Carbon monoxide key to preeclampsia treatment

Washington: A study has revealed that controlled Carbon monoxide (CO) doses could help prevent or treat early preeclampsia (PE).

Research has found that, compared with that of healthy pregnant women, the breath of women who are diagnosed with PE contains significantly lower levels of CO, one of the combustible elements in cigarettes and which is not present in smokeless tobacco.

Although toxic at high levels, low levels of CO are produced naturally by the body and have positive effects.

The study, led by Graeme Smith of Queen's University, Canada, found that exposing the animals to inhalable CO increased blood flow and vascular growth in the developing placenta, created more, bigger, and stronger connections to the mother's uterus, a process that provides more oxygen and nutrients to the foetus.

And, since PE is a multifaceted disorder that begins with abnormal placental development before progressing to maternal disease, the results also suggest the possibility of preventing or treating early PE in humans with controlled CO dosages.

Beginning on gestation day, pregnant female mice were placed in a sealed chamber with as much food and water as they wanted and exposed to CO, either chronically or acutely twice during gestation, at levels that allowed mouse CO blood levels to reach levels comparable to a one-pack-per-day female smoker.

Maternal weight, live foetuses, foetal resorptions, and implantation sites were compared to control mice. Doppler analysis was performed on day 5 (baseline), 10 (when placental structure has formed and blood begins to cross the placenta to the foetus), and 14 (when blood velocity is well-established and foetal vasculature begins).

Mice were then anesthetized and a cast was made of the entire uterus and blood vessels, then mounted and three-dimensionally imaged by micro-CT.

Compared to controls, CO exposure did lead to increased vessel diameter, a significant increase in the number of radial artery branches, and significantly higher maternal blood flow.