Pregnant women (n = 19: n = 10 healthy pregnant and n = 9 GDM pregnancy) were recruited at the time of their routine examination for glucose intolerance between the 24th and 28th weeks of pregnancy (median gestational age: 25 weeks and 6 days; median age: 34.5 years). Healthy non-pregnant controls matched for age (n = 10) were recruited at the Blood Bank of the Swiss Red Cross, Basel. Human placentae were obtained from pregnant women who delivered healthy, singleton infants at term (>37 weeks’ of gestation) undergoing elective cesarean section.