It appears that caffeine reduces muscle activity in the Fallopian tubes. This is the vital pathway that carries the egg from ovary to uterus where it can be fertilized and implant to develop.
“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,” says Professor Sean Ward from the University of Nevada School of Medicine. His study is published in the British Journal of Pharmacology.
Admittedly, scientists know little about how an egg actually travels down the Fallopian tubes, but they do know it’s a vital journey. It has been assumed that the tiny hair-like projections called cilia which line the tubes gently moved the eggs along in the right direction. The cilia are moved by tiny, coordinated muscle contractions.
When the mice were studied the researchers discovered that caffeine stops the waft-like motion of the cilia. The eggs don’t move down the tubes. “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,” says Ward.
This could also help explain ectopic pregnancy in some cases, a condition where the embryo starts to develop while attached to the Fallopian tube wall.
Source: British Journal of Pharmacology, MedicalNewsToday