There are a number of natural causes that can lead to the birth of twins. For example, the presence in the pedigree of the spouses of twins can increase your chances to give birth to twins. These chances are higher if the twins were not identical.
Another factor that could affect the birth of twins may be age. Studies show that the older female (over 35 years), the higher her chances to give birth to twins. This is because before menopause, ovarian woman begins to produce more than one egg per month. In addition, in this period there is a surge in the production of estrogen.
Some studies show that folic acid supplementation can dramatically increase the chances (40% or more) to get pregnant with twins. However, this method is not reliable. There are studies which do not support the use of folic acid. In any case, the admission of this substance helps prevent neural tube defects. Take it even if you do not plan on twins.
Increase the intake of dairy products and sweet potatoes (yams). It is believed that these foods can increase the chances of getting pregnant with twins, but scientific proof of this. To increase your chances of also can diet your partner. Ask him to eat more oysters. This product is very rich in zinc, which increases sperm production, which in turn makes more likely is the fertilization of two eggs. Good sources of zinc are also green leafy vegetables, bread, cereals and whole grains.
If you are taking fertility drugs or use IVF, your chances of having twins also increase. Similar effects on the body stimulate the ovaries to maintain two or more ovarian follicles every month. The result is more eggs, which increases the chance of multiple births.
Weight women can also affect the birth of twins. Numerous studies show that BMI (body mass index) above 30, increases the chances of twins. However, you must remember that procreation is considered the optimal BMI of 20 to 25. Higher rates are unsafe.
To increase the chance of getting pregnant with twins is possible and mathematically. If you have a large family and you are planning to bear on, your chances increase. In addition, the fact that you have already given birth, by itself, increases your chances of twins.