Written by: Juliann Scholl
Updated March 26, 2021
Sleep plays an integral role in body function and overall health. This includes the regulation of hormones (1), which in turn control organ functions, growth, and reproduction. Small fluctuations in hormones can lead to large bodily changes. Although the relationship between sleep and conception in humans is still being researched, there are several compelling studies that point to a connection.
Can Sleep Affect Conception?
Circadian rhythms are biological patterns that follow a 24-hour cycle (2) and are strongly guided by exposure to light and dark. Most creatures, including plants, animals, and humans are governed and affected by circadian rhythms. While the most obvious circadian rhythm is the sleep-wake cycle, another major function of the body clock includes hormone secretion.
There is still little data linking circadian rhythms to human fertility. However, several research studies have connected the sleep-wake cycle and the internal 24-hour clock to important reproductive functions in animals. For example, researchers have found that female rats experience an afternoon surge (3) of ovulation-triggering hormones. When mice are subjected to disordered 24-hour sleep cycles, they experience reduced embryo implantation. Additionally, mice with a mutation in the gene that regulates circadian lengths and rhythms experience frequent embryo loss.
Some evidence also suggests that disrupted sleep may negatively affect ovulation in people. The majority of studies on humans and circadian effects on fertility focus on female shift workers, such as those in the medical field. Shift work, particularly night work, can lead to menstrual and ovulation disruption. In a study of over 400 nurses, those working nights more than seven times per month developed irregular menstrual cycles (4) that did not recover after a two-year follow-up phase.
Does the Amount of Sleep Affect Fertility?
The amount of sleep people get each night appears to matter for fertility. The follicle-stimulating hormone plays an important role in both the production of sperm and ovarian function. A study found that follicle-stimulating hormone levels were 20% higher (5) in long-time sleepers (those getting eight hours of sleep or more) than short-time sleepers (those getting less than eight hours of sleep).
Another study monitored the effects sleep duration had on in vitro fertilization outcomes (6). The researchers assigned participants to one of three categories: short-time sleepers (four to six hours), moderate-time sleepers (seven to eight hours), and long-time sleepers (nine to 11 hours). Fertilization rates were similar across the three groups, but pregnancy rates were around 7% higher in moderate sleepers compared to short sleepers and about 10% higher in moderate sleepers than long sleepers.
One of testosterone’s roles in fertility is balancing the desire to have sex. Low testosterone (7) leads to a low sex drive. The majority of testosterone release in men happens at night, and fragmented sleep can result in lower levels. A study found that daily testosterone dropped by 10% to 15% (8) after a week of sleep being restricted to five hours per night.
How Can I Improve my Sleep to Help With Conception?
The available evidence suggests that sleep may be a factor in conception. Practicing good sleep hygiene is an effective way (9) to ensure regular, restful nights. Sleep hygiene refers to the physical environment and lifestyle behaviors surrounding sleep. Try the following tips to strengthen your sleep hygiene:
- Avoid caffeine, alcohol, and nicotine before bedtime.
- Get regular exercise, but not too close to bedtime.
- Expose yourself to daylight as often as possible.
- Find ways to reduce stress before sleep, such as through mindfulness or meditation.
- Reduce noise disruptions in the sleep environment.
- Avoid backlit electronics that emit blue light prior to bedtime.
- Minimize light in the bedroom.
- Stick to regular sleep and wake times.
Taking steps to improve sleep hygiene is good for mental and physical health, and can help support a healthy endocrine system to promote fertility.
- https://medlineplus.gov/healthysleep.html Accessed on March 21, 2021.
- https://www.nigms.nih.gov/education/fact-sheets/Pages/circadian-rhythms.aspx Accessed on March 21, 2021.
- https://link.springer.com/article/10.1007%2Fs40675-016-0057-9 Accessed on March 21, 2021.
- https://pubmed.ncbi.nlm.nih.gov/27145834/ Accessed on March 21, 2021.
- https://pubmed.ncbi.nlm.nih.gov/11937126/ Accessed on March 21, 2021.
- https://www.fertstert.org/article/S0015-0282(13)01207-7/fulltext Accessed on March 21, 2021.
- https://pubmed.ncbi.nlm.nih.gov/28816715/ Accessed on March 26, 2021.
- https://pubmed.ncbi.nlm.nih.gov/21632481/ Accessed on March 21, 2021.
- https://pubmed.ncbi.nlm.nih.gov/25454674/ Accessed on March 21, 2021.