Staying well hydrated is very important during pregnancy and even more so if you have diabetes whilst pregnant. Drinking water doesn’t directly lower blood sugar levels, but it does flush excess sugar out of your system, so staying hydrated will help control and stabilise blood sugar levels.

Ideally, you should be drinking around 2-3 litres (10 -12 glasses) at least a day. You will need to drink even more during warmer weather or if you are exercising.

I recommend drinking a glass of water with AND between every meal and snack during the day.

Golden rule No7 Drink Plenty & Stay Hydrated

Tea, coffee and fizzy drinks containing caffeine should not be included as part of your recommended daily fluid intake as they are diuretics. Diuretics make you urinate more frequently, causing you to lose water.  

If you don’t like the taste of water, you could try carbonated water with fruit such as lemon and lime.  Be careful when choosing diluting squash which has ‘no added sugar’; it means exactly that, no ADDED sugar, but it will still contain natural sugars.  Check labels for the lowest total carbs for the best choices.

What can I drink with gestational diabetes?

  • Water, carbonated or still. Beware of flavoured waters that may contain added sugars
  • Tea & coffee, decaffeinated or remember to include within your recommended daily intake of caffeine
  • Diet/Zero/No added sugar carbonated drinks (please note: most of these contain artificial sweeteners so it is advisable to drink as a treat, not on a daily basis)
  • No added sugar diluting squash (watch out for high juice or squashes with natural or concentrated fruit juices added)
  • Milk; whole (full-fat cow’s milk), lacto-free milk, no added sugar almond, soya, hemp seed or coconut milk, and kefir
  • Hot Chocolate: Try one of my recipes for regular hot chocolate or a dairy-free vegan version
  • Raspberry leaf tea (after 32 weeks gestation and not to be used if taking Metformin)

Caffeine in drinks

Be mindful that some carbonated drinks, coffee and tea contain caffeine.  Current guidelines recommend consuming no more than 200mg of caffeine per day during pregnancy​1​.

How much caffeine is in my drink?

The amount of caffeine found in some drinks is as follows:

  • one mug of instant coffee: 100mg
  • one mug of filter coffee: 140mg
  • one mug of tea: 75mg
  • one can of cola: 40mg
  • one can of energy drink: up to 80mg


Lactose, the naturally occurring sugar in milk, can have varied results in different people.  

It’s advisable to perform a ‘milk test’ if you want to consume larger amounts of milk

Have a glass of milk as a ‘snack’ (ensure you do not eat or drink anything else, so this will impact the results) and then test your blood sugar levels to see how it affects you after one hour.  If you get good results (below your one-hour post-meal target, below 7.8 mmol/L for most), you can tolerate milk; if you see high blood sugar levels, avoiding milk or swapping to a different type of milk is best.

simple carbs lactose from milk

Milk with a higher protein and fat content will help pair the carbs, making it more tolerable.

The table below compares 100ml of each type of milk. All the milk listed is fresh (chilled) milk, with dairy alternatives being Alpro UNSWEETENED milk drinks, with the exception of rice and hemp milk, which is long life. Note: 4g of carbs is equivalent to 1 teaspoon of sugar.

milk per 100mlcarbs (g)protein (g)fatcalcium (mg)
✔️ almond milk (no sugars, Alpro)00.41.1120
✔️ soya milk (no sugars, Alpro)03.31.8120
✔️ hemp seed milk (Good Hemp)
✔️ lacto-free whole milk2.63.33.6108
✔️ coconut milk (no sugars, Alpro)
✔️ hazelnut milk (Alpro)
✔️ Arla BOB semi-skimmed milk4.64.61.7150
✔️ Graham’s gold top4.73.75.0134
✔️ whole milk4.73.53.7124
❌ semi-skimmed milk4.83.61.8124
❌ Arla BOB skimmed milk4.94.60.4147
❌ skimmed milk5.03.60.3130
❌ 1% milk5.03.61.0127
❌ oat milk (no sugars, Alpro)
❌ rice milk (no added sugars, Tilda)

[Information taken from Tesco and Waitrose websites, correct June 2023]

Milk in tea and coffee

A splash of milk in tea or coffee should not impact blood sugar levels. Still, if you drink very milky tea or coffee, or when drinking larger amounts of milk, you should include this drink within your meal or snack and incorporate this within your test times, i.e. avoid eating and drinking these things before testing your one-hour blood sugar level.

