The supplements notably failed to reduce the risk of preeclampsia, a potentially fatal form of hypertension in pregnancy. The findings are in contrast to suggestions in some previous small studies that the vitamins could reduce the risk of preeclampsia. Those studies were not confirmed in subsequent larger studies.
The NIH study, the largest to date and one in which treatment was started earliest in pregnancy, also showed no reduction in pregnancy-associated hypertension and its complications.
"The study results effectively rule out vitamin C and E supplements as a means to prevent the hypertensive disorders seen in pregnancy," said Alan E. Guttmacher, M.D., acting director of the Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), one of the NIH Institutes that provided funding for the study.
Major funding for the study was also provided by the National Heart, Lung, and Blood Institute, with additional funding provided by the National Center for Research Resources' Clinical and Translational Science Awards program, both of the NIH.
The findings appear in the April 8 issue of the New England Journal of Medicine.
The study was conducted at 16 sites within the NICHD's Maternal–Fetal Medicine Units (MFMU) Network. The article's first author was James M. Roberts, M.D., of the Departments of Obstetrics and Gynecology, University of Pittsburgh.
The study included only women giving birth for the first time, a group at higher risk for developing hypertensive disorders of pregnancy. In general, the women were healthy and did not have high blood pressure, protein in the urine (an indication of stress on the kidneys), or gestational diabetes (a form of diabetes that emerges in pregnancy). The researchers enrolled over 10,000 women, starting in the ninth to 16th weeks of pregnancy, and followed them to delivery. The women also received daily supplements of vitamins C and E or a placebo.
"In the United States, obstetricians generally recommend that pregnant women take a multivitamin formulated for pregnancy, especially if they aren't eating a well-balanced diet," said study co-author Catherine Y. Spong, M.D., chief of NICHD's Pregnancy & Perinatology Branch and program scientist for the MFMU Network. "In our study, participants took supplements containing higher doses of vitamins C and E—about 10 times the amount in typical prenatal vitamins—in addition to any pregnancy vitamins they may have been taking."
Based on earlier studies, researchers theorized that vitamins C and E might reduce the chances of preeclampsia by preventing damage from molecules known as free radicals— byproducts of the body's use of oxygen. The theory held that free radicals could prevent the placenta from developing properly and interfere with blood flow from the mother to the baby. Although the current findings neither support nor contradict the idea that free radical damage can lead to preeclampsia, Dr. Spong said, they do show that treatment with vitamins C and E will not prevent the condition.
The combined rates of pregnancy-associated hypertension, seizure, protein in the urine, preeclampsia, blood or liver abnormalities, loss of the pregnancy, an underweight baby and preterm delivery did not differ statistically between the two groups. The combined rate of complications was 6.1 percent among those taking the study vitamins and 5.7 percent of those taking the placebo.
Moreover, the study did not detect any statistical difference in preeclampsia between the two groups: 7.2 percent among women taking vitamins versus 6.7 percent among those who took the placebo.
Dr. Spong added that the results are welcome for the clarity they provide.
"These results are very useful," Dr. Spong said. "In this case, it shows us that what originally appeared to be a promising treatment did not actually offer any benefit clinically."
Robert Bock | EurekAlert!
The personality factor: How to foster the sharing of research data
06.09.2017 | ZBW – Leibniz-Informationszentrum Wirtschaft
Europe’s Demographic Future. Where the Regions Are Heading after a Decade of Crises
10.08.2017 | Berlin-Institut für Bevölkerung und Entwicklung
Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a...
Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!
When x-rays shine onto solid materials or large molecules, an electron is pushed away from its original place near the nucleus of the atom, leaving a hole...
For the first time, physicists have successfully imaged spiral magnetic ordering in a multiferroic material. These materials are considered highly promising candidates for future data storage media. The researchers were able to prove their findings using unique quantum sensors that were developed at Basel University and that can analyze electromagnetic fields on the nanometer scale. The results – obtained by scientists from the University of Basel’s Department of Physics, the Swiss Nanoscience Institute, the University of Montpellier and several laboratories from University Paris-Saclay – were recently published in the journal Nature.
Multiferroics are materials that simultaneously react to electric and magnetic fields. These two properties are rarely found together, and their combined...
MBM ScienceBridge GmbH successfully negotiated a license agreement between University Medical Center Göttingen (UMG) and the biotech company Tissue Systems Holding GmbH about commercial use of a multi-well tissue plate for automated and reliable tissue engineering & drug testing.
MBM ScienceBridge GmbH successfully negotiated a license agreement between University Medical Center Göttingen (UMG) and the biotech company Tissue Systems...
Pathogenic bacteria are becoming resistant to common antibiotics to an ever increasing degree. One of the most difficult germs is Pseudomonas aeruginosa, a...
19.09.2017 | Event News
12.09.2017 | Event News
06.09.2017 | Event News
20.09.2017 | Life Sciences
20.09.2017 | Power and Electrical Engineering
20.09.2017 | Physics and Astronomy