Definition of Blood Pressure
The blood pressure is the force exerted against the arterial walls, dependent on the energy of the heart action, the elasticity of the walls of the arteries and the volume and viscosity of the blood. The two types of pressure measured are:
· Systolic - This pressure occurs during heart contraction and is found at it's maximum pressure near the end of the stroke output of the left ventricle of the heart. The blood leaves the ventricle and is pumped through the parts of the body. When a reading is taken, this is the top number (e.g., the 140 in a 140/90 BP reading - and read as "140 over 90").
· Diastolic - This pressure occurs when the heart is at rest and relaxes and is found at it's minimum pressure, filling with blood before the next contraction. This is the lower or bottom number (e.g., the 90 in a 140/90 BP reading).
· The units in which BP is measured is "mmHg", meaning millimeters of mercury.
The BP reading is an evaluation of how hard the heart must work in order for the blood to adequately circulate throughout the body. Pathologically high blood pressure (hypertension) is a serious concern that may represent or signal an underlying "disease" problem in the body. High BP may contribute to or help bring about cerebral hemorrhage, cardiac arrest, headaches, visual problems, etc. In pregnancy, it is associated with convulsions, toxemia (eclampsia), and abruptio placentae.
However, it cannot be assumed that hypertension (high BP) appearing in pregnancy is always a problem.
A normal, healthy person's BP changes constantly and can vary 30 to 50 mmHg due to exercise, activity, rest, temperature, time-of-day and nervousness, anxiety or stress levels. A simple visit to a physician's office for a blood pressure check can raise the BP reading by 15 to 20 mmHg due to "doctor's office anxiety". It is important to know the client's regular "at home, relaxed" blood pressure.
In pregnancy there is a drop in blood pressure in the second trimester followed by a rise in the third. This is related to normal blood volume expansion and is entirely physiological, not pathological. In a well-nourished woman, the blood pressure may vary a great deal and not reflect any increased risk to mother or baby.
Checking Blood Pressure Accuracy
A variety of blood pressure instruments are available and it is best to try different types to see which suits you and the client best. Some have a stethoscope attached, if not a stethoscope will be required. If a arm cuff is used, it is essential that appropriately sized cuffs are available for the age and size of the client (arm size ranges are child 7.24-10.51 inches, Adult 10-15.98 inches, and large adult 13.5-20 inches... check specific manufacturers sizing for differences). This is essential for accurate readings. Digital cuffs, wrist BP cuffs and finger attachments are also available.
Hypertension in Pregnancy
Pregnancy induced hypertension (PIH) is one of the latest modern obstetric redefinitions and is the current symptomatic diagnostic criteria for metabolic toxemia (since it has been proven that it is not edema or weight gain). The symptom is being seen as the problem without regard as to why the symptom is there or what it may mean to the individual pregnant woman.
The current diagnosis of hypertension has been used since 1972 and is defined as: an elevated blood pressure (BP) with a reading as any rise systolic pressure of 30 mmHg or more and/or a rise in the diastolic of 15 mmHg or more above baseline.
Prior to 1972, the definition was a pressure of 140/90 or higher on any two occasions six hours apart. The redefinition of hypertension in pregnancy places many healthy women into a new "high-risk" catagory.
Remedies For Benign Hypertension
· Relaxation Techniques - This includes Yoga, meditation, visualization, deep breathing and tension reducing methods. These should be done several times daily and modified lifestyle as much as possible to reduce stress and anxiety.
· Moderate exercise and fresh air can be very beneficial. Bedrest, on the other hand, is useless even though widely recommended by medical professionals.
· Raw garlic, parsley and onions eaten in large quantities can help reduce high blood pressure. Garlic oil capsules 2-10 daily have helped some women. Be sure of your source if taking over the counter, manufactured brands in bottles.
· Juice taken from 1/2 lemon or lime mixed with 2 teaspoonfuls of cream of tartar in half a cup of water can be taken once daily for 3 days. This remedy can be repeated once after a rest of 2 days.
· Tea made from hops (1 tsp to 1 cup boiling water, steeped for 20 minutes) can be safe and effectively used during the last 4 mos of pregnancy. Hops can be ill-tasting to some. Note: Hops should not be taken during the 1st trimester of pregnancy.
