Women who "eat for two" when they are pregnant are increasing the chances of problems giving birth and lifelong health issues for their children, according to a New Zealand-led international study. The study found that 74 percent of women pregnant for the first time, gained excessive amounts of weight during pregnancy, quadrupling the chance of having an excessively large child at birth and increasing the number of cesarean deliveries in labor. "Big babies become big children and big adults later on," said Professor Lesley McCowan, of the University of Auckland, who led the study. "Babies born large are at risk of traumatic birth, and cesarean delivery increases the chance of complications for the mother," said McCowan in a statement. "These adverse outcomes can be modified by achieving optimal weight gain in pregnancy. This should be an important focus of ante-natal care." Weight gain during pregnancy was also an important cause of obesity in women. "Most women who gain too much weight are not able to lose that weight after pregnancy and it puts those women on a trajectory to becoming obese," she said. "Excessive weight gain during pregnancy will not only exacerbate existing obesity, but will contribute to later obesity in women who start pregnancy with a normal body mass index but have excessive weight gain in pregnancy," she said. "Nutritional interventions can limit weight gain and improve pregnancy outcomes by reducing the chance of a big baby and also reduce the chance of the mother developing gestational diabetes and pre-eclampsia, conditions which can have lifelong consequences for mother and baby." The study, covering 1,950 women in New Zealand, Australian and Ireland, found 7.2 percent achieved the recommended pregnancy weight gain, while 8.6 percent gained less weight than the recommended amount and 74.3 percent gained an excessive amount.