This nerve is pinched when you stand or walk so lying down with your hip flexed may help. The problem goes away after delivery. This is very common later in pregnancy and usually of no significance. If your hands are getting puffy do take your rings off before they become stuck. Your doctor or midwife will want to check your blood pressure and urine at the ante-natal clinic to make sure the ankle swelling is not associated with other problems.
Leg cramps affect one third of women in the later half of pregnancy.
For some women they can be quite severe, particularly at night. There is little one can do to help but try raising the foot of the bed by 20cm to elevate your legs at night. Just occasionally women develop a clot in the deep veins of the leg. If your ankle swelling is in one leg only and your calf muscles are hot and tender see your doctor for advice. Approximately half experience some vomiting symptoms.