Everything you need to know about progesterone

Tamara HunterBlog

low progesterone

Low progesterone

Progesterone is a steroid hormone and it is produced in our body. A lot of women wonder if they can boost their low progesterone levels by eating certain foods that positively impact their chances of getting and staying pregnant.

How to increase progesterone?

Can I boost my progesterone levels?

Can I boost my progesterone levels by changing my diet? It’s a question that Stefanie Valakas, an accredited practising dietitian known from The Dietologist, gets time and time again. In episode 78 of her incredibly popular Fertility Friendly Food podcast, Stefanie interviews me about all things progesterone, including the elephant in the room: Can I boost my progesterone levels through dietary changes?

Unfortunately, and spoiler-alert, you cannot improve your fertility by eating progesterone-rich foods. That’s because progesterone is a steroid hormone and it is produced inside your body. However, some believe that certain foods, predominantly those containing vitamin B6 and zinc, can help the body produce more progesterone. Unfortunately, there is little evidence to support these theories.

Luckily, there are certain lifestyle changes that do have an impact on your menstrual cycle and your progesterone levels:

  • Sleep is vitally important to maintain a normal ovulatory cycle.
  • Excessive stress can elevate your levels of stress hormones, which can affect the ovaries and sex hormones. This is why some women may miss a period when they have high-stress levels.
  • Moderating your weight, both over- and underweight.

So let’s dive into the progesterone topic a little bit deeper. For those of you interested in the entire episode, please go to The Dietologist or find the episode on Spotify.

low progesterone

The different roles of progesterone explained

Progesterone belongs to a group of steroid hormones called ‘progestogens’.
“It has its own independent activities, predominantly in the uterus but also in the brain and in the adrenal glands. When you are pregnant, your placenta takes over and produces progesterone.”
Dr Tamara Hunter, Fertility Specialist Perth

Progesterone in your menstrual cycle

So here’s what happens in a normal cycle: Every single month, a female produces a group of follicles that are released from the storage. One of these follicles will be recruited as the dominant follicle and will ovulate. After ovulation, it switches to the corpus luteum, and it’s the corpus luteum that produces progesterone.
“That’s when it peaks, and it stays for the life of the corpus luteum, which is 2 weeks after ovulation. When the corpus luteum dies off, the progesterone levels drop and that leads to the lining of the uterus being shed.”
Dr Tamara Hunter, Fertility Specialist Perth
However, when the egg is fertilised, progesterone stimulates the growth of blood vessels that supply the endometrium and it converts that lining into its secretory phase when it's going to be most receptive to the embryo implanting in the lining.

Progesterone as a contraceptive

Progesterone makes the cervical mucus much thicker: it prevents extra sperm from coming up in the reproductive tract. It’s basically a contraceptive within the second half of the cycle.

Progesterone and the thermogenic effect

Progesterone is responsible for the thermogenic changes in a menstrual cycle. For example, when you check your temperature to monitor your ovulation, it’s basically the presence of progesterone that you detect when you see a rise in basal body temperature.
“Indeed, a lot of my clients ask why they are so hungry before their period. It’s the thermogenic effect in the luteal phase, that tiny temperature increase that impacts your metabolic rate slightly, so it’s normal to have an increase in appetite.”
Stefanie Vakalas, The Dietologist

Progesterone and pregnancy

The role of progesterone in conception

In the second half of the cycle, after ovulation, the endometrium matures. There are four days, called the window of implantation, which is when the endometrium is most prime to accept an embryo and progesterone is the hormone that makes that endometrium most receptive.

Progesterone also helps modulate the immune responses of the mother. So that makes the immune system more accepting of the implantation of the embryo.

It helps to reduce miscarriage and also helps to prevent preterm labour. So we use progestogens to help reduce that later on in pregnancy. In fact, when you do drop your progesterone levels naturally in the later stages of pregnancy it facilitates the onset of labour. So progesterone plays a very important role throughout pregnancy.

Even postpartum, progesterone plays an important role as it will inhibit lactation. So after the delivery, we don’t want progesterone to be around because we want women to produce breast milk.

Progesterone and IVF

The role of progesterone in an IVF cycle

As a fertility doctor here in Perth, I explain to patients who come and see me, that there are two parts to an IVF cycle.

The first one is what we call ‘controlled ovarian hyperstimulation’. This happens over the first couple of weeks in the IVF cycle.

“During that time, we are giving you these high doses of pituitary hormones and grow a whole heap of follicles all at once, as you want oestrogen to stimulate the growth of the lining. And that will happen from the growth of these many follicles.”
Dr Tamara Hunter, IVF doctor Perth
Then we give you a trigger injection, and about 12 to 24 hrs later, you get that maturation of the follicles. They switch from producing predominantly oestrogen to predominantly progesterone, and then you are getting progesterone production from those follicles.
“That is when progesterone is becoming important because it is maturing the lining. Once those eggs are collected and mixed with sperm in the lab, the progesterone in the body is doing its job to mature the lining so that we can allow a woman to have a fresh embryo transfer.”
Dr Tamara Hunter, IVF doctor Perth

So you may wonder, if the progesterone in the body is maturing the lining, why do we still give you a supplement?

During egg collection, we suck the fluid out of the follicle. The fluid contains granulosa cells and they are the ones that produce the hormones. So by stripping the follicles out, we reduce their ability to produce enough progesterone in the luteal phase to support the pregnancy. And that’s why we prescribe a supplement in the form of a gel, pessaries, or tablets.

Unfortunately, when we see low levels of progesterone, or when progesterone levels drop in pregnancy, this may lead to miscarriage. That’s why so many women worry about their progesterone levels.

“My takeaway message is: go and speak to a reproductive endocrinologist like myself before jumping to conclusions. Ensure that a trained fertility specialist is monitoring your progesterone levels and supplementing you appropriately if needed.”
Dr Tamara Hunter, IVF doctor Perth

Dr Tamara Hunter is a Fertility Specialist in Perth and specialised in IVF treatment. She is the only female CREI-certified specialist in Western Australia.

Listen to the full episode:
The Dietologist

Tamara also does a weekly Q&A on her Instagram profile so follow her there if you have a question that you want her to answer: @drtamara.hunter and @woom.womenshealth.