Hypertension in Pregnancy

Hypertension in Pregnancy

One theory is hypertension in pregnancy is an abnormal reaction to the increase in blood volume during pregnancy. The blood vessels are supposed to dilate in order to accommodate the increase, but sometimes this process doesn’t happen correctly. A moderate rise in pressure isn’t harmful, but a severe rise can be dangerous. An average blood pressure is about 120/70, and doctors generally aren’t too concerned if the bottom number, or the diastolic measurement, increases by only ten or 15 points. However, if a woman already has a higher-than-average blood pressure, a moderate rise might mean that her numbers become worrisome.

A blood pressure measurement is part of every prenatal visit. Hypertension in pregnancy may damage the way the placenta functions, making it work harder to transfer oxygen and nutrients to the fetus. The baby may become malnourished and grow more slowly than usual. This process is called IUGR or Intra Uterine Growth Restriction. High blood pressure is also associated with Placental Abruption, which is a very serious condition where the placenta detaches from the uterus before the birth of the baby. Women with high blood pressure might need medication to keep their blood pressure levels within the safety range. Doctors can prescribe medicines which can be safely used during pregnancy.

Pre-eclampsia

Sometimes hypertension in pregnancy is part of a different syndrome which used to be called Toxemia, but is now generally referred to as pre-eclampsia. Pre-eclampsia is a combination of symptoms with a wide range of expression. Often it is a very mild condition; other times it can be life-threatening. One of the primary purposes of prenatal care is to identify the woman with pre-eclampsia so she can receive treatment before she becomes dangerously ill.

Symptoms Of Preeclampsia

There are three symptoms historically used to identify the preeclampsia:

• A rising blood pressure
• Edema, meaning swelling from excess fluid
• Proteinuria, when a protein called albumin is found in the urine

Of course, we know most women experience some degree of swelling during pregnancy. If the swelling is only in the feet or ankles, and if it is gone in the morning after a night’s sleep, it is probably normal edema. Some women will also occasionally have a trace of protein in their urine, and many will have a slight rise in blood pressure in the last month of pregnancy. This makes it harder to tell if they are experiencing the onset of mild preeclampsia, so a doctor or midwife may schedule extra prenatal visits to monitor conditions more closely. She will probably order a blood test to look for changes which are often seen in preeclampsia, such as a rise or fall in hematocrit and a change in liver function.

Mild preeclampsia probably only needs to be watched. A woman will usually reach full term with no harm to her or her baby. But if the condition changes, or if it starts to affect the health of mother or baby, intervention is needed. The cure for preeclampsia is to deliver the baby, even if this means the baby is born prematurely. If the cervix is ripe, labor will be induced. If the cervix is unripe or the baby is very premature, the safest choice may be to deliver by cesarean section. This decision is best made in consultation with a perinatologist. The doctors will compare the benefit of waiting for greater fetal maturity against the risk that the preeclampsia may worsen to a dangerous state of severe preeclampsia or eclampsia.

Severe Preeclampsia or Eclampsia

On average, five to ten percent of pregnant women have some signs of pre-eclampsia. About five percent of the women with mild preeclampsia may develop severe preeclampsia. About five percent of the women with severe preeclampsia may continue to progress all the way to eclampsia. As you can see, severe preeclampsia is uncommon, and eclampsia itself is rare. But eclampsia is such an extremely dangerous condition for both the mother and the baby that every possible effort to be made to prevent preeclampsia from developing into eclampsia.

Eclampsia is a type of convulsion. It is thought to be caused by cerebral irritation, probably as result of the severely disturbed metabolic condition. Women with eclampsia go into extreme convulsions. They may stop breathing. The placenta may abrupt. The baby may die, and—in severe cases—the mother may die too. Fortunately, women in developed counties have access to medical care so that preeclampsia is successfully treated and eclampsia is prevented! Eclamptic convulsions are now, fortunately, extremely rare.