Topic: High Blood Pressure, Pre-eclampsia and Caesarean Section. My name is Debby Miller. I am a thirty something mother of two boys. One born by caesarean and the other a VBAC. I work full time as a financial adviser in a Government Department and am currently studying two degrees; Accounting and Human Resource Development. From my work and study I have developed a good ability to research things. A skill that was particularly helpful to me when I was researching for my VBAC birth. I have a great interest in birth issues, particularly related to being an informed patient because of my first bad birth experience and my subsequent good one. I have offered to write a series of articles about a variety of subjects for Birthrites in the hope that my experiences and investigative abilities can help other mothers and mothers to be to make informed decisions about their birth choices. The topics I intend to write about are shown in the Discussion Topics Index. I will not be writing them in any specific order or to any specific time frame. I would advise all readers to read the first article Believing What You Are Told as this provides the basis for you to understand how assessments are made, both by myself and in the references I use, on the remainder of the topics discussed. I will try to keep the articles simple and will provide examples where possible. If medical terms are used I will add them to the Glossary so you can see what they mean. I would ask that readers note that I will try to keep the research factual and not input my own personal bias, however whilst I am aware of my own prejudices, I will probably lean towards documentation that supports my view. Secondly I am not a medical practitioner, nor do I have any medical training. The information I present will be based on research, journal articles and texts, and my interpretation of those. I will quote all references. Women wishing to use the information I provide are recommended to read the references for themselves and should discuss any issues pertaining to their own medical management with a qualified medical practitioner or midwife. Topic: High Blood Pressure, Pre-eclampsia and Caesarean Section What is High Blood Pressure? What is Pre-eclampsia? Some rise in blood pressure in late pregnancy is normal and without other symptoms, it is thought that it may initially be a compensatory mechanism to fetoplacental hypoxia and is therefore a physiological reaction. In some women this compensation mechanism breaks down and the resulting multisystem disease is reflected by pregnancy induced high blood pressure and pre-eclampsia (ref 19). Pre-eclampsia can can be mild or severe:
What are the Symptoms of Pre-eclampsia? Pre-eclampsia is a disease that gets progressively worse over time and the only sure cure is delivery of the baby. The key symptoms are high blood pressure and protein in the urine however the following may also be symptoms:
Pregnant women with these symptoms should seek immediate medical advice because they could be at risk of further complications including:
It should however be noted that some swelling of the feet and ankles is normal in pregnancy (ref 2 , 14 & 20). There is no single test that can diagnose pre-eclampsia however the key indicators are increased blood pressure and protein in the urine. The other symptoms are secondary signs as they can also be caused by conditions other than pre-eclampsia and some can occur in a healthy pregnancy. Pre-eclampsia is usually confirmed with blood tests that can detect the signs of the condition (ref 1). Is High Blood Pressure That is Not Pre-eclampsia a Problem? High blood pressure can harm the mothers internal organs, cause low birth weight in the baby and may cause premature delivery. (Ref 1) Does High Blood Pressure Always Lead to Pre-eclampsia? High blood pressure is considered mild if the top number is between 140 and 160 and if the bottom number is between 90 and 110. And there is argument that mild high blood pressure does not benefit from treatment (Gabbe, 1996). The risk of a woman who has high blood pressure developing pre-eclampsia is between 5% and 52%. In the study by Gabbe (1996) it was found that only 4.7% of women with mild high blood pressure went on to develop pre-eclampsia. He stated that:
Who Gets Pre-eclampsia? General Increased Risk. The people who are most at risk of getting pre-eclampsia are:
Pre-eclampsia cannot be predicted accurately (ref 1). Genetic Risk. There is some belief that genetic factors may play a part in increasing the risk of pre-eclampsia, and these risks are not confined to the mother. One study by Lie et al concluded that both the mother and baby contribute to the risk of pre-eclampsia with the contribution by the baby being affected by the genes it has inherited from its father. If the childs father has previously fathered a pre-eclamptic pregnancy in a different woman then the new mother's risk of developing pre-eclampsia is 1.8 times above average (ref 16). Birth Gap Risk. The study by Conde-Agudelo and Belizan found that the incidence of women who had pre-eclampsia was greater amongst those who had inter-pregnancy gaps of less than 6 months or greater than 59 months, and there were more adverse outcomes in these two groups (ref 18). Who Gets Eclampsia? One study in England sited the incidence of eclampsia as being 1/2040. Eclampsia cannot always be predicted, in this study it was found that 38% of eclamptic episodes occurred in women with no documented history of high blood pressure or protein in their urine. Of the women who did suffer from eclampsia 40% occurred post-partum (after delivery), more than a third (38%) ante-partum (before birth), and the remainder (18%) intra-partum (during delivery). The ante-partum pre-eclampsia was found to be the most dangerous for mother and baby. (ref 15). Women who are at increased risk are first time pregnancies, teenage pregnancies or mothers older than 40 years, African-American women, multiple pregnancies, and women with a history of diabetes , hypertension, or renal (kidney) disease (ref 3). If I Had It Before Will I Get It Again? How Can Women with High Blood Pressure Prevent Problems During
