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Progesterone & Getting Pregnant: How Is It Connected?

What Is Progesterone?

Progesterone is a naturally occurring hormone that helps to regulate a functional menstrual cycle within the female reproductive organ. It is a form of steroid hormone that falls under the category of hormones called progestogens. Within the ovaries, the process of progesterone manufacturing takes place in a temporary endocrine gland called the corpus luteum, which is a remnant of a collapsed ovarian follicle during the second half of the menstrual cycle (luteal phase. Outside of the ovaries, progesterone is mainly produced by the adrenal glands and placenta throughout pregnancy.

This article will help explain what progesterone is, what does progesterone do and how to increase progesterone.

What Are The Functions Of Progesterone?

As initially stated, progesterone is a major physiologic determinant of a woman’s menstrual cycle and directly impacts a woman’s fertility and reproductive health. Progesterone has been nicknamed the ‘ pregnancy hormone due to its crucial role in creating a suitable uterine lining for implantation and preparing the body for pregnancy. Included below is a bullet list of other roles of progesterone in female reproductive health.

    • After fertilization has taken place, progesterone stimulates the growth of blood vessels which supply the uterine bed (endometrium) to prepare the womb for pregnancy.
    • Progesterone signals the glands within the endometrium to provide nutritional elements to sustain the early embryo.
    • It prepares the uterine lining to receive and implant the fertilized egg and subsequently sustain this relationship throughout the pregnancy.
    • It prohibits muscle contractions with the uterus that would contribute to a female’s body’s rejection of a fertilized egg.
    • Progesterone temporarily inhibits the female immune system to promote implantation and fetal cell development at later pregnancy stages.

How Does Progesterone Fluctuate Throughout The Ovarian Cycle?

Ovulating Regularly With PCOS
Image courtesy of The Bright Girl Guide by Demi Spaccavento.

To put it briefly, the ovarian cycle can be divided into 3 components; the follicular phase (pre-ovulation), ovulatory phase and luteal phase (post-ovulation). During the first phase of the ovarian cycle, the progesterone level remains relatively low. However, soon after ovulation has taken phase, the ovarian cycle will enter the luteal phase.

An interesting transformation occurs during the luteal phase, where the collapsed ovarian follicle, which used to house the dominant egg, changed into a structure called the corpus luteum. The Corpus luteum produces estrogen and progesterone, leading to a progesterone level spike halfway through the luteal phase.

If fertilization has taken place, the corpus luteum would continuously produce progesterone during the early stages of pregnancy. In this event, the placenta will produce a hormone called hCG that signals the corpus luteum to release progesterone until it degenerates, and the placenta fully assumes the role of progesterone production at later stages of pregnancy. However, if fertilization does not take place, the corpus luteum will naturally shrink away and cause a subsequent drop in progesterone levels. As a result, the endometrial lining will undergo a breakdown and is later shed as part of menstruation, which signals the beginning of another menstrual cycle.

How can I increase my progesterone?

Progesterone and Weight

Being overweight or underweight can disrupt your hormones and affect your menstrual cycle.

Maintaining a healthy BMI does not directly affect your progesterone levels but can assist in regulating your cycles and hormones. Estrogen and progesterone balance each other in the body, and throughout your menstrual cycle being overweight can lead to excess production of estrogen in the fat cells.

This can lead to estrogen dominance, even know you might have normal progesterone levels due to the high levels of estrogen might be causing you not to ovulate

Include Healthy Dietary Fats & Vitamins  

Having healthy fats in your diet will help regulate and balance your blood sugar levels and, in turn, assist with you increase your progesterone levels.

Studies have shown that improving your insulin sensitivity and having a well-balanced diet that includes healthy fats such as cholesterol will help increase progesterone production.

Getting healthy fats from good sources such as fatty fish, avocado, coconut oil, and grass-fed meat are all good choices and will help increase the amount of cholesterol you are getting into your diet, affecting your blood sugar levels leads to more progesterone production.

Another study has shown that having enough Zinc, Vitamin C, Magnesium, Vitamin B6 in your diet can assist with ovulation and production of progesterone. Taking Conceive Plus prenatal vitamins can assist in your intake of essential vitamins to help with PCOS and ovualtion.

Zinc increases the amount of follicle-stimulating hormone (FSH) that is made during your cycle, which helps support healthy ovulation.

Vitamin C may increase the effects that progesterone has during the menstrual cycle. Vitamin C has also been shown to increase progesterone levels and help resolve some luteal phase defects (LPD)

Magnesium is essential in many ways in the body, and it helps regulate your adrenal glands, which are essential for healthy hormone production, including progesterone.

Vitamin B6 is used to metabolise excess estrogen in your system, which can easily be depleted if you are suffering from estrogen dominance in your fertility hormones. eating vitamin B6 food can help reduce the amount of estrogen while increasing progesterone levels

How Does Progesterone Affect A Basal Body Temperature (BBT)?

Basal body temperature (BBT) charting is a method of predicting the advent of the fertile window to suggest an ideal time for well-timed intercourse for couples who are trying to conceive. It is a series of measurements of your daily waking-up temperature or the temperature when your body is at rest, which is later plotted on a Basal body temperature chart or graph for interpretation. The main idea of basal body temperature charting is to pinpoint the rise in BBT, which is caused by the spike in production of progesterone just right after ovulation has taken place.

