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.
Some people are prone to nighttime cramps, but can be worsened by certain activities, footwear, dehydration, mineral deficiencies, diuretics and other medication. For example, Aricept (donepezil) is known to cause leg cramps as well as nightmares. I look for a pattern.