In part 1 of the fertility series, we considered individual nutrients to support the health of egg and sperm cells. In part 2, we delve into lifestyle recommendations to further support couples when trying to conceive. 

Tracking your menstrual cycle is an inexpensive (and often free) way of gaining a better understanding of your menstrual health, provided you are not taking an oral contraceptive pill or have an IUD. Not only does this increased awareness give you indications about your average cycle length, but, if you are regular, it also indicates ovulation and your fertility window. However, menstruation does not always mean ovulation has occurred. To gain more accuracy, consider also tracking your basal body temperate and cervical mucus.

Basal body temperature refers to your rested body temperature and is best recorded on waking before getting out of bed. It is common for a woman’s basal body temperature to be at its lowest one day prior to ovulation, with an increase in basal body temperature suggestion ovulation has occurred. (1) 

Similarly, self-observation of mucus at the vulva can help to identify ovulation, with the presence of mucus indicating the start of the fertility window. (1) The end of the fertility window is roughly a few days after the last day the mucus appears to be fluid. A study monitoring ‘peak mucus’ yielded 96% sensitivity in identifying at least one day in a 6-day fertility window by recording mucus alone. (2) 

While apps may provide useful tips, please follow their advice with caution. Studies suggest they are not accurate and should only be used to provide a better understanding of your body. (3) Individual differences exist in cycle lengths and fertility windows. 

Studies suggest that a BMI over 35 can reduce sperm count in men. (4) In women, obesity is linked to reproductive dysfunction via several mechanisms. Firstly, adipose tissue produces a hormone called leptin. Better known for inhibiting hunger, leptin can also act on ovarian cells and interfere with ovulation. (5) Obesity also increases the body’s circulating levels of androgens and the enzyme aromatase, which converts testosterone to oestrogen. Excess weight is also associated with a reduction in sex hormone-binding globulin (SHBG), a protein that binds androgens and oestrogens. A reduction in SHBG therefore leads to an increase in androgens and oestrogens, which may reduce the occurrence of ovulation. (5)

High insulin levels, a result of blood sugar spikes, and subsequent insulin resistance when the cells become unresponsive to the action of insulin, contribute to weight gain and the production of androgens. Rich in polyphenols and fibre, the Mediterranean-type diet, as discussed in part 1 of the fertility series, may improve insulin sensitivity. (6) In overweight individuals, weight loss may further decrease androgen levels, improve the body’s sensitivity to insulin, and restore ovulation, with a healthy BMI improving fertility outcomes. (4, 7, 8) 

Exercise is important for maintaining a healthy weight and increasing insulin sensitivity. (9) However, some research has found that men who cycle for more than 5 hours per week may have reduced sperm count and motility (because of increased temperature and potential trauma in the scrotum/groin area), meaning this specific form of exercise should be modified when addressing fertility. (4)

In women, exhaustive exercise may increase the risk of infertility. (4) Thus, if you partake in competitive sport and have an irregular menstrual cycle, consider switching to a less vigorous form of exercise. 

However, for overweight women with PCOS, exercise has been shown to improve fertility outcomes. (10) 

Endocrine-disrupting chemicals (EDCs) can negatively affect the body’s hormonal system in both men and women. In women, exposure to pesticides, heavy metals, plasticisers, such as BPA, PCBs and parabens, is linked to reduced fertility and sex hormone production. (11) In men, exposure to EDCs may reduce sperm count. (12)

Here are a few ways to reduce your exposure: 

• Consider purchasing glass containers to store food rather than using plastic storage containers 
  
• Consider a glass bottle rather than a plastic bottle to transport drinks in 
  
• Check the ingredients label on your beauty products for ingredients containing the suffix paraben. Replace products containing paraben ingredients with paraben-free alternatives 
  
• Be sure to thoroughly wash non-organic fruit and vegetables, opting for organic where possible 
  
