Scroll way down to the bottom of the Hot One Hundred top breeders and youll eventually find the United States, hovering just at replacement rate with 2.07 births per woman.
Most of the time, no apparent cause for night leg cramps can be identified. In general, night leg cramps are likely to be related to muscle fatigue and nerve problems. The risk of having night leg cramps increases with age. Pregnant women also have a higher likelihood of having night leg cramps. Several conditions, such as kidney failure and diabetic nerve damage, are known to cause night leg cramps. But if you have one of these, you're most likely aware of it and have symptoms other than night leg cramps.
In some cases, calf cramps at night may be caused by a fluid imbalance or a vitamin deficiency. Apart from these main speculative causes of calves cramps, there are many other causes cited as responsible for these cramps at night. Overused and strained calf muscle. You might have tried a new exercise or overdone some of the exercises that strain your calf muscles. Injury to Achilles Tendonitis tendon. Pain due to some injury to Achilles tendon which joins the calf muscles with the heel might also intensify your calf cramps at night.