Oh, by the way...Can I ski while Im pregnant?

Michelle, a 31-year-old G1P0, is in for a routine second-trimester prenatal visit at 18 weeks. During the visit, she mentions that her family is gearing up for their winter vacation. As you are walking out the door, she says, "Oh, by the way... can I ski?"

Exercise is not off limits during uncomplicated pregnancies. The Centers for Disease Control and Prevention and American College of Sports Medicine recommend 30 minutes of moderate exercise each day in pregnancy. The American College of Obstetricians and Gynecologists says that women accustomed to exercise may continue to do so in pregnancy, but cautions against starting a new program or intensifying exertional efforts.¹ Excessive fatigue risks injury to both mother and fetus. Aerobic activities, such as dancing, swimming, water aerobics, yoga, Pilates, walking, strength and flexibility training, and stationary biking are excellent ways to keep fit and active in pregnancy.

Even joggers and distance runners can continue their established regimens in pregnancy. Physically fit women who run have been shown to have a shorter active phase of labor, lower C/S rates, less meconium-stained amniotic fluid, and fewer non-reassuring fetal heart rate patterns. Running has not been associated with increased miscarriage rates but has been associated with a modest reduction in birthweight.²

The risks associated with skiing during pregnancy include falling and injury. The safety of any activity rests on the movements involved. Skiing and other activities, such as horseback riding, gymnastics, and ice-skating, are associated with an increased risk of falling and associated trauma to both mother and baby.¹ Musculoskeletal and certain other physiologic changes associated with pregnancy, such as a shift in the center of gravity and increased joint mobility, amplify the concern.

During pregnancy, a woman's center of gravity shifts back over her lower extremities to compensate for the enlarging uterus. Her posture is altered due to the increased mobility of the sacroiliac, sacrococcygeal, and pubic joints. These changes can affect her balance and increase the risk of falling. Decreased exercise tolerance and the increased physiologic and metabolic demands of pregnancy can lead to fatigue, especially at high altitudes. Most skiing experts agree that fatigue is a variable that increases the risk of falling. Falls account for approximately 75% of ski injuries, but are not the only dangers on the slopes. Collisions and lift accidents, especially with the varying degrees of expertise on the slopes, can magnify the dangers.

Trauma to the gravid abdomen can be catastrophic, given the engorged pelvic and abdominal vasculature in the gravid abdomen and the shearing forces associated with starting, turning, and stopping while skiing. Traumatic placental abruption, uterine rupture, fetal-maternal hemorrhage, and even direct fetal injury can complicate a fall or collision while skiing. The appropriate management for a pregnant woman who sustains a fall is at least 6 to 24 hours of fetal monitoring.³

The impact of altitude

An additional concern is altitude. Although exertion at altitudes up to 6,000 feet appears safe in pregnancy, exertion beyond that point risks fetal hypoxia, preterm labor, and altitude-related conditions such as acute mountain sickness (AMS), high-altitude pulmonary edema (HAPE), and/or high-altitude cerebral edema (HACE). These acute syndromes have been described as low as 8,000 feet but are more likely at altitudes greater than 10,000 feet. And they are not rare. AMS occurs in 42% of people exposed to altitudes higher than 10,000 feet. AMS presents first but may progress to the more severe conditions of HAPE and HACE.

Prior ascents without symptoms do not guarantee that future climbs will be safe and there is no correlation between severity and higher altitudes. Acclimatization by slow ascent is the best prevention, but descent to a lower altitude is the treatment. Pregnancy itself is not associated with abnormal acclimatization, but it may predispose to a longer period of adjustment.

Even the fittest pregnant women may lack the endurance and agility to exercise at altitude because of the increased metabolic demands. They may also be more susceptible to AMS and more likely to progress to HAPE and HACE. To get the most out of a limited winter vacation, some individuals may overdo the exercise, predisposing themselves to the acute syndromes. Risk factors include exertion, age less than 50 years, and a higher level of aerobic fitness that can allow an individual to push further and ignore warning signs like headache, nausea, weakness, and dyspnea.⁴