Traveling comes with a whole host of baggage, both literal and physical. For women, there is the added burden of a reproductive system and monthly cycle that are particularly sensitive to the types of curveballs—stress, time zone shifts, lack of sleep, changes in diet and routine—that are synonymous with long-haul or frequent travel.
Unsurprisingly, actual information about how to deal with these disruptions with your menstrual cycle, fertility, and sanity in tact is scant. Despite the fact that women have menstruated and ovulated since time immemorial—and gotten their periods on planes, trains, automobiles, camelbacks, wagons and every other inconvenient location you can think of—the entire process is still shrouded in a degree of mystery. Not to fear, though—Quartzy has you covered. We asked the experts and frequentest fliers to provide a complete guide of traveling with a uterus, from periods and the pill to cycle-tracking and fertility.
Contrary to some myth-making, actually being on an airplane isn’t likely to cause your period to come early—or not show up at all. Though getting your period unplanned mid-flight can range from an inconvenience to a minor disaster, it is probably just an annoying coincidence (hot tip: ask cabin crew if you’re really desperate for supplies).
Dr Anita Mitra is an NHS gynecologist and evidence-based blogger who completed her PhD on the vaginal microbiome, or the collection of healthy bacteria inside the vagina. She says it’s not the flying that’s the problem, but the act of travel itself. Whether you’re crossing multiple datelines or just getting up super early to catch a train to the next county, travel messes with your routine. This is important because it has a significant impact on the two primary hormones that affect women’s monthly cycles: melatonin and cortisol.
“Even subtle changes to your daily pattern—getting up super early one day and then sleeping late the next—can have a small effect on your melatonin levels,” Mitra says. “So it’s less the flight, and more that the flight has taken you to another destination and time zone.”
When it comes to stress, sitting in traffic en route to the airport or sprinting to your departure gate can certainly spike your cortisol levels. But even subtler, low-level stress—like sleeping in a bed that’s not yours or wondering how your cat is at home—can upset your body’s equilibrium.
“There is an evolutionary basis for why this kind of stress affects our cycles,” Mitra said. “If you’re in ‘fight or flight’ mode, your body doesn’t know whether it has the energy to waste on having a period. We don’t fully understand the brain-uterus connection, but we know that the brain is the first link in the hormonal chain that produces a menstrual cycle.”
When our cortisol and melatonin levels fluctuate, so too does the window in which we are fertile, which generally lasts for 6 days of a 28 day cycle. This shift in when we ovulate then causes our periods to come early, late, or not at all. Leena Chung, a flight attendant for Emirates who is based in Dubai, says the toll that flying takes on the female body is a frequent topic of galley conversation among cabin crew: “Flying has actually messed up my whole menstrual cycle. The effect of it was more apparent when I was operating ultra long haul flights with a completely different time zone (e.g Dubai to Los Angeles). Coupled with jet lag, fatigue and long flying hours in a month, sometimes my period would be days late or a month late.”
So what can be done about this? Not a lot. Just know that disruption to your cycle is normal if you’re traveling a lot or, for that matter, are going through a particularly chaotic time in your life. So a late period shouldn’t cause undue stress. (Tracking your cycle and/or use natural family planning as a form of birth control is addressed in a section below.)
If you’re on hormonal contraception, it’s more likely that your period will arrive on time when you travel—because it is artificially triggered each month when you stop ingesting hormones for seven days, rather than triggered by your body’s cycle. Though Mitra notes pill takers may find their periods are lighter or heavier than usual for the same hormonal fluctuations described above. Those who use the coil, IUD, other non-hormonal forms of contraception, though, shouldn’t be surprised by variability in their periods when traveling.
Pill-takers have a bit of work to do when it comes to ensuring they are taking their pill regularly and avoiding a risky time gap when crossing time zones. There are generally two types of pills: the combined estrogen-progestin pill (which contains 21 days of active pills, with a seven day break or seven day placebo pill) and the progestin-only pill (which requires 28 consecutive days of pill taking, with varying degrees of hormones in each pill). The latter, Mitra says, is less forgiving when it comes to late pills, so you should never push it more than 12 hours after your usual pill time. The former is more forgiving, but if 24 or more hours have elapsed since your usual pill time (i.e. you took your pill on Tuesday at 3pm and it’s now Thursday at 3pm, meaning you missed Wednesday’s pill) Mitra says you should use a condom for seven days. However, some guidance (such as the NHS’s) is more lenient about a missed pill. To be sure, it’s best to refer to the instructions that come with your pill packet.
