Effects of flying and jet lag on fertility pt 2.

In my previous post I described some research that indicates fertility may be effected by the disruption to the body clock as a result of travelling across time zones (or any other job that requires shift work).  There is one hormone that may be taken as a supplement to help overcome and regulate the problems our bodies face as we fly in to different time zones – melatonin.

Melatonin is not new to me.  Some of my US colleagues have told me about the use of Melatonin to help them overcome their jet lag quickly when they are in Europe.

Last year I landed in Germany with a terrible headache that had lasted more than two days, pain killers just didn’t touch it, and I couldn’t sleep – which was probably perpetuating my headache.  So my US colleague suggested I took some melatonin to help me sleep and kick start my body into a natural rhythm.  He warned me that melatonin can have side effects, such as vivid dreams.  I already dream a lot normally, and I had problems in Afghanistan with Anti-Malerial drugs causing vivid dreams and hallucinations; so I was very cautious of taking melatonin.  But I was willing to give it a try as by my third night in Germany I was consistently unable to fall asleep until about 5AM, then working all day with this awful headache.  So I took two of the little melatonin pills, and they helped me to fall asleep before midnight.  Bliss.  I did have some vivid dreams, actually they were more like nightmares, but at least I got some shut eye!  My headache didn’t disappear though, so I decided not to take any more melatonin. I was more afraid of my dreams than my headache.

I didn’t know much about melatonin at that time; I didn’t really look into it.  But since suffering from infertility I have been educated more into melatonin and its purpose.  I came across it in the book “It starts with the Egg” by Rebecca Fett, but I didn’t pay it much attention.

So what is melatonin?  It is a hormone that helps regulate many other hormones in the body and helps to maintain our body clocks (or circadian rhythms).  During light hours of the day, our natural melatonin production drops and when it is dark, the body produces more melatonin.  If we are not exposed to enough light during the day or too bright artificial light in the evening this can disrupt the body’s natural melatonin cycle.

What does melatonin have to do with fertility?  Melatonin is produced by the pineal gland in the brain, but it is also produced by the follicles within an ovary, the mass of cells that surround the follicles, and in the immature follicle itself.  It is here where melatonin acts as an antioxidant which supports cellular health and protection of the immature egg from oxidative stress, especially at the time of ovulation.  Melatonin has beneficial effects not just on eggs but also on embryos.  Mouse embryos grown in a lab with melatonin showed an increased rate of forming bastocyst-stage embryos [1].  As a result of this success, clinical trials were undertaken.   A study of 115 women showed that melatonin may increase egg quality by reducing the level of one oxidising agent called 8-0HdG in the ovum, which is a natural product of DNA oxidation [2].  Women who were given melatonin had a fertilisation rate much higher than their previous cycle and nearly 20% of the melatonin treated women became pregnant.  Whereas only 10% of the non-melatonin group became pregnant.

Melatonin also helps to control body temperature, the timing and release of female reproductive hormones and possibly egg quality.

Finally, melatonin is known to act as an antioxidant during early pregnancy.  In addition, melatonin in the mother’s blood passes through the placenta to aid the creation of the fetal suprachiasmatic nucleus (SCN) where the central circadian regulatory system is located.

Melatonin levels decline with age, and as a result the ovaries lose their natural protector against oxidative stress; hence could be an additional contributor to age-related infertility.

If you are going to consider taking melatonin as a supplement when trying to conceive you need to be careful and should ask your doctor, because the melatonin supplement may disrupt the natural hormone balance and interfere with ovulation.  If you are going through a controlled hormone cycle with IVF this is less of a concern.  In addition, melatonin can cause side effects, such as daytime droziness, dizziness, and irritability and may worsen depression.  Melatonin can also interact with other drugs, so this is why it is important to check with your doctor before taking it.

If you are going to take melatonin as a supplement whilst travelling it is also important to know what time to take it.  You should take the supplement after dark the day you travel and after dark for a few days after arriving at your destination.  In addition, taking melatonin in the evening a few days before you fly if flying eastward.  Again, there is caution to be made here because the long term effects of taking the supplement are unknown.  Therefore this is not overly helpful for airline attendants or shift workers, and only for those who travel infrequently.

