Make Sure You Stay Hydrated During Pregnancy

Hello summer! Keep well hydrated as the weather gets warmer

The winter months are over, the days are longer and as the temperature gets warmer, let’s see how water can look after both you AND your unborn baby.

The average woman gains about 12kg during pregnancy. Water is a major contributor to the amount of weight you put on during this time – about 6-8 litres in fact – and is vital for the development of your baby. Even more surprisingly perhaps, your unborn baby is itself mostly water too with studies concluding that the water content of your baby during pregnancy is between 75-90%.

The increase of your total body water content during pregnancy assists the gradual growth of your baby and allows large volumes of water through the placenta. Emerging evidence is indicating that keeping well hydrated is thought to be very important for the health and development of your unborn baby.

Much more research needs to be done to help us understand exactly what keeping well hydrated in pregnancy can actually help mum (you) with too, but interest is increasing. Take constipation for example; about 40% pregnant women experience constipation and it’s thought that by keeping well hydrated (along with increasing dietary fibre), you may well help avoid constipation. A smaller number of pregnant women suffer urinary tract infections, but the evidence to support hydration offering some protection against developing a urinary tract infection is not yet clear. It is thought, however, that increased fluid intake may help ‘flush out’ bacteria in the urinary tract reducing the chance bacteria can take hold and cause an infection.

Ensuring that you are well hydrated may be a huge step forwards to offsetting some of the not so desirable and more common ailments that can occur in pregnancy. That has to be good news for all pregnant women as anyone who has suffered either problem in pregnancy will most certainly agree!

  • As the weather gets warmer and your fluid needs increase it’s vital you drink enough
  • Aim to drink an extra 300ml a day as a minimum and increase it as the temperature rises
  • Increase your water intake without increasing your calorie intake by flavouring your water with your favourite tasting zero-calorie sweetener – we know that Stevia is safe so that is quite ideal


  • Iom Institute of Medicine) National Acadamies of Science. Weight Gain during Pregnancy:re-examining the Guidelines. The National Acadamies Press, Washington DC, 2009
  • Chelsey LC. Hypertensive disorders in Pregnancy. New York: Appleton-Century-Crofts; 1978
  • Hytten FE. Weight gain in pregnancy. In: Hytten FE, Chamberlain G. Eds. Clinical Physiology in Obstetrics, Blackwell Scientific 1980:Oxford, pp. 193-230
  • Givens MH and Macy IG. The chemical composition of the human fetus. J. Biol. Chem., 1933, 102: 7-17
  • Ziegler EE, O’Donnell AM, Nelson SE, Fomon SJ. Body composition of the reference fetus. Growth. 1976; 40(4): 320-41
  • Cullen G, O’Donoghue D. Constipation and pregnancy. Best Pract Res Clin Gastrolenterol. 2007; 21(5):807-18

Pregnant and Breastfeeding Mothers

January 31st 2014

Think Flavour!

Pregnant women and breastfeeding mothers have increased water needs. When you first find you are pregnant, you may be one of the many women who experience morning sickness and the thought of eating and drinking anything at all may well seem impossible but it’s important for the health of you and your baby to try to drink (The majority of your baby’s weight at the end of the first trimester is water). Hopefully you don’t feel sick all day (why is it called ‘morning sickness’ some of you cry?!) but in any case, sipping small amounts of fluid as often as you can may be the best approach in those first few weeks. You need to drink 300ml (nearly 1/2 pint) water, on top of the additional 2 litres of water you are recommended to drink when you are not pregnant.

Water and Pregnancy

After your baby is born you should drink more to compensate for the fluid in the milk you produce to feed your baby. Dehydration may start to change the composition and amount of milk you produce, but don’t worry, a little dehydration is not really the problem and just drinking an extra 600-700ml every day should do the trick. Make it a habit to have a drink every time you sit down and feed your baby and drink it whilst you are your relaxing and enjoying your time together.

When you are pregnant and breastfeeding make a conscious effort to drink more than you did before you embarked on this wonderful journey. Remember it’s not just drinks that add to your daily fluid intake, foods do too. I’m sure you have many questions about what to drink but let’s just touch on caffeine for now; you can have caffeine in your daily diet but do think ‘moderation’. It’s tricky to measure how much you are actually having with any certainty as drinks and foods such as tea, coffee and chocolate contain caffeine, and, in varying amounts. That’s where flavoured water may help you drink more. Think flavour... flavoured water tastes great and makes a great change to plain water alone – try if for yourself and see.

Penny Hunking Registered Dietitian

-Penny Hunking RD, R.SEN, R.Nutr (Public Health)

From fuelling fitness for sports performance to healthy eating and fat loss, Penny Hunking has written, researched and talked to consumers and professionals about virtually every aspect of diet, weight management and exercise. She has also written or contributed to many books on key aspects of food, fat loss, fitness and special diets in a career spanning more than 3 decades.

Penny is a Registered Dietitian, a member of the British Dietetic Association, the Nutrition Society, Nutritionists in Industry, Association of Obesity and Sports Dietitians UK. But life is not all hard work, she is passionate about scuba diving, water skiing, cookery, travel and eating out.

RD – Registered Dietitian
R.SEN – Registered Sport and Exercise Nutritionist
R.Nutr – Registered Nutritionist (with a nutrition specialism in Public Health)