Sugar-free and zero drinks

There are a plethora of sugar-free, zero and no-added-sugar drinks available to purchase now. However, the majority of these drinks contain artificial sweeteners.

Some artificial sweeteners have been found to raise blood sugar levels and increasing evidence is also showing other concerns over consumption during pregnancy.

Are sweeteners safe for consumption in pregnancy?

In the UK sweeteners are deemed as being safe for use in pregnancy. In the Policy Statement, The Use of Artificial Sweeteners, The BDA (The British Dietetic Association) states:

Artificial sweeteners are considered safe for consumption during pregnancy. However, foods and drinks containing artificial sweeteners should not replace more nutritious options (e.g., the consumption of ‘diet’ drinks in replacement of milk-based drinks or fruit juice).​2​

sweeteners in pregnancy

More recent evidence-based research is showing a concern related to the consumption of artificial sweeteners in pregnancy and the impact on the child

Research suggests links between consumption of artificially sweetened soft drinks and the risk of pre-term delivery in Danish pregnant women​​​3​.

Whilst sweeteners in pregnancy may be deemed safe for consumption, there is increasing evidence suggesting that consuming artificial sweeteners in pregnancy leads to changes in metabolism and gut microbiome, causing metabolic modifications which can lead to increased BMI and increased insulin resistance in the child born to the mother who has consumed them​4–12​.

Some sweeteners in pregnancy are safer than others, with some artificial sweeteners being linked to concerns for both the health of the mother and the child in later life.

If you would like to use sweeteners in pregnancy as an alternative to sugars due to diabetes, the safest options are naturally derived sweeteners. Opt for 100% pure stevia, or stevia and erythritol blended products such as NatviaTruvia and Pure Via, and/or polyols such as pure erythritol such as NKD Living erythritol, or Sukrin, and Total Sweet xylitol which have no or little impact on blood glucose levels, do not cause a negative impact on the gut microbiome and have shown no negative impacts to the longer-term health of the mother or child.

recommended sweeteners

Watch out for artificially sweetened foods and beverages such as diet and zero drinks, consuming them as ‘treats’ rather than part of your typical daily diet. Beware of consuming sweeteners in large amounts as the majority will cause gastric upset.


Coffee shop conundrum

When standing in a coffee shop or café looking at the drinks menu you may feel completely daunted and confused as to what to choose.

Decaffinated tea or coffee without milk and syrup is the best option, however, for those that enjoy milky drinks such as lattes, you could opt for whole (full-fat) milk which will help pair the carbs and opt for a sugar-free syrup.

Watch out for milk alternatives such as soya and almond which may have added sugars, avoid oat and rice milk completely due to the much highercarb content and also beware of whipped cream which may also contain added sugar too.

Iced fruit smoothies, iced coffees & coolers

Unfortunately these icy, refreshing and fruity drinks can also be packed with sugar. Not such a big surprise when we know that fruit itself and even more so, fruit juice and sweet syrups can spike levels very high, very quickly.

