for both mother and child. Like many other antepartum complications, PE and GDM occur only in pregnancy. However, it is not clear if pregnancy itself is the cause of these complications or it these conditions are caused by factors that existed prior to gestation. In this paper, we hypothesize that although the clinical findings of PE and GDM are first noted during pregnancy, the origins of both conditions may actually precede pregnancy. We further hypothesize that pathophysiologic changes underlying PE and GDM are present prior to pregnancy, but remain undetected in the non-gravid state either because pregnancy is the trigger that makes these pathologies become clinically detectable or because there has been limited prospective longitudinal data comparing the pre-gravid and antepartum status of women that go on to develop these conditions. Rigorous prospective cohort studies in which women undergo serial systematic evaluation in the pre-conception period, throughout pregnancy and into the postpartum are ideally needed to test this hypothesis of pre-conception origins of PE and GDM. In this context, we are creating a pre-conception cohort, involving about 5000 couples who plan to have a baby within six months in Liuyang county in the Chinese province of Hunan. Results from this pre-conception cohort program should be able to provide definitive answer to the question of whether the underpinnings of PE and GDM originate prior to pregnancy. Ultimately, the significance of addressing this hypothesis is underscored by its potential implications for targeted interventions that could be designed to (i) prevent the deleterious effects of PE/GDM and (ii) thereby interrupt the vicious cycle of disease that links affected women and their offspring.