High-Altitude Medical

HANDBOOK

Women acclimatize to altitude in much the same way as men. No significant differences in respiratory acclimatization between sexes have been demonstrated, even though progesterone increases ventilation and the ventilatory response to hypoxia. The incidence of Acute Mountain Sickness (AMS) in women is also similar to that in men.

The occurrence of AMS does not depend on the phase of the menstrual cycle. Some sources indicate that High Altitude Pulmonary Edema (HAPE) occurs less frequently in women than in men. However, swelling of the face or lower limbs tends to affect women more often. There is currently no evidence that High Altitude Cerebral Edema (HACE) presents differently in women.

HYGIENE AND PRACTICAL TIPS

In mountain conditions, urination can be difficult, especially inside a tent. A bottle with a wide opening or a device such as a “she-wee” can be very helpful.

To make hygiene easier during menstruation, some women choose to trim or shave pubic hair. It is also advisable to carry medications for:

➤ urinary tract infections

➤ vaginal infections

➤ urinary incontinence

MENSTRUATION AT ALTITUDE

The timing of menstruation may change at altitude. Factors that can influence the cycle include:

➤ sudden changes in time zones (jet lag)

➤ intense physical effort

➤ cold exposure

➤ weight loss

Menstruation can be particularly inconvenient during expeditions where access to sanitation facilities is very limited.

To avoid bleeding during an expedition, some women choose to take combined contraceptive pills continuously without a break for several months. However, spotting or breakthrough bleeding may occur during the first three months.

Alternative options based on progesterone include:

➤ the mini-pill

➤ medroxyprogesterone injections

➤ contraceptive implants

➤ hormonal intrauterine devices (IUDs)

Cycle regulation should ideally be planned about six months before the expedition.

If menstrual bleeding is heavy, significant amounts of iron may be lost. In such cases it is advisable to consult a doctor about iron supplementation. During acclimatization the body increases red blood cell production, which requires adequate iron stores. Iron reserves, often assessed by serum ferritin levels, should therefore be optimized before the trip.

CONTRACEPTION IN THE MOUNTAINS

There is no evidence that altitude reduces the effectiveness of the following contraceptive methods:

➤ oral contraceptive pills

➤ contraceptive injections

➤ diaphragms

➤ female condoms

➤ intrauterine devices (IUDs)

However, in expedition conditions—where meals, sleep, and routines may be irregular—the effectiveness of contraception may be slightly reduced.

It is also important to remember that broad-spectrum antibiotics (such as penicillins or tetracyclines) may decrease the effectiveness of oral contraceptive pills containing less than 50 µg of estrogen. During antibiotic therapy and for 7 days afterward, an additional contraceptive method should be used.

It is not clearly established whether hormonal contraception affects the acclimatization process.

Combined oral contraceptives (except progesterone-only preparations) may increase the risk of deep vein thrombosis (DVT) and pulmonary embolism, particularly when combined with dehydration, cold exposure, prolonged immobility, and increased blood viscosity. This risk may increase after about a week above 4500 m (14,700 ft), especially in smokers or women with low physical fitness.

For this reason, progesterone-only contraception is often recommended. Contraceptive planning should ideally begin about six months before the expedition.

PREGNANCY AND ALTITUDE

Pregnant women are not necessarily at higher risk of altitude illness. However, hypoxia can interfere with circulation between the placenta and the fetus, potentially leading to fetal hypoxia.

At altitude, blood flow through the uterus decreases, which may reduce the oxygen supply available to the fetus. Intense physical exertion by the mother may further reduce oxygen availability, as muscles compete with the fetus for oxygen and blood flow.

Pregnant women are also more susceptible to dehydration. Both pregnancy and altitude increase breathing rate and depth, and breathing dry mountain air increases fluid loss.

Long-term stays (weeks or months) above 2500 m (8200 ft) may increase the risk of complications such as:

➤ vaginal bleeding

➤ premature placental abruption

➤ hypertension and preeclampsia

➤ premature birth

➤ intrauterine growth restriction

➤ intrauterine fetal death

Additional challenges during expeditions include distance from medical care, limited diagnostic and treatment options, increased risk of injury, and travel-related infections. Some diseases, such as malaria or hepatitis E, may have a more severe course during pregnancy.

Many medications used for altitude illness prevention or malaria prophylaxis are contraindicated during pregnancy. This includes acetazolamide, which should not be used during the first trimester or after 36 weeks of pregnancy.

ALTITUDE DURING DIFFERENT STAGES OF PREGNANCY

There is some evidence that altitude may increase the risk of spontaneous miscarriage in the first trimester. For this reason, travel to high mountains during this period is generally discouraged, particularly for women with increased miscarriage risk.

After the first trimester, women with a low-risk pregnancy may stay briefly at altitudes up to about 2500 m (8200 ft). After 2–3 days of acclimatization, moderate physical activity may be possible, although intense exertion should be avoided.

Travel to altitude is generally not recommended after 20 weeks of pregnancy if any of the following conditions are present:

➤ hypertension

➤ preeclampsia

➤ anemia

➤ maternal smoking

➤ fetal growth restriction

➤ maternal heart or lung disease

If a prolonged stay at altitude is unavoidable, regular medical monitoring is recommended, including ultrasound examinations, blood pressure measurements, and fetal development assessment.

PHYSICAL ACTIVITY DURING PREGNANCY

During the first trimester there are usually no contraindications to moderate activities such as climbing or skiing at low altitude (near sea level). When climbing, a full-body harness should be used to avoid pressure on the abdomen.

In later stages of pregnancy, climbing and skiing are generally discouraged. Increased body weight, changes in the center of gravity, and greater joint laxity may increase the risk of falls, injuries, and potential complications affecting the placenta.

SUMMARY

➤ Women acclimatize to altitude similarly to men.

➤ Menstruation, contraception, and hygiene require advance planning for mountain trips.

➤ Contraception and menstrual cycle management should ideally be planned several months before departure.

➤ Pregnant women should plan altitude travel very carefully and consult a physician beforehand.

Proper medical and logistical preparation allows women to safely pursue ambitious mountain objectives.

-------

WANT TO LEARN MORE?

If you want to better prepare your health for trekking or a high-altitude expeditions, check out the expanded guide in the ebook "High-Altitude Medicine for Trekkers and Climbers" >>

-----

Gain practical skills for handling emergencies in the mountains through our online training "High-Altitude First Aid" >> - prepared for those planning trips to high altitudes.

-----

 For a detailed list of what to include in your expedition medical kit and step-by-step instructions for assembling your personal first aid set, see the ebook "High-Altitude Expedition Medical Kit Guide" >>

PLANNING A TREK OR A HIGH-ALTITUDE EXPEDITION?

If you would like to check whether your health condition allows you to safely participate in a trek or high-altitude expedition, consider booking a medical consultation >> or using a telemedical expedition package >>

This allows you to assess potential health risks in advance, prepare properly fot altitude, and increase your safety during the expedition.

The company was established in 2004. The goal of MedEverest is education in the field of mountain medicine and the dangers of high altitudes. I deal with all medical aspects of staying at high altitude. I organize medical support for trekking and high-altitude expeditions.

Specialist Medical Practice Medeverest Robert Szymczak based in Gdańsk (80-360), at ul. Bolesława Krzywoustego 19F, NIP: 5841943576, REGON: 220148318.

All rights reserved. Copying content and photos is prohibited. Information obligation before consenting to data processing.(see).

Also checkStore regulations >> Implementation: ColinMedia.eu >>