Can you eat som tam while pregnant? The problem isn't the papaya, it's the fermented fish and raw crab

Whenever morning sickness hits, som tam is the first thing that pops into your head, right? Sour, spicy and so refreshing. But the moment you go to order, an elder chimes in: “Green papaya? You’ll miscarry!”

There is some truth in this, and some of it is a bit overstated. Let’s look plainly at what the evidence says, and at the things on a plate of som tam you really do need to watch, which very often aren’t the papaya strands but what gets pounded in with them.

Can you eat som tam while pregnant?

Quick Answer: Yes, if you choose a recipe without raw ingredients or fermented ingredients that haven’t been heated, and eat from a clean stall.

But the different kinds of som tam carry very different levels of risk:

Type	Main risk	Advice
Som tam Thai (dried shrimp, peanuts)	How clean the vegetables and mortar are	Good choice, the safest in the group
Som tam with cooked pla ra	Saltiness	OK to eat, ask the stall to make sure it’s cooked
Som tam with raw pla ra	Liver fluke	Skip during pregnancy
Som tam pu (pickled crab, raw rice-field crab)	Lung fluke, Vibrio bacteria	Skip during pregnancy, or ask for boiled crab
Som tam with pickled or raw shellfish	Germs from raw shellfish	Skip during pregnancy

Why is raw pickled crab the problem?

Quick Answer: Because raw crab may carry both parasites and bacteria, and salt pickling doesn’t make it as safe as cooking it.

The Centre for Food Safety in Hong Kong explains:

• Freshwater crabs, such as rice-field crabs (pu na), may carry lung flukes, which cause diarrhea and stomach pain, followed by fever and chest pain, and sometimes the parasite can travel to the brain
• Sea crabs and brackish-water crabs may carry Vibrio bacteria, which cause diarrhea, vomiting, fever and stomach pain within 1 to 2 days

At the same time, the CDC and NHS advise pregnant women to avoid all raw or undercooked seafood, because the immune system changes during pregnancy, making it easier to pick up infections from food. If you really miss the taste of som tam pu, try asking the stall to use boiled crab instead.

What is the difference between raw pla ra and cooked pla ra?

Quick Answer: Raw or under-fermented pla ra carries a risk of liver fluke, while pla ra sauce that has been boiled reduces this risk.

The Department of Disease Control warns that eating raw or undercooked freshwater fish, including undercooked pla ra and pla som (fermented fish), carries a risk of liver fluke, which is a leading cause of bile duct cancer in Thailand. It stresses that squeezing lime, adding chili or eating it with alcohol does not kill the parasites. Only heat does.

These days many stalls use boiled pla ra sauce, or bottled pla ra that has already been heat-treated. If you’re not sure, just ask the vendor. It isn’t rude. If you ask and still aren’t sure, ordering som tam Thai is the more relaxing choice.

Does green papaya really cause miscarriage?

Quick Answer: There is no research in humans confirming that eating normal amounts of som tam causes miscarriage. The concern comes from animal studies on papaya latex, not the papaya flesh that goes into an ordinary som tam.

We want to tell this as accurately as the available evidence allows:

• The study most often cited was done in lab rats, published in the British Journal of Nutrition in 2002, and asked directly whether the belief about papaya and pregnancy is “fact or fable.” In short, it found no harm from ripe papaya in normal amounts, but highly concentrated latex from unripe or semi-ripe papaya made the uterus contract in the experiment. So the researchers took the view that unripe or semi-ripe papaya may not be safe for pregnant women
• Other lab studies also tested latex or extracts directly on animal uterine muscle, in amounts and forms very different from eating a plate of som tam
• There is no good research in humans yet, either saying it is dangerous or saying it is 100% safe

So the elders aren’t saying it out of nowhere, but it also doesn’t mean that anyone who has already eaten som tam will miscarry. No need to panic.

A realistic middle ground:

• Eat it occasionally, enough to satisfy the craving, not a big bowl every day
• Most stalls peel and wash the papaya before shredding it, which helps reduce the latex. If you make it yourself, rinse the strands in several changes of water
• Don’t consume papaya latex, freshly squeezed green papaya juice, or papaya extracts or herbal medicines during pregnancy
• If you have a history of miscarriage, bleeding, or your doctor has said your pregnancy is high-risk, talk to your doctor first, or skip it for now for peace of mind

Do you need to watch out for cleanliness, spice and salt?

Quick Answer: Yes. Even without raw ingredients, som tam is fresh food that isn’t heated, so how clean the stall is matters.

• Cleanliness: fresh vegetables, and a mortar that is also used for raw ingredients, can be contaminated with germs. The CDC advises pregnant women to avoid unwashed fruit and vegetables. Choose a stall that looks clean and makes it fresh in front of you
• Left out too long: som tam that has been made and left sitting in hot weather for several hours shouldn’t be eaten
• Spice isn’t dangerous to your baby, but may cause heartburn or diarrhea. Cut down the chili to what your body can handle
• Salt: pla ra sauce and salted crab are high in sodium. If your doctor says your blood pressure is starting to rise or you are very swollen, try ordering it milder

Go to hospital now if…

Quick Answer: If you have a fever, vomit or have diarrhea so badly you can’t keep fluids down, or have pregnancy-related symptoms as well, go to the hospital handling your prenatal care.

• Fever, chills or body aches after eating raw or fermented food
• Severe vomiting or diarrhea, to the point where you can’t keep fluids down, have a dry mouth, and are peeing less
• Blood in your stool, or severe stomach pain
• Vaginal bleeding, or your belly tightening on and off
• Your baby is moving less than usual
• A cough, chest pain or fever in the weeks after eating raw crab

If you have had severe nausea and vomiting since the first trimester that has nothing to do with food, read more in How bad does morning sickness have to be before you see a doctor?, and the full overview of foods to avoid is in What can’t you eat when pregnant? And if you regularly have your som tam with a large Thai iced tea, have a look at how to count caffeine in Can you drink coffee while pregnant? too.

A summary you can order with

“Som tam Thai, or som tam with cooked pla ra, no raw crab, not too spicy” (ตำไทย หรือตำปลาร้าต้มสุก ไม่ใส่ปูดิบ พริกน้อย). That’s all it takes to enjoy it without sitting there worrying. Craving som tam in pregnancy is completely normal. Choose well, and enjoy every bite.