Researchers at St Thomas' Hospital in London say four out of ten women need to supplement their diets with vitamins.
"In an ideal world," sys Dr Andrew Shennan, of St Thomas' Hospital, "a healthy, balanced diet should provide pregnant women and their developing babies with all the nutrients required for optimum health. But many mums-to-be who take care to eat healthily frequently fight sickness, nausea, heartburn and exhaustion, which reduces their appetite."
"Women also tend to have an unhealthy diet prior to pregnancy," he said. "It is clear that many women need to top up their essential nutrients."
"Conditions like as pre-eclampsia are extremely hard to identify. And micronutrient supplementation may be a way of reducing its impact, possibly in all women," he added.
What you need to take: Vitamin C and E supplements, which will reduce the risk of pre-eclampsia, a potentially life-threatening condition that affects upto 10 percent of pregnancies.