For me, personally, I am undecided as to whether or not I will take melatonin as a supplement for either my next IVF cycle or when I am on my next international trip.  But I will certainly be asking my doctor next time we speak.

Have you taken melatonin as a supplement? What are your experiences with it?

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[1] The effect of melatonin on in vitro fertilization and embryo development in mice.  Available here: http://hera.ugr.es/doi/15015646.pdf

[2].  The role of melatonin as an antioxidant in the follicle.  Available here: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3296634/

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Effects of flying and jet lag on fertility pt 1.

I am just returning from yet another trip to Europe, Belgium this time!  This has been my 9th transatlantic trip this year.  Last year I made 10 trips, and the year before that 11.  With an average of a trip every 6-8 weeks I spend a lot of time either sat in a plane or at an airport or, trying not to fall asleep in meetings whilst I try to get over the jet lag!!

Travelling like this is stressful.  I always have a connection to make in the US because I do not live near an international airport, and sometimes I have another connection in Europe as I travel to cities that do not connect directly with the USA so I can often end up with 2 transfers…it can be very stressful making these connections when flights get delayed or security lines hold me up.  For example on this particular trip to Belgium, due to a series of unfortunate and unrelated disruptions it took me 9 hours longer to reach my destination (on top of the planned 14 hours of travel).

I am simply sick and tired of it.  Yes, I get to go visit some cool cities, I am grateful for that opportunity, but it is physically disruptive to my life.  As this is my last trip of the year and I already have 7 trips planned in the first 5 months of next year :-s I am beginning to wonder whether it is such a good idea to do all this travelling.  I am not sure how many of these I will be able to commit to with my next round of IVF coming up.

This got me thinking about how little I know about the effects of flying on my fertility.  Is it even an issue?  Should I be concerned?  So I did a bit of research and here is what I have found so far:

There is currently no overwhelmingly strong evidence that flying has a direct cause of reduced fertility.  However, there are a few studies that indicate that there may be some correlation.

One study I found to be compelling used mice to investigate whether shifting the body clock has an effect on their fertility [1].  The results of this study showed that there may be serious implications for a woman’s reproductive health if her work involves shift work or time zone changes.

To understand the outcome of this study, you need to understand the body clock.  Our body clocks are called circadian rhythms, these are physical, mental and beahvioural changes that follow a roughly 24 hour cycle, responding primarily to light and darkness in the environment.  Your circadian rhythm is produced by your body, but it is also influenced by the environment.  Light is the main thing that influences circadian rhythms – it turns on or off genes that control your internal clock.  Your circadian rhythm can change your sleep-wake cycles hormone release, body temperature and other important bodily functions [2].  (I know travelling certainly screws up my body temperature because I discovered this last year when we were trying to conceive the good old way and I was actually bothering to monitor my temps.)

The researchers of this study found evidence suggesting the severity of circadian disruption may be linked to the severity of pregnancy disruption: mice subjected to advances of the light-dark circle had greater circadian clock disruption and lower reproductive success.  This group’s pregnancy success rate was only 22% compared with the control group of 90%.

WOAH. That’s quite a difference!

So what does this mean?  This means that if this affects mice, there is a good chance it affects humans too – but to what extent remains unknown, more research is needed before conclusions can be made confidently. ….but I couldn’t find anything taking this research further forward.

Now, there have also been a large survey study of flight attendants to examine fertility….there are two interesting conclusions, first that flight crew were found to be more likely to suffer from irregular periods, and also more likely to suffer a miscarriage.  But I find the study designs less compelling, so I’m not even going to write about this in much detail (but you can judge for yourself here).

So is there something that can be done to prevent suffering from the effects of flying and jet lag?  No one knows for sure, but we do know that Melatonin is an important hormone that regulates other hormones…this can be taken as a supplement, but it can also have negative effects on fertility too when taken as a supplement.  And this is what I will talk about in some more detail in Part 2 later this weekend!

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Am I less fertile because I travel trans-Atlantic a lot?

[1]  Summa KC, Vitaterna MH, Turek FW (2012) Environmental Perturbation of the Circadian Clock Disrupts Pregnancy in the Mouse. PLoS ONE 7(5)

[2] Circadian rhythms fact sheet on the National Institute for General Medical Sciences website