(NaturalNews) Most women do not know how much weight they are supposed to gain during pregnancy, according to a study published in the Australian and New Zealand Journal of Obstetrics and Gynaecology.
"Pregnancy is an important time that influences being overweight in both mothers and their babies," said researcher Susie de Jersey of the Queensland University of Technology in Australia. She is also senior dietician at the Royal Brisbane and Women's Hospital.
"Gaining too much or not enough weight, eating a poor diet and being physically inactive can affect the health of both mothers and their babies well into the future."
De Jersey found that two-thirds of Australian women did not gain an appropriate amount of weight during pregnancy. Perhaps surprisingly, just as many women under-ate as overate: one-third put on too many pounds, while another third either gained insufficient weight or actually lost weight between the time of conception and labor.
Pre-existing obesity was a major risk factor for gaining too much weight. Half of the women who were overweight at the time of conception gained too much weight over the course of their pregnancies.
"There are a lot of psychosocial factors in play - many of these women may have more negative experiences from trying to control their weight in the past," de Jersey said.
Pregnant women poorly informed
A major cause of the inappropriate weight gain might be the fact that so many of the women interviewed were poorly informed about prenatal nutrition.
"The majority of the women in the study knew healthy eating was important, but very few could identify how much they should be eating from different food groups, particularly fruits and vegetables," de Jersey said.
"Most women said they also didn't know the recommended amount of weight they should gain during pregnancy and reported very limited advice about healthy weight gain."
The amount of weight that a woman should gain during pregnancy depends on her body mass index (BMI) prior to conception. The higher the BMI, the less weight she should gain. For example, a woman with a healthy BMI (between 18.5 and 24.9) should gain 11.5-16 kg (25-35 lbs.) during pregnancy, while a woman with a BMI below 18.5 should gain as many as 40 lbs. and a woman with a BMI above 30 should gain no more than 20 lbs.
The women in the study were also poorly informed about exercise during pregnancy, with fewer than 50 percent of them considering it very important. This may come from the still-widespread but now discredited idea that exercise is not safe for pregnant women.
The best way to promote healthier weight gain among pregnant women is individualized counseling, de Jersey said, with special attention given to women who have struggled with their weight in the past.
"Giving intensive support to mothers at this time may help to instill healthy habits that can have flow-on effects for not only the mother and baby during pregnancy, but also to help lower the child obesity rate," she said.