Preventing Preeclampsia in Women With Chronic Hypertension Lowers Death Risk: Study

Chronic hypertension did not significantly increase the risk of severe health problems during pregnancy for women who did not develop preeclampsia.

A new study suggests that healthcare providers should focus on identifying and preventing preeclampsia in pregnant women, as it has a greater impact on severe health complications than chronic hypertension alone.

Researchers from Kaiser Permanente published a study in the journal JAMA Network Open on January 28, highlighting how preeclampsia increases the risk of severe health issues for the mother, including death, by a factor of five. Researchers further noted that while chronic hypertension raises the likelihood of developing preeclampsia, the severity of the risk does not change based on whether she has chronic hypertension.

Preeclampsia is a complication experienced during pregnancy that is considered a type of severe hypertension, or high blood pressure. Symptoms include swelling of the hands and feet, severe headache, blurred vision and pain in the abdomen.

The condition can lead to serious complications for both the mother and infant, including seizures, stroke, kidney failure, preterm birth, and when not treated quickly, death.

For this study, Kaiser Permanente researchers in California, led by Dr. Erica P. Gunderson, analyzed the impact of different combinations of hypertension and preeclampsia during pregnancy and how that affected the rate of severe maternal morbidity (SMM), which includes both serious health side effects and death.

They analyzed data from 263,000 pregnant patients without preexisting heart, kidney or liver disease from 2009 to 2019. The data was taken from electronic health records from patients in a community-based healthcare system in Northern California.

The research team categorized the women into five groups: chronic hypertension with preeclampsia, chronic hypertension and no preeclampsia, no chronic hypertension with preeclampsia, gestational hypertension, which only occurs during pregnancy, and no chronic hypertension, no gestational hypertension and no preeclampsia.

Overall, preeclampsia developed in 32% of patients with chronic hypertension and 5% of patients who did not have chronic hypertension, according to the findings. However, the researchers determined that if preeclampsia in women with chronic hypertension could be prevented, their risks of SMM dropped to about the same as other expecting mothers.

The data indicates the risk of severe disease or side effects during pregnancy was five times greater for women who had preeclampsia. Women who had gestational high blood pressure also faced double the risk of severe disease or side effects.

The researchers noted that patients with chronic high blood pressure, who did not develop preeclampsia, had the same low risk of severe side effects as women without chronic hypertension, gestational hypertension or preeclampsia. They concluded the biggest health benefit came from preventing the development of preeclampsia, which increased the risks of heart, kidney and liver disease.

“The patients with chronic hypertension who did not develop preeclampsia had SMM rates that were nearly the same as the lowest-risk patients without chronic hypertension who did not develop preeclampsia or gestational hypertension,” the researchers wrote. “These findings provide evidence that prevention of preeclampsia among patients with uncomplicated chronic hypertension is paramount to mitigating maternal morbidity.”

Previous studies have found that chronic hypertension, which is a risk factor for preeclampsia, has doubled in recent years. In addition, other research has warned that U.S. hospitals are unprepared to treat preeclampsia, even though the condition is easily resolved when addressed quickly and doctors are trained properly.