|Physical Development of Twins|
|In comparison with single-born twins have five times more risks of premature birth (up to 37 weeks), 9,5 times more often risk of too low-birth-weight (less then 1500 gr.) and 8,5 times more risk of low-birth-weight (less than 2500 gr.) Studies have shown that all these defects of intrauterine development disappear in childhood.|
The difference between twins sizes can be explained by some factors such as placenta location, position in uterus, fetus position in third trimester of pregnancy. The lesser twin usually have high risk of death in uterus or soon after the birth. Examinations of twins with difference in weight up to 25 % have shown that the differences in weight, height, and head size disappear to 9,5 years. Besides they don't differ from each other in mentality and in studies. But it has been noticed that the twin with higher birth-weight has better developed subtle motility, coordination of movements and visual-motor coordination.
In the absence of height gap death-rate soon after the birth of twins doesn't exceed the rate of single-born. There is information about distinct height gap of twins in the first year but the difference disappears completely to 8 years age.
On average the boys twins are born 0,6 week later then girls. The weight and height of boys are higher then girls but the height gap is also more often thing (17% in boys and 10% in girls.)
The physical development difference is widespread among the twins. But its frequency and degree of manifestation are decreasing constantly. Even if the difference between twins remains it doesn't overstep the limits of norm.