• Consider a water filter when drinking tap water 
  
• Consider going paperless when requesting a receipt – these often contain BPA. Many retailers will now email you a copy rather than print it on paper 
  
• Consider replacing household cleaning products and gardening sprays with natural alternatives now widely available in many supermarkets 
  
• Limit fish intake to once a week, especially freshwater fish such as salmon, catfish and trout 

In part 1 of the fertility series, we discussed the importance of antioxidants in protecting against reactive oxidative species (ROS). In women, increased ROS production is harmful to the development of egg cells. In men, when antioxidant defences are outweighed by ROS production, DNA damage may occur alongside reduced sperm motility. (13) The diet can be one source of increased ROS production but modifiable lifestyle factors also contribute:

Smoking - A source of ROS and EDCs, smoking is linked to negative fertility outcomes for both men and women. In men, smoking negatively affects sperm motility. (14) Cessation, on the other hand, improves fertility, as well as stress parameters, another source of ROS. (4, 15) 

Alcohol consumption - Although low alcohol consumption (less than 4 drinks per week) may not negatively affect fertility in women, moderate to high alcohol consumption could decrease the likelihood of conception. (4) 

Caffeine - High consumption (>500mg/day) may increase the time it takes to get pregnant. (4) 

Stress - While avoiding stress is not always a viable option, developing healthy coping strategies may help to better support the body in dealing with stressful situations. In a study, therapies such as cognitive behavioural therapy, relaxation and social support all increased pregnancy rates for women undergoing their second cycle of IVF. (4) 

Heat exposure - In men, increased scrotal temperature may reduce sperm quality. One study suggested that more than 30 minutes per week of hot water exposure from a hot bath, jacuzzi or hot tub may reduce sperm quality. Other studies suggest that tight-fitting underwear also has negative effects. Sperm quality can be improved by modifying these lifestyle factors. (17) 

Mobile phone - Through the production of ROS and increased body temperature from mobile phone use, exposure is negatively linked with sperm quality in men. (16) Consider carrying your mobile phone in a bag rather than a trouser pocket. 

Dietary and lifestyle factors play an important role in supporting the health of egg and sperm cells, reducing risk factors for infertility. Making modifiable changes in these areas is non-invasive and a reasonably inexpensive way of nurturing egg and sperm cells to support fertility. A study following over 17,000 women over an 8 year period found that modifying multiple lifestyle factors, such as diet, weight and physical activity, correlated with a 69% lower risk for ovulatory disorders. (19)

Despite the capacity for improvement such changes may bring to fertility issues, for those of you with a medical condition affecting fertility, or who have been unsuccessful in achieving pregnancy for a prolonged period of time, seek support from a qualified healthcare practitioner. They can investigate further with functional testing and give tailored advice based on your individual results. 

1. Symul, L., Wac, K., Hillard, P., & Salathé, M. (2019). Assessment of menstrual health status and evolution through mobile apps for fertility awareness. NPJ digital medicine, 2, 64. doi:10.1038/s41746-019-0139-4 
   
2. Ecochard R, Duterque O, Leiva R, Bouchard T, Vigil P. Self-identification of the clinical fertile window and the ovulation period. Fertil Steril. 2015;103:1319.e3–1325.e3. 
   
3. Starling, M. S., Kandel, Z., Haile, L., & Simmons, R. G. (2018). User profile and preferences in fertility apps for preventing pregnancy: an exploratory pilot study. mHealth, 4, 21. doi:10.21037/mhealth.2018.06.02 
   
4. Collins, G.G., Rossi, B.V. The impact of lifestyle modifications, diet, and vitamin supplementation on natural fertility. Fertil Res and Pract 1, 11 (2015) doi:10.1186/s40738-015-0003-4 
   
5. Gambineri, A., Laudisio, D., Marocco, C., Radellini, S., Colao, A., & Savastano, S. Obesity Programs of nutrition, Education, Research and Assessment (OPERA) group (2019). Female infertility: which role for obesity?. International journal of obesity supplements, 9(1), 65–72. doi:10.1038/s41367-019-0009-1 
   
