Figure 2:

Blood pressure changes during normal pregnancy.

Figure illustrates blood pressure changes during normal pregnancy (previously known knowledge on the left graph, and current knowledge on the right graph). On the right graph, diastolic blood pressure declined from 12 weeks of gestation (median of 70 mmHg), nadired at to 69 mmHg at 19.2 weeks, and subsequently increased to a maximum median of 78 mmHg at 40 weeks, a difference 9 mmHg from minimum to maximum diastolic blood pressure. Systolic blood pressure declined from 12 weeks of gestation (median of 114 mmHg), nadired at to 113 mmHg at 18.6 weeks, and subsequently increased to a maximum median of 121 mmHg at 40 weeks, a difference 7 mmHg from minimum to maximum systolic blood pressure during pregnancy. These changes in blood pressure differ slightly from prior knowledge (left graph), as it is thought that blood pressure decreases by 10–15 mmHg during mid-pregnancy.