The effect of altitude on an unborn baby is the main concern of pregnant women considering a trek in Nepal, but other health issues matter just as much: long-haul air travel, travel in remote areas, the lack of adequate medical infrastructure in the country, and illnesses such as diarrhea. This article is meant to help you decide whether to travel to Nepal while pregnant — and, if you do, how to plan your trip to minimize the risk to you and your baby.
Air travel during pregnancy
The two main concerns are low oxygen and cosmic radiation. There is good experimental evidence that the low oxygen inside an airplane doesn't interfere with oxygen delivery to the unborn baby, as measured by fetal heart monitoring during flight. There is no evidence that babies are harmed by long-haul air travel, and for most casual travelers the effect of cosmic radiation is said to be negligible. Most airlines continue to allow pregnant cabin crew to work.
Reasons to consider not flying while pregnant:
- A previous history of miscarriage or premature labor or delivery
- Severe anemia
- Uncontrolled blood pressure
- A previous ectopic pregnancy without confirmation of where the current pregnancy is sited — usually a scan is needed to confirm it is in the womb
- A previous blood clot in the leg or the lung
Most airlines will not allow pregnant women to fly beyond 32 weeks. Thai Airways will usually allow women to fly from Kathmandu to Bangkok at 36 weeks with a letter from an obstetrician stating they are well and unlikely to deliver on the plane. An accompanying letter is mandatory for all pregnant women traveling by air.
Altitude and pregnancy
There is limited information on the effect of short-term exposure to high altitude on pregnant women and their babies. Most data comes from moderate altitude — for example, pregnant airline crew who regularly fly at cabin altitudes of up to 8,000 ft (2,438 m) and do fine with their pregnancies.
An unborn baby is expected to tolerate some degree of low oxygen quite well, up to around 12,000 ft (3,650 m), because the fetus routinely lives in a relatively low-oxygen environment. Progesterone, abundant in pregnancy, stimulates breathing, which helps a pregnant woman adapt to altitude. But acclimatization is genetically determined, and it isn't possible to predict how well any individual will respond. Pregnant women should never let themselves develop acute mountain sickness (AMS), or the more severe high altitude cerebral or pulmonary edema (HACE or HAPE).
Long-term exposure to altitude in pregnancy has been shown to slow fetal growth in high-altitude residents — though not in genetically protected populations such as Tibetans or Andeans. This is not a concern for short-term visitors.
Other considerations for the pregnant trekker
Isolation. Trekking in Nepal takes you into remote regions. The two most popular areas, Khumbu and the Manang valley in the Annapurna region, have health posts staffed by western doctors during the trekking seasons — placed where the risk of altitude illness is high, though they can also handle other emergencies. Virtually no other health facilities exist in other trekking areas; the only other medical help would be a passing doctor or evacuation to Kathmandu.
Diarrhea. The most common travel-related illness. See our article on diarrhea. Stay hydrated with oral rehydration solution.
Hepatitis E. A viral infection of the liver that causes jaundice. It is very like hepatitis A, with one exception: it seems to be particularly dangerous for pregnant women. It is prevalent in Nepal, there is no vaccine yet, and it spreads through contaminated water and food.
When to consider postponing
Trekking while pregnant carries some risk for both mother and child. Altitude alone may not be the greatest threat — there is good evidence that a brief period at moderate altitude, with time taken to acclimatize, is quite safe — but a host of other factors can make a trek in Nepal hazardous. Pregnancy is temporary, and the hills will be worth visiting for a long time to come. It may be safer, and more fun, to come back with your young child (see our article on trekking with children).
Consider postponing a trek if you:
- Have a history of miscarriage, especially in the first three months
- Have a concurrent medical condition, or smoke
- Are pregnant for the first time
- Have had a complicated pregnancy requiring hospital admission (other than for delivery)
If you do decide to trek
- Have at least one scan confirming the pregnancy is in the womb (beware a second pregnancy in one of the tubes) and that the placenta is not "in the way" — a placenta praevia.
- Make sure you aren't anemic, don't have high blood pressure and aren't developing diabetes. Have your urine checked for protein and sugar.
- Check that you are immune to rubella (German measles). It is rare in the West but not uncommon in Nepal, where MMR vaccine uptake is low, and it is very damaging to an unborn child.
- Ascend slowly and acclimatize well. Build in plenty of rest days, stay well hydrated, and descend promptly if you feel unwell (see our article on altitude illness).
- Get the best medical insurance you can, and make sure it covers evacuation off the trail and out of the country.
If you have any questions about pregnancy and trekking, please contact us.