Study Highlights:

  • Obesity may potentially lead to preeclampsia, a form of dangerous high blood pressure that can occur during the second half of pregnancy.
  • As early as the first trimester of pregnancy, researchers found that obese women had higher blood pressure and changes in heart structure and function that may precede the onset of preeclampsia.

Embargoed until 3 p.m. Central Time/ 4 p.m. Eastern Time, Wednesday, August 1, 2018

SAN ANTONIO, TEXAS, August 1, 2018 — Even in young women, obesity may potentially lead to heart complications during and after pregnancy, according to preliminary research presented at the American Heart Association’s Basic Cardiovascular Sciences Scientific Sessions, a premier global exchange of the latest advances in basic cardiovascular science.  

Obesity is a risk factor for preeclampsia, a type of dangerous high blood pressure that can occur during the second half of pregnancy and leaves women more prone to high blood pressure and heart disease later in life.  

The term “obesity” is used to describe the health condition of anyone significantly above his or her ideal healthy weight. Nearly 70 percent of American adults are either overweight or obese. Being obese puts you at a higher risk for health problems such as heart disease, stroke, high blood pressure, diabetes and more.

“The cardiovascular system of women undergoes profound changes during pregnancy, which return to pre-pregnancy levels three to six months after delivery. The main goal of this ongoing study is to follow women through pregnancy to detect whether there are differences in how an obese woman’s cardiovascular system changes during pregnancy that might explain their predisposition to preeclampsia and other cardiovascular complications,” said Katherine Shreyder, M.D., Ph.D., a medical resident in the department of internal medicine at Texas Tech University Health Sciences Center at Permian Basin in Odessa, Texas.

The researchers assessed heart and chemical changes in 11 obese (average body mass index 33.6, average age 29.6 years) and 13 normal or overweight (average body mass index 25.5, average age 26.3 years) women throughout their first pregnancies. A 5’4” woman with a body mass index of 33.6 would weigh 196 pounds; a woman of the same height with a body mass index of 25.5 would weigh 149 pounds.

The majority (85 percent) of the women were Hispanic. Women were not enrolled in the study if they had pre-existing heart abnormalities or other conditions that increase the risk of pregnancy complications, including a history of high blood pressure, diabetes, or carrying twins or triplets.

During the first trimester of pregnancy, the researchers found that obese women had (in comparison with the normal or overweight women):

  • a thicker left ventricle (the heart’s main pumping chamber), which can make it more difficult to pump efficiently (average 122.6 grams vs. 97.4 grams);
  • lower E/A ratio, a measure of how well the heart’s pumping chamber relaxes and fills with blood between contractions (average 1.5 vs. 1.83);
  • lower ejection fraction, indicating that the left ventricle is weaker during contraction (average 71 percent vs. 73.7 percent);
  • higher systolic (top number) blood pressure (average 125 mm Hg vs. 109 mm Hg); and
  • higher diastolic (lower number) blood pressure (average 79.7 mm Hg vs. 68.8 mm Hg).

“It seems that the obese patients will be more likely to deteriorate during pregnancy, because we started to observe higher blood pressure (although still in the normal range), an increase in left ventricular mass, and diminished pumping strength and relaxation,” Shreyder said.

As researchers continue follow the women throughout their pregnancy and for six months postpartum, they will also analyze whether levels of certain biomarkers of inflammation or obesity are related to changes in echocardiograms or the development of preeclampsia.

“Echocardiography might turn out to be a useful screening tool in obese pregnant women if further research establishes a definite connection between changes seen on echocardiography early in pregnancy and the risk of preeclampsia,” Shreyder said.

Preeclampsia, also sometimes known as toxemia of pregnancy, occurs after the 20th week of gestation and is characterized by high blood pressure and elevated levels of protein in the urine. It is more common in first pregnancies. Preeclampsia can harm the placenta, cause organ damage in the woman, and result in stillbirth or other fetal complications.

Once the diagnosis of preeclampsia is established, subsequent management will depend on the results of maternal and fetal evaluation, gestational age, presence of labor or rupture of membranes, vaginal bleeding and the wishes of the woman.

Regular prenatal care, including blood pressure measurements and urine tests, is needed to detect the onset of preeclampsia, which usually has no symptoms.

The study is limited by the small number of participants and the lack of pre-pregnancy data on the measures being tracked. The researchers plan to expand the study to a larger and more ethnically diverse group of pregnant women.

This study is part of the extensive ongoing research dedicated to prevention of obesity complications in pregnancy conducted in the Texas Tech University Health Sciences Center at the Permian Basin Campus (PI Natalia Schlabritz-Lutsevich, M.D., Ph.D.).

Co-authors are: Maira Carrillo, Ph.D.; James Maher, M.D.; and Natalia Schlabritz-Lutsevich, M.D., Ph.D. Author disclosures are on the abstract.

The Dean of the Texas Tech Sciences Center in Permian Basin, Texas Tech Advisory Council, Department of Obstetrics and Gynecology, Department of Internal medicine and Texas Tech Clinical Research Institute funded the research.

Additional Resources:

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