Pregnant woman eating saladIf you're planning to have a baby, it’s an ideal time to think about your health and that of your partner. If you're overweight or underweight, it's a good idea to try to achieve a healthy weight before you stop using contraceptives. Research shows that diet can affect the health of the baby and can also influence a baby’s health into adulthood. If a growing baby is inadequately nourished in the womb, this increases the risk of heart disease, diabetes and high blood pressure in adulthood.