Serial Observations of Glucose Tolerance in Pregnancy and the Early Puerperium

Summary It is shown from a longitudinal study of 540 women that the mean random blood glucose concentration in late pregnancy is significantly lower than in early pregnancy. A modified glucose tolerance test on 412 of these women late in the third trimester of pregnancy showed no significant difference between the mean fasting blood glucose and the value 2½ hours after oral ingestion of 50 g. glucose. When this test was repeated in the early puerperium on 357 of these women the mean blood glucose at 2½ hours postglucose was very significantly lower than the mean fasting blood glucose. Both the mean fasting and the mean 2½‐hour blood glucose were significantly lower in the early puerperium than in late pregnancy. One implication is that glucose tolerance tests of women in the early puerperium may be wrongly interpreted as normal.