Yes, most experts consider diet soda acceptable in pregnancy if you drink it in moderation and stay within caffeine limits, but it is not the healthiest choice and there are some questions about possible risks.

Key points

• Aim to keep total caffeine under about 200 mg per day during pregnancy; a 12‑oz can of many diet colas has roughly 35–50 mg, so factor that into your daily total from coffee, tea, and chocolate.

• Most commonly used artificial sweeteners such as aspartame, sucralose, and acesulfame‑K are generally regarded as safe in pregnancy when used in moderate amounts, while saccharin is usually the one that some organizations suggest avoiding because it crosses the placenta and is less well studied.

• Several observational studies have linked frequent intake of diet sodas or artificially sweetened drinks in pregnancy with higher risks of gestational diabetes, preterm birth, higher birth weight, or later childhood obesity, but these studies do not prove cause and effect and the evidence is still considered mixed and emerging.

Practical advice

• If you choose to drink diet soda, limit it to an occasional can rather than daily multiple servings, and prioritize water, sparkling water, milk, or small amounts of juice for routine hydration.

• Check the label for caffeine content and the type of sweetener, and avoid going over the daily caffeine limit once all sources are added up.

• If you have or are at risk for gestational diabetes, high blood pressure, or excessive weight gain, discuss diet soda and other sweetened beverages specifically with your prenatal clinician, since recommendations may be stricter in those situations.

If you tell what brand and how much you typically drink, a tailored “safe amount” can be estimated to discuss with your doctor or midwife.