How Does Progesterone Affect A Basal Body Temperature (BBT)?
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For women who have a regular cycle with no alteration from external factors such as hormonal contraceptives, it can be anticipated that the basal body temperature chart would show a biphasic pattern. This pattern can be broken down into 2 parts; it stays relatively low during the preovulatory phase but enters a higher reading during the middle of the menstrual cycle. As stated earlier, this shift in temperature is contributed by progesterone production by the corpus luteum and coincides with ovulation.

Therefore, a rise in basal body temperature can signal that ovulation has taken place and could signify a perfect time to try conceiving with minimal users’ errors. According to an article published by the University of Michigan, a woman’s Basal Body Temperature averages between 36.1-36.4 degrees Celsius and rises to 36.4 degrees Celsius to 37.0 degrees Celsius after ovulation.

How Is Basal Body Temperature (BBT) Measured?

There are various guidelines on how to attain an accurate basal body temperature reading, but in this article, readers are encouraged to remember the 3T’s of BBT charting; TIMING, TEMPERATURE AT REST AND THERMOMETER.

Timing: The most ideal time to take your BBT is when you have just woken up after at least 5 hours of sleep. To ensure consistency, take your BBT at around the same time every morning and note this reading on your BBT chart. Please also ensure that you take reading as accurate as possible, with no estimation or rounding off, to ensure that your BBT chart is dependable to predict your ovulation.

The temperature at rest: BBT is the measurement of your core body temperature at rest with no external factors that can alter your levels of body heat. This would mean that you should avoid vigorous physical activities that may elevate your core body temperature, smoking, eating or drinking before taking your BBT measurement.

Thermometer: Use a thermometer that is specifically designed for measuring BBT. A good BBT or ovulation thermometer should have a high recording sensitivity and can detect any value change as low as 0.01 degrees Celsius. The Fertility2Family’s BBT thermometer ticks all the boxes for a reliable fertility monitoring device for its high sensitivity, great user interface and affordable price.

What Information Does A Basal Body Temperature (BBT) Chart Carry?

1. The average length of your menstrual cycle

Your BBT chart would help to visualise the length of your menstrual cycle and detect any irregularities of your cycle length and potentially a reduced progesterone level. Although the textbook length of the menstrual cycle is known to be 28 days, this value may range from 21 to 40 days in some women.

2. The length of each phase

The typical bi-phasic pattern that is portrayed by the BBT chart essentially coincides with the pre-ovulatory phase and the luteal phase of the menstrual cycle. Due to this, you can estimate the length of your menstruation, pre-ovulatory and luteal phase of the menstrual cycle.

If your luteal phase is less than 10 days, you may be experiencing a condition called a short luteal phase or luteal phase defect secondary to low progesterone levels in most cases. Because this phase is crucial for the optimization of the uterine bed to receive and sustain a fertilized egg, this condition may make it difficult to become or stay pregnant.

3. Detection of fertility issues

If your BBT does not show the typical highs and lows of a typical BBT chart, it could signify that you are not ovulating as you should. Generally, after 2-3 cycles of accurate BBT charting, you may be able to predict the next window of ovulation in the next cycle based on your data. However, if your BBT is usually inconsistent and you are experiencing a hard time conceiving, this may indicate a disturbance in your regular physiologic hormone cycles as seen in cases of high body mass index (BMI), lifestyle changes, excessive physical stressors or poor nutrition. Alternatively, this could hint at other medical conditions such as polycystic ovarian syndrome (PCOS), thyroid issues or ovarian cysts.

4. Estimation of the ovulatory phase

The BBT method, technically speaking, does not predict when you are about to ovulate, but rather, the BBT thermal shift coincides approximately with the time of a full day after ovulation. In short, the rise in BBT caused by a spike in progesterone after the release of an egg lets you know that an egg is available to be fertilized. For couples who are trying to conceive, this would be a perfect time to have intercourse as percentages to become pregnant increase significantly during this window.

5. Occurrence of pregnancy

As mentioned earlier, progesterone is an important hormone to sustain a pregnancy. Therefore, if a pregnancy has occurred, your progesterone level, which correlates with your BBT, does not fall and remains consistently on the higher side. If you are using the BBT method and your BBT remains high after 15 days, you may want to take an early pregnancy test with the absence of menstruation, and you have been sexually active during the current cycle. If you are looking for reliable, quick and reasonably priced urine-based pregnancy kits, you should consider trying the trustworthy Fertility2Family’s home pregnancy test.


The biological relationship between basal body temperature (BBT), progesterone and fertility may seem difficult to understand. But, the interplay between these 3 factors, on the surface, is fairly simple. In a short glance, the rise in progesterone during the luteal phase (post-ovulatory phase) causes a rise in BBT, which a BBT or an ovulation thermometer can detect.

Progesterone rises during this phase to prepare a female’s body to sustain pregnancy through its various roles in uterine lining optimization. As the progesterone and, consequently, the BBT rises after ovulation, this would signal that an egg is available to be fertilised and would be a perfect time for couples who are trying to conceive of having intercourse.