The best way to be safe in both cases is to pick a new time that works in both time zones. Let’s say you normally take your pill at 7pm in Los Angeles. Figure out what time that is at your destination (for example, London, so 3am). It clearly won’t be convenient to take your pill at 3am each day when you’ve switched time zones, so opt for an earlier pill time, rather than waiting for the usual time slot. In this case you might take your pill on the day of departure (Wednesday) at noon in Los Angeles. Then, on your day of arrival in London (Thursday), switch to taking it at 8pm in your new time zone (which is the same as taking it at noon in LA). When you return to Los Angeles, stay on the noon pill-taking time until you start a new pack after your period, when you can return to your regular time if you wish.
Be particularly careful on travel days. It can be hard to tell what time it is, especially if you have layovers in different time zones en route to your eventual destination. The best practice is to not think in linear days of the weeks—because you could be skipping entire days of the week if, say, you’re flying from LA to Asia—but rather, the number of hours elapsed since last pill. If needed, do the math before take off and set yourself an alarm for mid-flight.
Another thing pill takers need to be mindful of? Blood clots. Flying dehydrates you. Combine that with the lack of walking around on a long haul flight, and people who take the combined pill are at a higher risk of potentially lethal blood clots (though the risk is small). The solution? Drink water, don’t drink too much alcohol, and walk around as much as possible during your flight. For super long-haul flights, Mitra says compression socks aren’t a bad idea, either.
Lastly, as vomiting and diarrhea are more likely to happen to you while traveling, know that if either occurs within two hours of taking your pill, Mitra says you should treat it as a missed pill, and use alternative contraception, such as a condom, for the next seven days.
Thanks to apps like Clue and Natural Cycles, more and more women are getting to know their bodies through the practice of tracking their cycles. Whether you’re doing this for natural family planning—or simply to learn more about your body—it’s important to know that there are a lot of variables involved. And, as explained above, variability is the enemy of a predictable cycle.
According to a blog written by Clue, when you’re traveling it’s important to adjust your expectations of the app’s accuracy: “Be aware that your ovulation is likely to be off. If you are using a fertility awareness method (tracking basal temperature, cervical fluid, cervical position) to become or avoid becoming pregnant, expect your fertile days to be different from your Clue average.”
Mitra cautions that natural family planning involves a lot of variability, and that adding travel to the mix adds another big variable—one that apps may not be equipped to deal with. Because of that, she says, “you have to be a lot more open minded about using condoms” when you’re traveling and cycle-tracking for birth control.
The extent to which frequent flying has an effect on fertility is gaining more recognition thanks to the plight of flight attendants—many of whom have shared their struggle to conceive. Studies have explored the effect that exposure to radiation, flame retardants, and other occupational hazards have on flight attendant health, including fertility. Others have pointed out that flight attendants are far more likely to miscarriage than women in other professions.
Heather Poole, a veteran flight attendant and the New York Times bestselling author of Cruising Altitude: Tales of Crashpads, Crew Drama and Crazy Passengers, says it’s a problem she’s dealt with personally: “I spent a lot of time trying to get pregnant and doing everything I could to make sure I became pregnant and stayed pregnant. The best thing to do is fly less,” Poole said. “At one point I saw a fertility specialist who wanted to see me on specific days of my cycle, which wasn’t always easy to make happen—to get the day off.” Poole adds she worries about the health of younger flight attendants who are spending more and more time in the air early in their careers.
If you’re not a flight attendant—but are a very frequent flier who is trying to get pregnant—it is worth talking to a doctor or specialist about the fertility implications of spending lots of time in the air.
Update: This story has been updated to clarify that some guidance around how to handle a missed pill is more lenient than originally stated.