It's the perfect excuse to get out and about. Research suggests getting enough vitamin D, produced by sunlight on the skin, can significantly reduce your risk of pre-eclampsia.
Researchers at the University of Pittsburgh found that women who are deficient in vitamin D during early pregnancy are five times more at risk of developing the condition.
Pre-eclampsia is potentially dangerous for both mother and child.
Vitamin D is found in a small number of foods like oily fish and eggs, fortified milk, butter, cereals and bread.
'However, the vitamin D made by one bout of sunlight exceeds more than tenfold the amount provided by a daily diet,' says GP Dr Sarah Brewer.
'As well as eating plenty of vitamin D-rich food, exposing your skin to short bursts of sunlight (10-15 minutes) is important.'
Action on Pre-Eclampsia: www.apec.org.uk