Is it appropriate to administer 5% dextrose in 0.9% saline (dextrose normal saline) to a pregnant woman?

Yes, dextrose normal saline (DNS) can be given to pregnant women, but normal saline alone is preferred for most situations.

For pregnant women requiring IV hydration (particularly in hyperemesis gravidarum), normal saline (0.9% NaCl) with additional potassium chloride is the most appropriate choice, not dextrose-containing solutions 1. This represents the current standard of care based on the most recent 2024 guidelines from the Royal College of Obstetricians and Gynaecologists.

Key Clinical Considerations

When DNS is Acceptable

• During labor induction: DNS may actually reduce labor duration. A 2017 trial showed that 5% dextrose in normal saline reduced total labor length by approximately 76 minutes compared to saline alone (499 vs 423 minutes, P=0.024) without increasing complications 2
• General hydration during labor: When oral intake is restricted, higher infusion rates (250 mL/hour) of IV fluids shortened labor duration 3

When to Avoid or Use Cautiously

Critical safety concern: Large amounts of dextrose immediately before delivery can cause:

• Fetal hyperglycemia and hyperinsulinemia
• Neonatal hypoglycemia (as low as 1.8 mmol/L)
• Neonatal jaundice
• Fetal acidosis (pH 7.19)
• Delayed neonatal glucagon release 4

The threshold appears to be around 25-57.5g of dextrose given rapidly - amounts exceeding 6g/hour should be avoided near delivery 4.

For Hyperemesis Gravidarum Specifically

Use normal saline, not DNS. A 2013 randomized trial comparing 5% dextrose-0.9% saline versus 0.9% saline alone found:

• No difference in resolution of ketonuria (9.9% vs 10.9%)
• No difference in well-being scores
• Only marginal nausea improvement at 8-16 hours that disappeared by 24 hours
• No difference in length of hospitalization 5

Critical warning from guidelines: Thiamine supplementation (100mg TDS orally or IV Pabrinex) must be given to all women with vomiting or severely reduced dietary intake before administering dextrose or parenteral nutrition to prevent Wernicke's encephalopathy 1.

Practical Algorithm

For hyperemesis gravidarum:

1. Give thiamine FIRST
2. Use normal saline 0.9% with added KCl (guided by daily electrolytes)
3. Monitor electrolytes daily
4. Avoid dextrose solutions

For labor/delivery:

1. If using IV fluids during labor induction, DNS at 125-250 mL/hour is acceptable and may shorten labor
2. Limit dextrose to <6g/hour if delivery is imminent
3. Avoid large dextrose boluses (>25g) near delivery time

General pregnancy IV hydration:

• Normal saline is the default choice
• DNS is not contraindicated but offers no clear advantage in most situations
• The FDA label notes dextrose "should be given to a pregnant woman only if clearly needed" 6

Bottom Line

While DNS is not absolutely contraindicated in pregnancy, normal saline is preferred for most clinical scenarios, particularly hyperemesis gravidarum. If DNS is used during labor, keep the dextrose rate below 6g/hour and avoid large amounts near delivery to prevent neonatal complications.