In particular, a major vein called the inferior vena cava, which is on the right side of your body, is working very hard. Its job is to carry blood from your lower body back up towards your heart, but all the extra blood, not to mention pressure being put on your pelvic veins by your growing uterus, tends to make the inferior vena cava less efficient.
The result is that your blood pools, and water is then forced down through capillaries (tiny blood vessels) towards your lower legs, ankles and feet. To add to all this, pregnancy hormones upset all sorts of normal balances within your body, including levels of sodium and potassium – and this leads to your body retaining more fluid, rather than absorbing and expelling it.
Water retention normally occurs from the feet up (you might notice your shoes start to feel tight) with ankles and lower legs also commonly affected. Towards the latter stages of pregnancy, your hands might also swell and feel a bit podgy. All these symptoms will often worsen as the day goes on; your feet might look quite normal when you wake, and like plucked chickens by bed time!
Although water retention is unpleasant, with affected areas feeling heavy, or wobbly and tender, the good news is everything should go back to normal shortly after your baby arrives. During the first few days after giving birth, it might feel worse than ever, but then suddenly, you'll find yourself needing a wee constantly and sweating profusely. As attractive as that sounds, it's just your body's natural way of expelling all the excess fluid.
Before reading about ways to relieve the symptoms of water retention, it's very important to distinguish between oedema, which is common and poses no risk, and pre-eclampsia, which is a serious condition requiring urgent treatment. If swelling comes on suddenly or severely in your hands, feet and/or face, seek medical attention as soon as possible.
What can I do?
One of the most effective ways to help alleviate water retention is to drink more water. As odd as that sounds, your body is hanging on to the fluid because it feels it doesn't have enough! So don't let yourself become dehydrated. While you shouldn't cut out salt completely when pregnant, you should avoid very salty meals and snacks, and junk food which is likely to be laden with hidden sodium.
Resting your legs and putting your feet up takes the strain off your lower body. If you work all day in a sitting position, get a foot stool to elevate your feet a little, and be sure to have a walk around every now and then to get your circulation going. Regular gentle exercise in your free time, such as walking or swimming, will help too.
Maternity support tights, which you should be able to buy in major pharmacies, should help somewhat, and you should also sleep on your left hand side, to reduce the amount of pressure on that all important inferior vena cava vein.
The skin around swollen ankles and feet can feel taught and tender, so a cooling and moisturising leg gel might be just the ticket at the end of the day. Or, if it's not painful for you, ask your partner or a friend to gently massage your feet, ankles and lower legs, using upward strokes towards the knees – this can help to shift some of the fluid and reduce the tension down there.
While you shouldn't take diuretics when you're expecting (oh, how much easier pregnancy would be if we could just medicate ourselves!), there is a natural remedy you might like to try.
You may have already heard about those new mums who put cabbage leaves in their bras to alleviate the soreness of their engorged boobs? Well, some women swear by the same method for swollen ankles.
Put a fresh green cabbage in the fridge for a couple of hours until cool. Strip off some big leaves, wrap around your ankles until they're covered, and then use bandages to hold them in place (if you have a big bump, you might need help with this!).
Now put your feet up for as long as you can. The leaves actually help to draw water out through the skin.
If you don't have a cabbage to hand (stock up!), soaking your feet in cool water might help to soothe away some of the aches and pains. Sip a cool drink while you do so, or perhaps a cup of dandelion tea (which is thought to be a natural remedy for water retention, due to its potassium content).
If you notice that your hands and fingers are starting to swell (again, this is likely to be worse as they day goes on, and will also worsen as your pregnancy progresses), you should take your rings off. If you leave them on and your fingers continue to increase in size, your rings might get stuck and it could be very uncomfortable for you indeed.
If you are particularly uncomfortable with your oedema, ask your midwife for more advice.
What else could it be?
If you have suddenly experienced severe swelling in your face, hands and/or feet, and particularly if you have other symptoms including headaches, blurred vision, vomiting or pain in your abdomen, seek medical advice immediately because you might have pre-eclampsia.