Pregnancy guidance, in plain English

Miso

Miso is safe during pregnancy. It's a fermented, salted soybean paste used in small quantities as a seasoning, and the fermentation process addresses the same phytoestrogen and food-safety questions sometimes raised about soy generally.

Safe to eat

Last updated: September 2026 Cross-checked against NHS guidance

Miso is a traditional Japanese paste made by fermenting soybeans, usually with salt and a mould culture (koji), sometimes combined with rice or barley — a process that can take anywhere from a few weeks to several years depending on the style. It's used in small amounts as a seasoning and flavour base, most commonly stirred into miso soup, marinades, and dressings, rather than eaten in large quantities on its own. As with soy generally, some pregnant women wonder whether miso's phytoestrogen content (plant compounds that weakly mimic oestrogen) is a concern — the evidence doesn't support this at normal dietary intake levels, and miso is used in exactly the small, seasoning-level quantities that make this a non-issue in practice. The main thing actually worth being mindful of with miso isn't food safety at all, but sodium: miso is quite salty, and using it generously — particularly in a soup alongside other salty ingredients — can add up across a meal, fitting with general pregnancy advice to keep an eye on overall salt intake rather than being a miso-specific rule. Commercially produced miso undergoes a controlled fermentation process and is safe to eat without any special preparation; there's no raw-food concern the way there is with, for example, unpasteurised dairy.

What to be aware of

  • Miso is safe throughout pregnancy — the fermentation process and small quantities used mean phytoestrogen concerns don't meaningfully apply.
  • Miso is high in sodium — use it in normal seasoning quantities rather than generously, particularly alongside other salty ingredients.
  • Choose commercially produced miso from a reputable source, for the same general quality-control reasons that apply to any fermented food.
  • Miso soup made with dashi (a fish-based stock) is fine — cooked fish stock doesn't carry the same concerns as raw fish.

What to eat instead

  • Tofu & Soy — A milder-tasting, less salty way to get similar soy-based nutrition.

Pregnancy-safe recipes

These recipes are designed with pregnancy safety in mind.

Image needed

A bowl of miso soup with tofu cubes, nori, and spring onions, steam rising, overhead food photography, warm natural light

Simple miso soup

A quick, comforting soup that showcases miso's savoury depth without overdoing the salt.

Pregnancy tip: Add the miso paste right at the end, off the boil — boiling miso can dull its flavour and destroy some of its beneficial fermentation compounds.

Ingredients

  • 600ml dashi or vegetable stock
  • 2 tbsp miso paste
  • 150g silken tofu, cubed
  • 1 sheet nori, torn
  • 2 spring onions, sliced

Method

  1. Heat the stock gently in a saucepan until just below boiling.
  2. Ladle a little hot stock into a small bowl with the miso paste and whisk until smooth.
  3. Remove the pan from the heat and stir the miso mixture back in.
  4. Add the tofu and nori and let sit for a minute to warm through.
  5. Serve immediately, topped with spring onions.