The blood pressure drops during second trimester of Pregnancy in most women and then it returns to the normal level by the end of third trimester. However in certain women (about 10%) blood pressure increases during second and third trimester of pregnancy. This condition is termed as pregnancy-induced hypertension.
High blood pressure can remain mild during pregnancy or it can be severely high and needs close monitoring and regular treatment.
- Mild High Blood Pressure: It is not that dangerous though needs close monitoring as mild high blood pressure may lead to serious condition like preeclampsia. After delivery, the blood pressure becomes normalwithin twelve weeks and is termed as ‘Transient Hypertension of Pregnancy’
- Severe High Blood Pressure:It limits the blood oxygen supply to the fetus, which cause in poor fetal growth, early separation of the placenta from the wall of the uterus (placenta abruption) and even might lead to stillbirth. So a regular treatment is needed and medication is applied to keep the diastolic blood pressure within 100mm of Hg.
- Chronic (Long Term) High Blood Pressure : This high blood pressure is present even from before pregnancy and is a lifelong condition though treatable. But it might risky as it develops a chance for Preeclampsia in one fourth of the cases.
- Preeclampsia:Preeclampsia is the new onset of high blood pressure in the pregnant mother with blood pressure higher than 140/90 mm Hg(millimeters of mercury). In this cases protein level is also higher than normal in urine sample.
If preeclampsia is severe it is a life-threatening pregnancy problem.Preeclampsia starts with the placenta that does not grow normal blood vessel network deep into the uterine wall, which results in poor blood circulation through the placenta. It also causes mild to severe high blood pressure in mother. The condition leads to reduced blood supply in fetus and sometimes also cause problem with the brain, liver and kidney function of the pregnant mother. Woman with severe Preeclampsia might develop life threatening seizures, a condition named eclampsia.
Preeclampsia only occurs during or after the pregnancy. 5 % of the pregnant women are affected by this and it is most common in first time pregnancies. Some preeclampsia lasts up to two weeks after delivery and then become normal.
The good side of Preeclampsia is it probably does not lead to future high blood pressure. Instead experts opine that the women having preeclampsia may have lower risk of chronic high blood pressure.
In some cases both high blood pressure and preeclampsia might take place during pregnancy. It can develop gradually or might occur suddenly and range from mild to severe high blood pressure. If the patient develops high blood pressure during pregnancy there is no way to know whether it is a sign of preeclampsia or not. So the women with high blood pressure during pregnancy are closely monitored for the signs of preeclampsia.