Animal studies have found that the activity of Fallopian tubes, which carry eggs from her ovaries to her uterus, can be undermined by regular caffeine intake, thus negatively affecting her fertility, researchers from the University of Nevada School of Medicine reported in the British Journal of Pharmacology.

Professor Sean Ward said:

"Our experiments were conducted in mice, but this finding goes a long way towards explaining why drinking caffeinated drinks can reduce a woman's chance of becoming pregnant."

If a woman is to have a successful pregnancy, her microscopic eggs have to travel to her uterus (womb). Not much is known about how the eggs travel through the muscular Fallopian tubes. Experts presumed cilia - minute hair-like projections - in the lining of the tubes slowly push the egg, along with muscular contractions in the tube walls.

Ward and team found that specialized pacemaker cells, the ones involved in coordinating the tube contractions, became much less active when mice were given caffeine.

The authors wrote that the role of the tube contractions is much greater than that of the cilia in pushing the eggs along.

Professor Ward said:

"This provides an intriguing explanation as to why women with high caffeine consumption often take longer to conceive than women who do not consume caffeine."

Ward adds that this discovery about reduced fertility and caffeine consumption has benefits.

He said:

"As well as potentially helping women who are finding it difficult to get pregnant, a better understanding of the way Fallopian tubes work will help doctors treat pelvic inflammation and sexually-transmitted disease more successfully."

The authors believe their findings may also help better understand the causes of ectopic pregnancies.

"Inhibitory effect of caffeine on pacemaker activity in the oviduct is mediated by cAMP-regulated conductances"
R. E. Dixon, S. J. Hwang, F.C. Britton, K. M. Sanders and S. M. Ward.
British Journal of Pharmacology. 2011; DOI: 10.1111/j.1476-5381.2011.01266.x

Written by Christian Nordqvist