6. Guasch-Ferré, M., Merino, J., Sun, Q., Fitó, M., & Salas-Salvadó, J. (2017). Dietary Polyphenols, Mediterranean Diet, Prediabetes, and Type 2 Diabetes: A Narrative Review of the Evidence. Oxidative medicine and cellular longevity, 2017, 6723931. doi:10.1155/2017/6723931 
   
7. Dağ, Z. Ö., & Dilbaz, B. (2015). Impact of obesity on infertility in women. Journal of the Turkish German Gynecological Association, 16(2), 111–117. doi:10.5152/jtgga.2015.15232 
   
8. Silvestris, E., de Pergola, G., Rosania, R. et al. Obesity as disruptor of the female fertility. Reprod Biol Endocrinol 16, 22 (2018) doi:10.1186/s12958-018-0336-z 
   
9. Mann S, Beedie C, Balducci S, et al. Changes in insulin sensitivity in response to different modalities of exercise: a review of the evidence. Diabetes/metabolism Research and Reviews. 2014 May;30(4):257-268. DOI: 10.1002/dmrr.2488. 
   
10. Cheryce L. Harrison, Catherine B. Lombard, Lisa J. Moran, Helena J. Teede, Exercise therapy in polycystic ovary syndrome: a systematic review, Human Reproduction Update, Volume 17, Issue 2, March-April 2011, Pages 171–183, https://doi.org/10.1093/humupd/dmq045 
    
11. Rattan, S., Zhou, C., Chiang, C., Mahalingam, S., Brehm, E., & Flaws, J. A. (2017). Exposure to endocrine disruptors during adulthood: consequences for female fertility. The Journal of endocrinology, 233(3), R109–R129. doi:10.1530/JOE-17-0023 
    
12. Mendiola, Jaime & Torres-cantero, Alberto & Agarwal, Ashok. (2009). Lifestyle factors and male infertility: an evidence-based review. Archives of Medical Science. 5. S3-S12. 
13. Firns, S., Cruzat, V.F., Keane, K.N. et al. The effect of cigarette smoking, alcohol consumption and fruit and vegetable consumption on IVF outcomes: a review and presentation of original data. Reprod Biol Endocrinol 13, 134 (2015) doi:10.1186/s12958-015-0133-x 
14. Harlev A, Agarwal A, Gunes SO, Shetty A, du Plessis SS. Smoking and Male Infertility: An Evidence-Based Review. World J Mens Health. 2015 Dec;33(3):143-160. https://doi.org/10.5534/wjmh.2015.33.3.143 
15. Taylor Gemma, McNeill Ann, Girling Alan, Farley Amanda, Lindson-Hawley Nicola, Aveyard Paul et al. Change in mental health after smoking cessation: systematic review and meta-analysis BMJ 2014; 348 :g1151 
16. Adams, J. A, Galloway, T. S, Mondal, D., Esteves, S. C, & Mathews, F. (2014). Effect of mobile telephones on sperm quality: A systematic review and meta-analysis. Environment international, 70, 106-112. doi: 10.1016/j.envint.2014.04.015 
17. Sharma, R., Biedenharn, K.R., Fedor, J.M. et al. Lifestyle factors and reproductive health: taking control of your fertility. Reprod Biol Endocrinol 11, 66 (2013) doi:10.1186/1477-7827-11-66 
18. Goldstein, C.A. & Smith, Y.R. Curr Sleep Medicine Rep (2016) 2: 206. https://doi.org/10.1007/s40675-016-0057-9 
    
19.  Chavarro JE, Rich-Edwards JW, Rosner BA, et al. Diet and lifestyle in the prevention of ovulatory disorder infertility. Obstet Gynecol. 2007;110(5):1050–1058. doi: 10.1097/01.AOG.0000287293.25465.e1