As the holiday season kicks into full swing, you may be one of the millions of people taking a flight. In fact, more than 6.4 million people travelled by air between December 12, 2017 and January 1, 2018, with projections only increasing for this year (CNN, 2017). Whether you are connecting with family, visiting home, or taking a well-deserved vacation, you may be wondering if air travel will affect your fertility. There are many physiological changes associated with travel that have the potential to disrupt internal processes, such as an altered sleep cycle, stress, shift in time zone, and change in diet. Researching how these factors relate to fertility can be tedious and confusing, especially given the lack of open discourse surrounding women’s reproductive health. Below are scientific answers to some questions women may have regarding fertility and plane travel.
Can plane travel affect cycle timing and fertility?
Though plane travel itself doesn’t alter cycle timing, some of the consequences of plane travel can. Travel significantly alters one’s routine, especially if it is across time zones. A woman’s monthly cycle is intricately connected to her circadian rhythm, and external factors such as food, shifted light/dark phases, and stress can have major effects. During different parts of the day, the body expresses certain genes, named clock genes, at different concentrations. These genes are in control of hormones in the body, such as melatonin, that can induce sleep and wakefulness (Ono, Honma & Honma, 2005). Irregular meal timing during travel can interfere with this internal clock. In fact, one study showed that delaying meal times by 5 hours produced such dramatic results in clock gene expression, that researchers suspected food timing plays a critical role in synchronizing circadian rhythm (Wehrens, et al., 2017). Stress has been revealed to modify the internal rhythm as well. Cortisol, which is regarded as a stress hormone, has been shown to have its own circadian rhythm, with effects ranging from sleep to digestion (Chan & Debono, 2010). Stress, sexual hormones, and sleep hormones seem to have an interconnected relationship. When one is altered, the impacts can have a rippling effect through the body. A journal article published in 2016 reviewed numerous studies in the fertility and circadian rhythm field and found evidence that the pre-ovulation Luteinizing Hormone has a circadian rhythm much like clock genes and cortisol. Current evidence supports that prolonged sleep disruption and psychological disturbance may result in ovulatory problems (Wolfson & Sharkey). Women who travel for their jobs, such as flight attendants, have been shown to have higher rates of reproductive illnesses and irregular menstrual cycles. The exact cause of this is unknown, though it is most likely a combination of chemicals in the environment and consistent disruption to their circadian rhythms (Ballard, et al., 2006).
So, the bottom line is that plane travel can certainly alter a woman’s monthly cycle, due to the change in sleep cycle and other factors. However, the negative effects of travel are short-lived, and if plane travel is not a frequent occurrence, there is minimal risk to fertility. Women in occupations that require constant travel are more vulnerable to negative consequences of plane travel, but traveling for a holiday vacation will not have much impact.
What are ways to minimize the stress of travel on the mind and body?
Planning out a trip in advance and minimizing the hassle of air travel could be beneficial. Ways to do this are leaving to the airport early, wearing comfortable clothing, and paying attention to the things that help you remain calm during travel. Though some disruption to your cycle is inevitable, maintaining good nutrition and eating frequently enough is good practice. Most people do not travel enough to continuously alter their circadian rhythms, and the body of research still is not conclusive. If you travel by air frequently, conversing with your doctor may be useful.