High Blood Pressure

ONE of the commonest medical conditions that affect pregnant women in our set up today is high blood pressure. About 10% of pregnant women, especially those in their first pregnancy, are affected by elevated blood pressure.

What is high blood pressure?
This simply means that the blood pressure is elevated above the expected range. When using the mercury manometer, the machine that measures blood pressure, a ‘systolic’ blood pressure of less than 140, is normal. If ‘diastolic’ blood pressure is measured, and is found to be below 90 then again that is reported as normal. ‘Systolic’ blood pressure is generated when the heart contracts. ‘Diastolic’ pressure is the pressure within the arteries when heart muscles are relaxed. Therefore systolic pressure is always higher than diastolic pressure. Doctors find the diastolic blood pressure a better indicator than the systolic blood pressure. High blood pressure is also known as hypertension.  .

Can one have low blood pressure?
Yes. This occurs when the blood pressure is below the normal range. However, absolute values related to this are difficult to define. Often, a drop from previous values and other clinical signs are required to establish the diagnosis. Low blood pressure is also known as hypotension.

Why is high blood common in pregnancy?
The main reason is the physiological changes that come with pregnancy, which trigger constriction of blood vessels. This means that the heart has to pump harder than usual. The unknown triggers are responsible for release of some chemicals in the blood that affect the way the blood vessels work. The process creates a lot of pressure back to the heart and then the blood pressure becomes elevated.

If there was a pre-existing high blood pressure before a woman got pregnant, it can get worse during pregnancy.

A woman can have other conditions like diabetes which can pre-dispose them to having high blood pressure.

Pregnancy induced high blood pressure is likely to occur after five months of pregnancy. Interestingly the offensive changes start gradually from the time of conception, only that the blood pressure increase may not be high enough to be detected.

When pregnancy-induced hypertension is accompanied by excessive maternal weight gain, presence of protein in the urine and general body swelling, it is known as pre-eclampsia. Pre-eclampsia is a specific condition only related to pregnancy. After pregnancy, the blood pressure goes back to normal. Pre-eclampsia can proceed to become complicated; for instance if it develops into eclampsia.

How is high blood pressure detected?
During pregnancy, the detection of hypertension often happens during regular measurements of blood pressure. The vast majority of persons have no symptoms at all. Every woman who attends antenatal care must have her blood pressure taken. At best when the doctor has a base line; he can determine if the blood pressure has increased. The difference can be significant enough to justify the diagnosis of elevated blood pressure.

Weight gain during pregnancy is another way of detecting potential increase in blood pressure. It is worrying if a woman; gains much more weight than expected. There could be oedema (the swelling of the body) and as this becomes severe, there is a possibility of blood pressure elevation.

Pre-eclampsia is also detected through blood pressure measurement. Further, laboratory investigations indicate presence of protein in urine.

How is blood pressure managed when one is pregnant?
The management is by helping to control the blood pressure until a reasonable time to deliver the baby. The balance between the survival of the baby and that of the mother is critical, whenever a doctor is faced with such a situation. The basic task will be to improve the baby’s survival chances. However, the priority is to always try to save the mother because her life takes precedence. When maternal life is at high risk, delivery is done regardless of foetal maturity.

How does one control blood pressure?
There are many ways of doing this: diet and rest (a mother is advised to reduce physical activities). There are drugs that control blood pressure; those that help improve the maturity of the baby as well as reduce complications to the mother and the baby.

All pregnant women must have a balanced diet but specifically for a woman with blood pressure we expect her to have a diet high in proteins, calcium, and rich in vitamins A, C and E. These help her in regulating her blood pressure.

Do the drugs have side effects on the baby?
The drugs have side effects and the doctor has to select the drugs that have the least side effects on both the baby and mother.

How can one prevent high blood pressure?
The theories behind high blood pressure have not been entirely understood yet and prevention therefore becomes a problem.

Women should attend clinics regularly, as required, and they should have their blood pressure checked and their weight taken every time they go for their antenatal care.

They should be educated on the danger signs of high blood pressure which they ought to know even if they are not attending their antenatal clinics.

If a pregnant woman suspects or gets any danger signs, such as persistent headaches that do not get relieved by use of normal painkillers, swelling of the body, and persistent pain on the upper part of the abdomen, she must seek medical attention immediately. The longer she delays, the more likely the damage she may sustain from elevated blood pressure and the more compromised her baby’s health will be.

Dangers of having high blood pressure?
It can cause damage to the kidneys, liver, eyes and the brain. It can cause severe damage to the blood system and even lead to still birth.

Can high blood pressure lead to a birth defect?
No. Blood pressure cannot cause a baby to be born with a defect. However, it restricts the growth of the baby because it hinders the proper functioning of the placenta and in the process the growth of the baby is restricted-a condition referred to as intra-uterine growth restriction. If it is very severe, the baby might die in-utero.

Are some women more prone to high blood pressure than others?
Yes, looking at the races, blacks are at a higher risk than other races. Heredity factors also influence incidence: if one’s mother has had it before, one has higher risk of getting it. Obese and diabetic women are at also at higher risk. Primi gravida – i.e women with their first pregnancies should also be wary of high blood pressure. Socio- economic status of a woman may also contribute to presence or aggravation of high blood pressure due to factors such as diet and access to medical care.

Can exercise help prevent high blood pressure?
Exercises are good in chronic blood pressure cases and those who have obesity, but may not be necessarily useful in patients who have pre-eclampsia. In fact such patients are advised to have a lot of rest.

Must pre-eclampsia or high blood pressure lead to delivery by C-section?
It’s not a must that a woman with high blood pressure delivers by C-section. If spontaneous labour cannot be awaited, the mother is induced to hasten delivery. The doctor will make an informed decision whether a (-section is necessary, taking also into account other obstetric considerations.

Can induced labour raise the blood pressure?
Yes, blood pressure can suddenly rise during labour and even within 24 hours after successful delivery. Therefore close monitoring is essential during and after delivery.

Often, injectable drugs are given to quickly reduce elevated blood pressure. The patient may also be given medication to help prevent convulsions (eclampsia) if the risk is considered to be high.

END: PG  9 /40-41