Pregnancy induced hypertension, or PIH, is a disorder that causes high blood pressure in pregnancy. It is an older term that is no longer used very often as a medical diagnosis. If you are pregnant and have high blood pressure, your doctor will want to find out what kind of high blood pressure you have in order to treat it.
Types of High Blood Pressure in Pregnancy
If you were diagnosed with pregnancy induced hypertension during an earlier pregnancy, you may need to learn new terminology. What used to be called PIH is usually called preeclampsia or gestational hypertension now. Doctors know more about the types and causes of high blood pressure in pregnant women than ever before, and will be better able to pinpoint exactly what type of high blood pressure you have.
The hypertensive disorders of pregnancy are broken down into four categories:
- Preeclampsia/Eclampsia: Preeclampsia can be mild or can be a severe, life-threatening condition. Symptoms of preeclampsia include high blood pressure, protein in the urine, and a number of other symptoms. Healthy women with no risk factors can develop preeclampsia, which is why your physician will check your blood pressure and your urine at each prenatal appointment.
- Chronic Hypertension: If you had high blood pressure before your pregnancy, you may have been diagnosed with chronic hypertension. Your doctor will want to follow you closely to make sure that you don't develop signs of preeclampsia and to make sure that your baby is growing well. Most women with chronic hypertension have normal pregnancies with healthy babies as long as their blood pressure stays under control.
- Chronic Hypertension With Preeclampsia: If you had chronic hypertension before your pregnancy, you have a higher risk of developing preeclampsia as well. It can be hard to diagnose preeclampsia in women who have chronic high blood pressure, so be sure to make your prenatal appointments on time and to follow your doctor or midwife's recommendations.
- Gestational Hypertension: Sometimes, a mom with no history of high blood pressure develops hypertension in the last half of her pregnancy. If she doesn't have any other symptoms of preeclampsia, she is said to have gestational hypertension. This type of high blood pressure usually goes away after delivery, but may reappear as chronic hypertension later in life.
High blood pressure that's caused by pregnancy usually goes away after delivery of the baby, as the mom's body returns to its prepregnancy state. If the baby isn't growing well or if the mom is developing signs of moderate to severe preeclampsia, the doctor may want to intervene.
Many medications can safely be used to manage blood pressure during pregnancy. Your doctor may need to change your high blood pressure medicine or dose as your body changes during your pregnancy. Be sure to tell your doctor if you plan to breastfeed so that you can choose treatment options that are safe for your baby.
If you have severe high blood pressure, your doctor may order hospital bed rest. Your blood pressure and your baby's health will be monitored closely while you are hospitalized.
If you start to develop signs of severe preeclampsia, then delivery of the baby may be the best choice. Preeclampsia can lead to complications including eclampsia and HELLP syndrome, both of which are life-threatening medical emergencies for both mom and baby. If your baby will be premature, doctors will weigh the complications from prematurity against the complications of preeclampsia, and will decide with you whether it is better to continue the pregnancy or deliver the baby.
World Health Organization. "WHO Recomendations for Prevention and Treatment of Pre-eclampsia and Eclampsia." (2011) Accessed April 10, 2012 from http://www.preeclampsia.org/images/pdf/2011c-who_pe_final.pdf
Lindheimer, M., Taler, S., Cunningham, G. "ASH Position Article: Hypertension in Pregnancy." Journal of the Americn Society of Hypertension 2008: 2, 484-494.