Hypertension during pregnancy
Sunday, March 10, 2019

Hypertension, or high blood pressure, is a chronic disease, increasing in prevalence globally due to multiple reasons. If present during pregnancy, it poses a grave threat to the health of both the baby and mother.

About 60 per cent of women may develop high blood pressure only during pregnancy, which will settle after delivery. In case of women hypertension before pregnancy, it can be aggravated during the prenatal period.  Some women tend to develop high blood pressure with every pregnancy. In some, it may be present during a pregnancy but normalises after giving birth. Complications related to high blood pressure are likely to be more when it is present during pregnancy.

Pre-existing high blood pressure can be aggravated during pregnancy because greater volume of blood flows inside the body and at a slightly higher pressure. This can lead to sudden heart or kidney failure. Some women develop sudden swelling over the feet, and high blood pressure and convulsions, when pregnant—a condition called eclampsia. This is a medical emergency.  The blood pressure is brought down immediately and the foetus is evacuated, otherwise the mother can die.

Hypertension during pregnancy can lead to death of the baby inside the mother’s womb, necessitating induction of labour or operative removal of the dead baby depending on the stage of pregnancy. This is troublesome as well as   painful for the woman.

A woman who has pre-existing hypertension has to continue her antihypertensive medication when pregnant. Some of these drugs have the potential to cause damage to the unborn baby, particularly when taken during the first three months, when the baby’s body is being formed. Sedative drugs like diazepam are sometimes used as adjunct therapy to control high blood pressure. But during pregnancy, it can harm the foetus.

Associated diabetes can aggravate these problems. Women who smoke or take alcohol are more prone to develop high blood pressure and its related complications during pregnancy.

Very young mothers, i.e. teens, or those who conceive after the age of 40 are said to be more susceptible to develop high blood pressure during pregnancy. Similarly, obese women are also at high risk for hypertension when pregnant. Twin pregnancy (i.e. when twins are present in uterus)   poses a threat for the woman to have high blood pressure.

When a woman conceives, it is important for her to have her blood pressure checked at regular intervals. Thus, hypertension can be detected and treated at the earliest before any complications develop.  Checking the blood sugar regularly for diabetes is also useful, because both can co-exist and one can aggravate the other, thus    augmenting the risk of damage to the mother and baby.

Testing the urine for passage of protein is an important antenatal test done and is more useful for women suffering from hypertension. This helps in detecting any damage to the kidney at the earliest and also in diagnosing eclampsia.

If a woman is overweight, she should adopt measures to reduce the body weight and prevent high blood pressure. Brisk walking is by far the most suitable exercise for a pregnant woman. This should be combined with a low or fat free diet, which can help in preventing or reducing obesity.

Smoking and alcohol should be totally avoided.  Apart from causing hypertension, these toxic substances have various other harmful effects during pregnancy.

A previously known hypertensive patient should inform her doctor and take medicines to lower the blood pressure during the first three months, on medical advice. This can avoid the potential damaging effect of drugs on the unborn baby. Specific drugs are needed for hypertension during pregnancy.

Thus, overall management of a pregnant lady with hypertension becomes slightly different from a non-pregnant person. For the sake of her unborn baby and herself, a woman should be careful about her blood pressure.