•  Complications Home
•  Glossary
•  Specific Complications
•  Bedrest Survival Guide
•  Success Stories
•  Suggested Books
•  NICU Support
•  Pregnancy After Loss Support
•  Pregnancy Channel

Bookmark and Share

Select a Week

StorkNet's Week By Week Guide to Pregnancy

Baby Namer

Enter a name
or words that
appear in its

Pregnancy Complications

Hypertensive Disorders ~ PIH, Preeclampsia, Eclampsia, HELLP Syndrome

Chemical Imbalance Precedes
Pregnancy-induced Hypertension

Pregnancy induced hypertension (PIH), commonly known as preeclampsia, can become a life-threatening condition. If a woman's blood pressure can't be brought under control, the baby must be delivered, or the woman may lapse into seizures and possible coma or death.

While no one has yet to figure out why some women develop PIH, researchers from the National Institute of Child Health and Human Development believe that part of the problem might be an imbalance between two blood chemicals occurring early in the pregnancy.

Prostacyclin, PG12, and thromboxan, TxA2, work in tandem as one piece of the complex system that maintains blood pressure. PG12 makes your blood vessels dilate, lowering blood pressure, and TxA2 constricts vessels, raising blood pressure.

The balance between PG12 and TxA2 is abnormal for months before any actual rise in blood pressure. Previous studies have focused on lowering TxA2, the chemical that causes a rise in blood pressure. However, testing with aspirin, a compound that lowers blood levels of TxA2, has proven ineffective. Researchers now think it's a low level of PG12, not a high level of TxA2 that may be the problem.

Researchers compared 134 women who developed preeclampsia against a control group of 139 pregnant women with normal blood pressure. All were tested for PG12 and TxA2 between 13 and 21 weeks gestation. They were all tested again between weeks 26 and 29, and a last time at 36 weeks.

All the women who developed preeclampsia had lower PG12 levels than the control group; and their levels were low from the first test, long before they developed preeclampsia. This upset the normal ratio between the two chemicals, and a rise in TxA2 found during the later tests worsened this imbalance.

Though they now know that the chemical imbalance precedes the development of preeclampsia, the results were not strong enough to predict who would develop PIH.

More study is required to ascertain if early treatment of low PG12 can head off preeclampsia. Previous research studies have shown that treating low PG12 is effective in treating pulmonary hypertension (high blood pressure involving the lungs). However, the participants in these studies were not pregnant women, so it remains to be seen if the mechanisms of high blood pressure are the same in PIH as they are in pulmonary hypertension.

If you like this article, we'd be honored if you shared it using the button below.
Bookmark and Share


Copyright © 1996-2016 StorkNet. All rights reserved.
Please read our disclaimer and privacy policy.
Your feedback is always welcome. Link to Us!

StorkNet Family of Websites:
StorkNet's Blog | Pregnancy Week By Week | Exploring Womanhood | Books for Families | EriChad Grief Support