Pregnancy? Risk can be reduced prior to pregnancy by controlling blood pressure through diet, regular exercise and maintaining an appropriate weight (ref 1). Risk can be reduced during pregnancy by obtaining regular pre-natal care, regular light exercise and avoiding alcohol and tobacco (ref 1). Women should also be aware of a condition called "White Coat Hypertension". This is where the mother exhibits high blood pressure when she is in the doctors surgery or hospital but at other times her blood pressure is normal. The paper by Dr T Pickering states that research indicates that as many as 20% of women fall into this category (ref 4). To exclude the possibility of "White Coat Hypertension" in pregnancy it is recommended that women be checked by use of an ambulatory blood pressure monitor for 24 hours. This gives an estimate of the true level of blood pressure in daily life. Several studies have shown that the prediction of risk in an individual patient is more closely related to the ambulatory pressure than to the doctor's readings (ref 4). It was found in the study by Dr Pickering that only 7% of women with "White Coat Hypertension" had protein in their urine compared with 62% of women will consistent high blood pressure. However these women were generally treated for delivery purposes the same as women with consistent high blood pressure with a caesarean rate of over 40% compared to that of women with consistently normal blood pressure - 12%. Dr Pickering indicated that women with "White Coat Hypertension" were placed at a significantly higher risk of an unnecessary caesarean as a result of a failure to confirm true high blood pressure (ref 4). Why Is Pre-eclampsia a Concern? Pre-eclampsia may also lead to eclampsia and it cannot be predicted which women will go on to develop this more severe condition. The degree of high blood pressure and protein is not a predictor of whether a woman will develop eclampsia (ref 3). Pre-eclampsia affects both the mother and the baby. It has a direct affect on the placenta which affects the growth of the baby and can affect the mother's kidneys, liver and brain. If it develops into eclampsia the mother will have seizures and it can result in the death of the mother and/or baby. Pre-eclampsia / eclampsia is the leading cause of fetal death in the US and UK (ref 1, 3 & 20). There is some debate that high blood pressure and pre-eclampsia during pregnancy can cause long term problems, however this assertion is disputed in other studies (ref 1&17). Can Pre-eclampsia be Treated? Some of the methods of treating high blood pressure and/or pre-eclampsia are detailed below. Mineral Supplements. From a study into mineral supplements as a means of lowering high blood pressure Dr F. Sacks has indicated that a potassium rich diet or potassium supplements does act to lower blood pressure. The study found that magnesium and calcium supplementation did not lower blood pressure and could actually interfere with the blood pressure lowering effect of potassium (ref 7 & 14). (If food supplementation is being considered as a control to blood pressure in pregnancy it should only be done in consultation with the ante-natal care provider). Vitamin Supplements. One study showed that supplementation with vitamin C and E could reduce the risk of pre-eclampsia. In the study only 8% of high risk women treated with vitamins C (1000mg) and E (400IU) developed pre-eclampsia compared to 17% of the group of women who were given a placebo (ref 10). (If food supplementation is being considered as a control to blood pressure in pregnancy it should only be done in consultation with the ante-natal care provider). Plasma Volume Expansion. There is insufficient evidence for any reliable estimates of the effects of plasma volume expansion for women with pre-eclampsia (ref 8). Aldomet. This is a drug that has been shown to be safe long term for both the mother and the baby in the treatment of high blood pressure in pregnancy (ref 9). Baby Aspirin. There has been some suggestion that baby aspirin can be of benefit to women with high blood pressure (ref 9). A review of studys conducted by Duley et al found that, anti-platelet drugs, which is generally low dose aspirin does have a small to moderate benefit in the prevention of pre-eclampsia. The review concluded that a 15% reduction in the risk of pre-eclampsia and an 8% reduction in the risk of preterm birth (ref 11). However the contrary view has also been put across. One study quoted by Dr S Caritis indicated that there was no benefit in giving aspirin to women deemed high risk for pre-eclampsia. The study quoted indicated that about 20% of high risk women got pre-eclampsia whether they took the aspirin or not. It should however be noted that this study is earlier (1998) than the collective review conducted by Duley et al (ref 12 & 14). Magnesium Sulphate. Only one reference to the use of this drug was found and it indicated that more studies were required before it was used to treat pre-eclampsia (ref 13). Ref 14 highlights some of the concerns with the use of magnesium in particular side affects and magnesium toxicity. Exercise and Rest. Light exercising, such as walking, with the approval of the doctor may be of some benefit. Regular periods of rest throughout the day, preferably lying on your LHS can also be of benefit. There is some belief that this can increase the birth weight of babies who are at risk of intrauterine growth restriction (ref 9 & 14). Epidurals in Labour. Several suggestions have been made on how pre-eclampsia can be treated, particularly during labour. One of the most common is the use of epidurals during labour, as lowered blood pressure is a common side effect of epidurals. However in the study by Lucas etal, it was found that epidurals provided no therapeutic benefit to women with pregnancy induced high blood pressure (ref 5). Hogg et al, confirmed that for women with pre-eclampsia who did want to use epidural anaesthesia that it was safe to do so, and their study indicated that the risk of caesarean was not increased by this choice of pain relief. (It should be noted that this point is contrary to the findings of many study's that do demonstrate a relationship between epidurals and increased risk of caesarean.). It was however noted that women with pre-eclampsia were more likely to have a caesarean as a result of their medical condition (ref 6). Do I Have To Have a Csec If I Have Pre-eclampsia? As the only "cure" for pre-eclampsia is delivery then women with severe pre-eclampsia are more likely to have early induction or delivery. The further on the pregnancy is the more likely it is that the preferred initiation of delivery will be induction rather than caesarean. An induced delivery will also be subject to a higher degree of monitoring, both because of the induction and because of the medical condition of the mother. Both these factors do serve to increase the risk of having a caesarean, and this is reflected by the over 40% caesarean rate in pre-eclamptic mothers (ref 4, 20 & 23). Can I Still Have a VBAC If I Have Pre-eclampsia? The only point to be conginscent of is that the pre-eclamptic mother has an increased risk of being induced, and there are a number of studies which show a correlation between induction and increased risk of uterine rupture (see previous Birthrites articles). This would indicate that where an early delivery is required that the mother should discuss the method of induction with the doctor so as to minimise her risk, if she felt this risk was of significant concern to her. ===================================== Bibliography
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