# Day 170: The glucose drink

> Most women are screened for gestational diabetes between 24 and 28 weeks. Which test you'll have, whether to fast, and what to pack for the wait.

- Series: Your sixth month of pregnancy, day by day (https://chorevia.com/learn/pregnancy-month-6), day 170 of 280, 24 weeks + 2 days
- Your baby this week: about the size of a corn on the cob; around 30 cm from head to heel
- Canonical URL: https://chorevia.com/learn/pregnancy-month-6/day-170
- Last reviewed: 2026-10-22
- Publisher: Chorevia (https://chorevia.com)
- Cite as: Chorevia. "Day 170: The glucose drink." Last reviewed October 22, 2026. https://chorevia.com/learn/pregnancy-month-6/day-170

This guide is general education that summarizes published research and guidance from groups like the American Academy of Pediatrics, the CDC, and the WHO. It isn’t medical advice, and every child develops on their own timeline. Your pediatrician knows your child; if something feels wrong, call them. In an emergency, call 911.

Twenty-four weeks and two days. Somewhere in the next month you'll be offered a sweet drink and a blood test. Today you find out which version, and plan the morning around it.

## Your baby

Your baby is around 30cm long from head to heel, about the size of a corn on the cob ([NHS](https://www.nhs.uk/best-start-in-life/pregnancy/week-by-week-guide-to-pregnancy/2nd-trimester/week-24/)). By 24 weeks the fetus sleeps and wakes on a regular schedule ([NICHD](https://www.nichd.nih.gov/health/topics/pregnancy/conditioninfo)), which is why some hours of your day feel busier than others.

## Your body

Gestational diabetes usually develops around the 24th week and often causes no symptoms, which is why it's tested for rather than waited for ([CDC](https://www.cdc.gov/diabetes/about/gestational-diabetes.html)). Most women are screened between 24 and 28 weeks, earlier if the risk is high ([MedlinePlus](https://medlineplus.gov/ency/article/007562.htm)).

There are two common ways to do it ([MedlinePlus](https://medlineplus.gov/ency/article/007562.htm)):

- **Two-step:** you drink a glucose drink and blood is drawn 1 hour later. A result at or below 140 mg/dL is normal. If it's higher, you're asked back for a longer follow-up test.
- **One-step:** a 75-gram glucose drink, with blood drawn before it and at two 60-minute intervals. Allow at least 2 hours.

For the one-step test and the longer follow-up, you don't eat for 8 to 14 hours beforehand or during the test ([MedlinePlus](https://medlineplus.gov/ency/article/007562.htm)). The Office on Women's Health puts the glucose tests at 26 to 28 weeks and says nothing but sips of water for 14 hours before the tolerance test ([OWH](https://womenshealth.gov/pregnancy/youre-pregnant-now-what/prenatal-care-and-tests)).

## Try today

### The glucose-drink day

- **Time:** 10 minutes

1. Ask your provider which test you're having, one-step or two-step, and whether you need to fast ([MedlinePlus](https://medlineplus.gov/ency/article/007562.htm)).
2. Book it. If you're fasting, take the earliest slot, so most of the fast happens while you're asleep.
3. Pack a snack for afterwards, water, and something to do for the wait.
4. If you're fasting, arrange a lift home or someone to meet you, in case you feel wobbly.

**Make it work:** Write the test name and the fasting rule in the appointment itself, not in your head. The morning of a fasting test is not when you want to be checking.

## Watch for

- **Normal:** a moment of dizziness, which the NHS lists for these weeks ([NHS](https://www.nhs.uk/best-start-in-life/pregnancy/week-by-week-guide-to-pregnancy/2nd-trimester/week-21/)). **Call your provider** for dizziness or fainting; the CDC lists it as an urgent warning sign ([CDC](https://www.cdc.gov/hearher/maternal-warning-signs/index.html)).
- **Normal:** nausea that hasn't fully gone; some women have it the whole pregnancy ([MedlinePlus](https://medlineplus.gov/ency/patientinstructions/000604.htm)). **Call your provider** for severe nausea and throwing up, especially if you can't drink for more than 8 hours or eat for more than 24 ([CDC](https://www.cdc.gov/hearher/maternal-warning-signs/index.html)).
- **Normal:** no symptoms of gestational diabetes at all, which is common ([CDC](https://www.cdc.gov/diabetes/about/gestational-diabetes.html)). **Call your provider** if you notice more thirst or need to urinate more often than usual, the mild symptoms the CDC describes, and haven't been tested yet ([CDC](https://www.cdc.gov/diabetes/about/gestational-diabetes.html)).

## For you

If the first result comes back high, hold on to this: about 2 out of 3 women who take the follow-up test do not have gestational diabetes ([MedlinePlus](https://medlineplus.gov/ency/article/007562.htm)). A recall is a second look, not a diagnosis.

And if it does turn out to be gestational diabetes, it's common, between 5% and 9% of US pregnancies each year ([CDC](https://www.cdc.gov/diabetes/about/gestational-diabetes.html)), and most women control their blood sugar with a healthy meal plan ([OWH](https://womenshealth.gov/pregnancy/youre-pregnant-now-what/pregnancy-complications)).

If you're the partner: on a fasting morning, be the lift. Bring the snack, hold the bag, and drive home.

## Sources

- NHS. "Week 24." Week-by-week guide to pregnancy, Best Start in Life. https://www.nhs.uk/best-start-in-life/pregnancy/week-by-week-guide-to-pregnancy/2nd-trimester/week-24/
- National Institute of Child Health and Human Development. "About Pregnancy." National Institutes of Health. https://www.nichd.nih.gov/health/topics/pregnancy/conditioninfo
- Centers for Disease Control and Prevention. "Gestational Diabetes." https://www.cdc.gov/diabetes/about/gestational-diabetes.html
- MedlinePlus. "Glucose screening tests during pregnancy." National Library of Medicine. https://medlineplus.gov/ency/article/007562.htm
- Office on Women's Health. "Prenatal care and tests." U.S. Department of Health and Human Services. https://womenshealth.gov/pregnancy/youre-pregnant-now-what/prenatal-care-and-tests
- NHS. "Week 21." Week-by-week guide to pregnancy, Best Start in Life. https://www.nhs.uk/best-start-in-life/pregnancy/week-by-week-guide-to-pregnancy/2nd-trimester/week-21/
- Centers for Disease Control and Prevention. "Urgent Maternal Warning Signs and Symptoms." HEAR HER campaign, 2024. https://www.cdc.gov/hearher/maternal-warning-signs/index.html
- MedlinePlus. "Morning sickness." National Library of Medicine. https://medlineplus.gov/ency/patientinstructions/000604.htm
- Office on Women's Health. "Pregnancy complications." U.S. Department of Health and Human Services. https://womenshealth.gov/pregnancy/youre-pregnant-now-what/pregnancy-complications