· Passionflower tincture (15 drops, 3 times daily) or capsules (2-4 capsules daily) is useful for high benign BP. Take for several weeks to obtain the best result.
· Skullcap herbal infusion (1 oz. to 1 quart boiling water, cover and steep 4-6 hours) and drink 1 to 2 cups daily to build up and strengthen the nervous system.
· Hawthorn berries will work cumulatively as a cold infusion (1 oz. crushed dry berries in 2 cups of cold water steeped overnight, brought quickly to a boil, strained and sipped. One cup daily should be taken. A tincture dose is 15 drops 2 or 3 times daily. Hawthorn berries strengthens the heart and is said to help cure (and possibly prevent) congenital heart defects. The more taken the better the remedy works.
Interpreting Blood Pressure Readings
Prenatal care should be started as soon as possible to obtain a relative baseline of vital signs. The midwife should always ask what the normal pre-pregnant blood pressure is for a birthing client.
· Low blood pressure (hypotension) readings are often found in young women, women who exercise regularly, and vegetarians. Symptoms of low BP include nausea, dizziness on rising, fainting, visual disturbances and breathlessness with exertion. These symptoms can be remedied by rising slowly and correcting hypoglycemia if the problem is low blood pressure.
· Benign blood pressure elevations in a well-nourished, well-hydrated woman may be due to:
o Multiple gestation with the extra blood volume causing a normal rise in BP.
o Technical errors by midwife or assistant. Recheck BP later in prenatal visit.
o A lack of sodium in an otherwise well-nourished, well-hydrated woman can cause edema and high or elevated BP. Be sure she is sea-salting food to taste and using more if she is sweating and/or during hot weather.
o Obesity is often associated with high bp readings due to inaccurately sized bp cuff. Be sure to have an appropriately sized bp cuff.
o Maternal stress or anxiety may also effect blood pressure, causing a rise. Some women have "labile" BP, which means they have "rapidly changing" blood pressure. Readings will rise significantly when they are stressed or have anxiety. Sometimes this will manifest during medical examinations (called white coat hypertension), during an exceptionally busy or hectic day or with excitement. If this occurs, then the midwife should wait until later in the prenatal or labor visit to do the BP check, allowing the woman to relax before the blood pressure is taken. If high, retake again later with the woman in a reclining position. A decline in BP is usually seen at this time. If not, choices can be made by the midwife to either not worry about it since the woman's diet is good or a relative can retake the blood pressure at the woman's home and relay the information to the midwife. This latter choice will often reveal a lower blood pressure reading than was seen during the midwife's visit.
Essential hypertension may pre-exist pregnancy or may reveal itself during pregnancy. This may be a manifestation of repeated blood pressure checks during visits and possible anxiety from having it checked frequently (much more often than when the woman is in a healthy, non-pregnant state). Essential hypertension results from no known cause and commonly appears with age. Young black women will often exhibit this type of hypertension. Usually this type of hypertension is managed with hypertensive drugs, and in pregnancy with low sodium, low calorie diets and diuretics. Such medical management has led to a higher risk catagory and poor outcomes for these women. Recent studies have shown that undrugged and unrestricted hypertensive women can and do grow big, healthy babies having healthy placentas. They are not considered high risk on a proper nutritional diet adequate in protein, calories and nutrients for pregnancy.
Serious Causes of Hypertension & Underlying Problems
Metabolic Toxemia - Pre-eclampsia/eclampsia: This pregnancy-induced health problem is a serious complication which can be preventable with a good, nutritious diet. If the woman has been eating well and salting adequately and her fluid intake has been good than this is not a concern. However, if the diet has been lacking, then it will need immediate attention. Increasing her sodium, protein and fluids to appropriate levels will prevent further intervention and relieve current symptoms. If the woman is having digestive and assimulation problems such as nausea, vomiting, diarrhea, or pre-existing colon or stomach trouble or has an unrecognized liver weakness from a previous disease, then these things need to be corrected so she can maintain a healthy pregnancy.