drinks comparedcarbsproteinfat
✔️ Tango Ice Blast (sugar-free blue raspberry, cherry, or mexican lime)000
✔️ Costa iced americano (small, 359ml)5.20.8 0.1
✔️ Costa watermelon & mint refresher (medium, 365ml) 8.400
✔️ Costa blood orange & yuzu refresher (medium, 365ml) 8.80 0.2
✔️ Costa Fuze tea peach hibiscus iced tea (medium, 438ml) 10.9 00
✔️ Costa still lemonade (medium, 357ml) 12.200
✔️ Costa iced latté (small, 364ml) 13.1 6.6 6.9
✔️ McDonald’s iced latté (regular)
✔️ Costa iced cappuccino (medium, 325ml) 16.85.5 3.1
✔️ Costa coffee frappé (small, 378ml) 20.4 6.2 17
❌ Costa mango & passionfruit cooler (small, 400ml) 28.1 1.3 0.6
❌ McDonald’s strawberries & cream frappé (regular)294.610
❌ Costa strawberry lemonade (medium, 395ml) 29.6 0 0.4
❌ Costa mango berry bubble tea (medium, 414ml) 30.40.2 0
❌ Costa salted caramel frappé (small, 380ml) 31.1 5.5 10.8
❌ Costa salted caramel frappé with coffee (small, 355ml) 31.4 4 10.3
❌ Costa popcorn frappé & light whip (small, 368ml) 31.8 2.5 10.2
❌ Costa strawberries & cream frappé (small, 378ml) 33.6 5.8 17.3
❌ Costa chocolate fudge brownie frappé mocha (small, 357ml) 37.6 4.9 9.4
❌ McDonald’s caramel iced frappé (regular)38.06.416
❌ Costa chocolate fudge brownie frappé (small, 382ml) 40.5 3.7 11.5
❌Costa red summer berries cooler (small, 400ml) 41.8 00
❌ McDonald’s mango & pineapple smoothie (regular)
❌ Costa tropical mango bubble frappé (small, 403ml) 44.4 2.5 9.4
❌ Costa blueberry bubble frappé & light whip (small, 403ml) 47.8 2.2 9.4
❌ McDonald’s frozen strawberry lemonade (regular)

[Information taken from Costa, Odeon & McDonald’s websites. Information correct, 06/2023]

Ice cream milkshakes

All I can say is walk the other way!

Ice cream milkshakes should come with a huge sugar warning sign on them! These thick, creamy milkshakes can contain anything from 66g – 90g of total carbs for a medium or large serving!

There is a HUGE 90g of carbs in a large banana flavoured McDonald’s milkshake is the equivalent of 22 ½ tsp of sugar!!

Lower-carb milkshake options

In the last few years we have seen the launch of some much lower sugar milkshake alternatives. Yazoo has launched a no added sugar range in strawberry, banana and toffee flavours and Crusha liquid that you add to milk is now no added sugar too.

Yazoo contains lactose (natural sugars from the milk), but if you tolerate milk well, then you should tolerate these milkshakes fine too.

Don’t forget that you can also easily make your own milkshakes. Try out some of my recipes below:

Thick Vanilla Shake
Just like melted ice cream, this thick vanilla ice cream shake is to die for on a hot sunny day!
Check out this recipe
thick vanilla shake
Thick Chocolate Shake
A thick chocolate shake made with ice cream and my sugar-free chocolate syrup
Check out this recipe
thick chocolate shake
Thick Strawberry Shake
A thick strawberry ice cream milkshake but with no added sugars, the perfect snack on a hot sunny day!
Check out this recipe
thick strawberry shake
Chocolate Peanut Butter Shake
A thick chocolate milkshake that works great for chocolate lovers as a snack on sunny days and it's also vegan!
Check out this recipe
chocolate peanut butter shake
Lime and Coconut Smoothie
You put the lime in the coconut and drink it all up!
Check out this recipe
lime and coconut smoothie

Non-alcoholic versions of alcoholic drinks

Be wary of non-alcoholic drinks as many contain high amounts of sugar, especially ciders, wines and mocktails. Mocktails etc. contain a lot of fruit juices which are very high in natural sugars.

Fake Pimms
Fake Pimms | Non-alcoholic | Gestational Diabates UK
Check out this recipe
Fake Pimms
Fake Pimms
Citrus Refresher
Citrus Refresher | A refreshing citrus drink to enjoy on hot summer's days | Gestational Diabetes UK
Check out this recipe
Citrus Refresher

Drinks to avoid, these drinks can raise blood sugar levels very fast!

