Do Frequent Night Shifts Mess with Your Fertility Clock?

BySamradni Pradhan
Updated: 30 Jun 2025, 10:02 am

When you work night shifts and are trying to have a baby, you might be interested in knowing how your working pattern might be impacting your fertility. This blog helps you grasp how night shifts affect your natural body clock and reproductive health. You will learn how inconsistent schedules impact hormones, ovulation, and fertility, and how you can protect your chances of success in conceiving.

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Have you ever thought that your pregnancy plans could conflict with your night shifts? Well, then, you are not the only one. Most workers on odd or night jobs will be concerned about the effects of such routines on their bodies, particularly on their fertility.

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Of course, you know how important sleep is for your health. But have you ever considered that going against your body’s natural rhythm, by sleeping more at night when your body wants to be awake, or during the day when it wants to rest, can disrupt key bodily processes that affect your chances of conceiving?

We are going to take a closer look at how frequent night shifts may affect your reproductive health and what science knows about the relationship, as well as how you can take action to preserve your fertility in case you are not able to avoid working overnight.


Understanding Your Body's Internal Clock

Your body has a built-in timing system known as the circadian rhythm. This rhythm tells your body when to wake up, eat, sleep, and perform other functions. It operates on a 24-hour cycle and is closely tied to the cycles of light and darkness.

When you’re exposed to light during the day and darkness at night, your body knows when it’s time to rest and when it’s time to be active. But when you work night shifts, this natural rhythm can get confused. You may find yourself sleeping during the day, eating at odd hours, and feeling tired even after rest.

This confusion doesn’t just make you feel sleepy or off balance; it can affect your hormones, including the ones that control ovulation and fertility.


How Night Shifts Affect Your Fertility Hormones?

Hormones need to flow smoothly to your reproductive system. These hormones include melatonin, cortisol, luteinising hormone (LH), and follicle-stimulating hormone (FSH), which are involved in your menstrual cycle and the possibility of getting pregnant.

Here’s how night shifts interfere:

  1. Melatonin disruption

Melatonin is a hormone produced by your body during nighttime to assist you in sleeping. It also guards against the degradation of your eggs. Melatonin levels reduce when you are still awake at night due to exposure to light. This may cause improper quality of eggs or influence the atmosphere within your ovaries and uterus.

  1. Irregular Menstrual Cycles

Irregular periods are common among night shift workers. This may be a result of hormonal changes. When your cycle is irregular, it becomes more difficult to predict when you are ovulating, making it more challenging to conceive.

  1. Reduced Ovulation

Researchers have discovered that women working shifts (night hours and rotating hours) are more likely to be anovulatory; that is, they fail to produce an egg during their cycle. Without an egg, there is no opportunity for fertilisation.

  1. Increased Cortisol

When you work at night and sleep during the day, you are likely to experience poor sleep quality. This increases cortisol as a stress hormone. Chronic elevated cortisol may disrupt the reproductive hormones, decrease the libido, and influence fertility.


Shift Work and Polycystic Ovary Syndrome (PCOS)

If you already have PCOS, working night shifts may make it worse. PCOS is a hormonal condition that affects ovulation. People with PCOS are already dealing with hormone imbalances, and adding sleep disruption and stress from night work can further affect their cycles and fertility.

Some research suggests that a lack of sleep and irregular routines can raise insulin levels, which is also linked to PCOS symptoms like irregular periods and difficulty ovulating.



Impact on Male Fertility

If your partner also works night shifts, it’s important to know that male fertility can also be affected. Sleep deprivation and circadian disruption can lower testosterone levels, reduce sperm quality, and increase DNA damage in sperm. So, it’s not just your routine that matters; your partner’s habits play a role too.


Night Shifts and Pregnancy Risks

Even after you conceive, frequent night shifts may carry risks for pregnancy. Some studies show that night shift workers are at a slightly higher risk of complications like:

  • Miscarriage
  • Preterm birth
  • Gestational hypertension (high blood pressure)
  • Low birth weight
The exact reasons aren’t always clear, but poor sleep, hormone imbalances, and stress are likely to contribute.


Can You Reduce the Impact?

If you work night shifts and are trying to get pregnant, don’t panic. You don’t necessarily have to quit your job, but you can make changes to protect your fertility and support your body. Here’s what you can do:

  1. Prioritise sleep hygiene: Even if you sleep during the day, make sure your room is dark, quiet, and cool. Use blackout curtains and turn off screens an hour before bedtime.
  2. Stick to a schedule: Try to keep your sleep and meal times as consistent as possible, even on your days off. This helps your body adjust to a predictable pattern.
  3. Limit caffeine and stimulants: Avoid heavy caffeine use or energy drinks during your shift, especially near the end. These can make it harder to sleep and may raise your stress levels.
  4. Protect yourself from light exposure: Wear sunglasses on your way home after a night shift. This signals to your body that it’s time to prepare for sleep and stimulates melatonin production.
  5. Eat balanced meals: Shift work can lead to unhealthy eating. Choose nutrient-rich meals, stay hydrated, and avoid eating large meals close to bedtime.
  6. Get regular checkups: Visit your doctor or gynaecologist for regular hormone tests, especially if your periods become irregular or you’ve been trying to conceive for a while without success.

Your body relies on a natural rhythm to keep everything, from digestion to hormones, working smoothly. When you consistently work night shifts, that rhythm gets disrupted. Over time, this can affect your fertility by interfering with your menstrual cycle, hormone balance, and ovulation.

The good news is that you don’t have to give up on your fertility goals. By understanding the connection between your schedule and reproductive health, you can take proactive steps to protect your chances of conception, even if you’re working nights. Remember, your healthcare provider is your best partner on this journey.

FAQs on Do Frequent Night Shifts Mess with Your Fertility Clock?

  1. Can night shifts cause permanent infertility?
    Night shifts may affect your fertility by disrupting hormones and ovulation, but they don’t usually cause permanent infertility. With proper management and lifestyle changes, many people working night shifts are still able to conceive.
  2. How long should I wait before seeking help if I work night shifts and can't conceive?
    If you’re under 35 and have been trying for more than a year or over 35 and trying for six months, it’s a good idea to consult a fertility specialist, especially if your cycles are irregular.
  3. Is it harder to get pregnant through IVF if I work night shifts?
    Some research suggests that sleep disruption and circadian imbalance can affect IVF success rates. If you're planning fertility treatments, talk to your doctor about ways to improve sleep and hormone balance.
Disclaimer: Medically approved by Dr Pallavi Prasad, Fertility Specialist, Nova IVF Fertility, Basaveshwarnagar, Bangalore.