The physiology of toxemic hypertension is the body is trying to adequately nourish an extra organ (the placenta) without sufficient blood volume to do so. Pressure rises in an attempt to compensate while vessels constrict as edema causes pressure. A concentrated blood volume and poor prostaglandins production may cause abnormal platelet aggregation in the vessels increasing BP more. Headaches and blurred vision are symptoms of pressure in the brain and often precede convulsions. Abruption may occur as pressure pushes a poorly attached placenta away from uterine wall.
1. The midwife should advise the client on signs and symptoms of increasing severity of pre-eclampsia (epigastric pain, severe headache, blurred vision or stars, edema of the face, hands and ankles, convulsions).
2. The midwife should consider appropriate baseline labwork particularly if there is a history of pregnancy induced hypertension (PIH) or preeclampsia. Tests may include:
· Routine urine "dipstick" analysis for protein and glucose at each prenatal visit. If protein is found, it is important to exclude a urinary tract infection (UTI) which may be present in spite of the lack of symptoms.
· Urine microscopy & culture. This is done when protein has been found in the urine to exclude UTI. A midstream specimen with a bacterial count of less than 100,000/mm3 are unlikely to indicate active infection, especially if a significant white-cell count is not found in the urine. Bacterial counts between 10,000 and 100,000/mm3 are of borderline significance and a further urine sample should be obtained.
· Serum urea and creatinine. The lower levels of serum urea and creatinine in normal pregnant women compared with non-pregnant clients/patients reflect the increased glomerular filtration rate which occurs during normal gestation. In PIH, especially if associated with proteinuria, the serum levels are higher than in normal pregnancy although usually within non-pregnant range. Levels above this range suggest underlying chronic renal impairment either as a cause or as a result of pre-existing hypertension. An acute rise in blood urea may occur in acute renal failure which sometimes accompanies eclampsia.
· Serum electrolytes. Serum sodium and potassium concentrations are generally lower in normal pregnancy than in normal non-pregnant women. The administration of potassium-losing diuretics will aggravate this.
· Serum uric acid. Like the blood urea, this is lower in normal pregnant women than in non-pregnant women due to the increased renal clearance. It is usually raised in the stage of pre-eclampsia, and a rising level in a woman with high blood pressure in the last trimester may be an indication of impaired fetal outcomes.
· Blood film and platelet counts. The hemoglobin should be checked frequently in a pregnant woman. If she is severely hypertensive and has symptoms of severe pre-eclampsia there may be evidence of reduced platelets, increased reticulocytes and abnormally shaped red blood cells.
3. A complete prenatal check should be performed. Based on results of this prenatal:
· High BP with no symptoms of pre-eclampsia, advise client to assume left lateral lying position 3-4 times daily for 30 minutes for 2 days. Review diet and lifestyle, and recommend complimentary therapies. If the blood pressure is still elevated, the woman should consult with her health care provider.
· If high BP is accompanied by signs and symptoms of pre-eclampsia such as significant proteinuria, weight gain greater than 3 lbs in one week, and/or edema or other symptoms.
a. The woman should advise her health care provider immediately, she may anticipate possible hospitalization and IV therapy, bed rest and additional labwork.
b. The midwife should advise client to increase fluids and dietary protein.
Kidney Disease: cysts and tumors can cause elevations in BP. If a woman knows she has a history of kidney problems, she should be checked by a renal specialist before becoming pregnant. If it is suspected during pregnancy, be sure an accurate differential diagnosis is made. Toxemia used to be thought to be a kidney malfunction because symptoms are similar on the surface. If there is current infection, a herbal cure is Uva Ursi leaf infustion (1 oz. to 1 quart boiling water steeped at least 8 hours, covered) taken 2 cups daily for 10 days. Drink unsweetened pure cranberry juice (not the frozen or bottled kind found in the usual supermarkets which is mostly sugar and only about 10% or so of actual cranberry juice) and increase vitamin C to further help clear infections. To build and strengthen damaged kidneys, Nettle leaf infusion (1 oz. to 1 quart boiling water and steeped 4-6 hours) can be taken. Drink 2 cups daily or as desired throughout pregnancy.