Risk factors
Some women have a greater risk of developing hypertension during pregnancy. These are:

Women with chronic hypertension (high blood pressure before becoming pregnant). Women who developed high blood pressure or preeclampsia during a previous pregnancy, especially if these conditions occurred early in the pregnancy. Women who are obese prior to pregnancy. Pregnant women under the age of 20 or over the age of 40. Women who are pregnant with more than one baby. Women with diabetes, kidney disease, rheumatoid arthritis, lupus, or scleroderma. Diagnosis
There is no single test to predict or diagnose preeclampsia. Key signs are increased blood pressure and protein in the urine (proteinuria). Other symptoms that seem to occur with preeclampsia include persistent headaches, blurred vision or sensitivity to light, and abdominal pain.All of these sensations can be caused by other disorders; they can also occur in healthy pregnancies. Regular visits are scheduled to track blood pressure and level of protein in urine, to order and analyze blood tests that detect signs of preeclampsia, and to monitor fetal development more closely. Classification
A classification of hypertensive disorders of pregnancy uses 4 categories as recommended by the U.S. National High Blood Pressure Education Program Working Group on High Blood Pressure in Pregnancy:
Chronic hypertension;
Preeclampsia-eclampsia;
Preeclampsia superimposed on chronic hypertension;
Gestational hypertension (transient hypertension of pregnancy or chronic hypertension identified in the latter half of pregnancy).This terminology is preferred over the older but widely used term pregnancy-induced hypertension (PIH) because it is more precise.
Certain medications may not be ideal for blood pressure control during pregnancy such as angiotensin-converting enzyme (ACE) inhibitors and angiotensin II (AII) receptor antagonists. Controlling weight gain during pregnancy can help reduce the risk of hypertension during pregnancy.There is limited evidence to suggest that calcium supplementation may reduce the risk of pre-eclampsia or stillbirth but it is unclear if it has other benefits. Management
The only way to definitively treat a hypertensive disease of pregnancy (i.e. preeclampsia/eclampsia, gestational hypertension, etc. ) is to deliver the fetus. This prevents further development of complications related to the disorder in both the mother and the fetus. Therefore, the first line approach to management of these conditions is to consider induction of preterm labor. The exact timing of when to induce labor is dependent on the severity of symptoms related to the hypertensive disease, as well as the medical condition of both the mother and the fetus. Generally, in mothers with preeclampsia, labor is induced once the gestational age is >37 weeks. In patients with preeclampsia with severe features or eclampsia, labor is induced once the gestational age is >34 weeks. In patients with gestational hypertension and no other signs of severe disease, labor is generally induced at term.In cases where the fetus has not yet reached a safe gestational age to be delivered, management is focused on managing symptoms to give the fetus more time to mature.