The simplest method to find out the sex of the baby is using the European tables. Top (horizontal) are blood groups, which belong to the father. The left (vertical), respectively, blood group related to the mother. You need to compare two values to know the sex of the unborn child.
One of the varieties of previous practice is determining whether you have a boy or a girl using the RH factor. This method is less accurate, but is the place to be, especially as confirmation. To know group and RH factor, you can in the hospital or in the donor centers. The principle of this table is the same as the previous.
Perhaps the most difficult to use is a Japanese table to determine the sex of the child. You will need to use the month of birth of the mother and father, as well as the month in which it was carried out the conception. First map the data in the first table to obtain the desired number. Substitute it in the horizontal top row in the second table, and went down to the month name. The number of asterisks in the column is the probability that you have a baby on this floor.
To find out the baby's gender, you can also use ancient Chinese table. It all depends on the mother's age and month when you were conceived a child. Map the vertical and horizontal rows to get the result.