The normal, healthy person's blood pressure changes constantly with activity, rest, and anxiety levels. For instance, laughing or talking can elevate the diastolic pressure as much as ten points. In pregnancy, there is generally a drop in blood pressure in the second trimester followed by a rise in the third. This fluctuation is related to normal blood volume expansion and is entirely physiological. In a well nourished woman, the blood pressure may vary a great deal and not reflect any increased risk to mother or baby.

The next paragraph now reads Proper positioning and other considerations: It is best to avoid coffee and smoking at least 30 minutes prior to taking a reading. Have the woman rest quietly at least 5 minutes before you start. Note that tight clothing above the cuff or crossed legs may falsely elevate the reading. The blood pressure should be taken with the person sitting quietly with their back supported and their arm supported at heart level, palm up. If the arm is hanging to the side, the reading could be artificially elevated as much as 8 mmHg. If no resting surface is available, position yourself so that you can support their arm with your arm or leg. Both feet should rest comfortably on the floor. If the woman is lying supine, it is best to place her on her side (left is best) so you do not encourage supine hypotension (the artificial lowering of blood pressure from the uterus pressing into the large vessels in her back). Her arm should rest flat, parallel with her body. Note on the chart how the woman is positioned (this will only be necessary if she is positioned differently than is usual for your practice.)