Understanding Blood Pressure
Preeclampsia vs. Hypertension
Preeclampsia, a condition which arises in pregnant women who have completed 20 weeks or more of their pregnancy, is characterized by high blood pressure and the presence of protein in the urine. High blood pressure alone is not preeclampsia, but is defined as gestational hypertension. Although gestational hypertension carries risk and is serious, the range of severe problems that are inherent in preeclampsia do not appear in gestational hypertension.
If there is an increase in blood pressure compared to the first visit, and it occurs after 20 weeks of pregnancy, with a blood pressure reading of over 140/90, or a rise of 25 or more in the systolic blood pressure (the first number) or more than 15 in the diastolic blood pressure (the second number), the doctor is warned there is a possibility of preeclampsia.
Defining Blood Pressure Measurement
Two numbers define blood pressure reading, the higher number (which appears on the top of the equation) is the measurement of systolic blood pressure. This number indicates the maximum amount of pressure of the blood within the blood vessels of the circulatory system. The highest burst of pressure happens when the blood is forced into circulation by the contraction of the heart as it beats. The lower number (which is on the bottom of the equation) is the amount of pressure in between beats of the heart. The number shows how much blood is in the vessels. When presented, the number is 120 over 80 or 120/80. While there is no such thing as one specific blood pressure that is considered normal, there is a range which is considered normal.
There Are Many Variables
There are many variables when it comes to measuring blood pressure. A person's blood pressure may vary greatly throughout the day. It is affected by the individual's age, their sex, their activity level, stress levels and exercise, sleep, and, pregnancy.
A blood pressure reading of 120/80 is common for someone who is not pregnant. When not pregnant, a woman's blood pressure is considered to be high if it is taken several times when she is at rest and the numbers go above 140/90. The person's age, health and status is terms of medication are all factors that are considered when assessing blood pressure.
How Pregnancy Affects Blood Pressure
When a woman is pregnant, her body releases a variety of hormones that have a relaxing effect on the blood vessels, thus lowering blood pressure. When circulation is constricted, the blood strikes the walls of the blood vessels at a higher pressure causing a rise in the measurement. When they are relaxed and softer, the measurement of blood pressure is lowered. Because of this, a blood pressure reading of 90/60 is not uncommon in early pregnancies. While blood pressure varies in pregnancy, there is a range of readings that indicate whether a woman has reacted to the hormone changes due to pregnancy.
Timing of measuring blood pressure as it relates to the number of weeks gestation is another important factor.Changes in blood pressure during the early, mid and later pregnancy, falling from the first to about 24 weeks where it remains low until about 36 weeks. Then it may rise in the weeks before birth. Stress or activitiy usually do not affect the numbers nor cause them to rise in a pregnant woman, an unusual feature of blood pressure during pregnancy.