  • ❌ Pure or concentrated fruit juices eg. orange, apple, pineapple, mango, cranberry juice etc.
  • ❌ Ready-to-drink full-sugar fruit juices eg. Oasis, Ribena
  • ❌ Diluting squash e.g. full-sugar versions of orange squash, Ribena, high-juices
  • ❌ Full-sugar carbonated drinks e.g. Coke/Pepsi, Ginger beer, Irn-Bru, Lilt, Lemonade, Tango
  • ❌ Sports & energy drinks e.g. full-sugar Lucozade, isotonic drinks, Red bull, protein shakes/drinks
  • ❌ Milkshakes e.g. Yopp, Frijj, MacDonalds and Burger King milkshakes
  • ❌ Smoothies e.g. Innocent fruit smoothies
  • ❌ Iced coffees and coolers with added syrups
  • ❌ Hot chocolate e.g. full-sugar hot chocolates
  • ❌ Coconut water
  • ❌ Adding teapoons of sugar, honey or syrup to tea & coffee, or other drinks


  1. 1.
    Caffeine in pregnancy. The Royal College of Midwives, RCM Expert Clinical Advisory Group (ECAG) briefing. Published 2020. Accessed June 2023.
  2. 2.
    BDA The Association of UK Dietitians. Policy Statement The Use of Artificial Sweeteners. Published November 2016. Accessed June 2023.
  3. 3.
    Halldorsson TI, Strøm M, Petersen SB, Olsen SF. Intake of artificially sweetened soft drinks and risk of preterm delivery: a prospective cohort study in 59,334 Danish pregnant women. The American Journal of Clinical Nutrition. Published online September 2010:626-633. doi:10.3945/ajcn.2009.28968
  4. 4.
    Goran MI, Plows JF, Ventura EE. Effects of consuming sugars and alternative sweeteners during pregnancy on maternal and child health: evidence for a secondhand sugar effect. Proc Nutr Soc. Published online December 3, 2018:262-271. doi:10.1017/s002966511800263x
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    Sharma A, Amarnath S, Thulasimani M, Ramaswamy S. Artificial sweeteners as a sugar substitute: Are they really safe? Indian J Pharmacol. Published online 2016:237. doi:10.4103/0253-7613.182888
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    Azad MB, Sharma AK, de Souza RJ, et al. Association Between Artificially Sweetened Beverage Consumption During Pregnancy and Infant Body Mass Index. JAMA Pediatr. Published online July 1, 2016:662. doi:10.1001/jamapediatrics.2016.0301
  7. 7.
    Ali F. Consumption of artificial sweeteners in pregnancy increased overweight risk in infants. Arch Dis Child Educ Pract Ed. Published online February 8, 2017:277-277. doi:10.1136/archdischild-2017-312618
  8. 8.
    Archibald A, Dolinsky V, Azad M. Early-Life Exposure to Non-Nutritive Sweeteners and the Developmental Origins of Childhood Obesity: Global Evidence from Human and Rodent Studies. Nutrients. Published online February 10, 2018:194. doi:10.3390/nu10020194
  9. 9.
    Olivier-Van Stichelen S, Rother KI, Hanover JA. Maternal Exposure to Non-nutritive Sweeteners Impacts Progeny’s Metabolism and Microbiome. Front Microbiol. Published online June 20, 2019. doi:10.3389/fmicb.2019.01360
  10. 10.
    Laforest-Lapointe I, Becker AB, Mandhane PJ, et al. Maternal consumption of artificially sweetened beverages during pregnancy is associated with infant gut microbiota and metabolic modifications and increased infant body mass index. Gut Microbes. Published online December 31, 2020. doi:10.1080/19490976.2020.1857513
  11. 11.
    Zhu Y, Olsen SF, Mendola P, et al. Maternal consumption of artificially sweetened beverages during pregnancy, and offspring growth through 7 years of age: a prospective cohort study. International Journal of Epidemiology. Published online June 6, 2017:1499-1508. doi:10.1093/ije/dyx095
  12. 12.
    Azad MB, Archibald A, Tomczyk MM, et al. Nonnutritive sweetener consumption during pregnancy, adiposity, and adipocyte differentiation in offspring: evidence from humans, mice, and cells. Int J Obes. Published online May 4, 2020:2137-2148. doi:10.1038/s41366-020-0575-x