Conceiving while lactating, although possible, is not necessarily easy for all women. Breastfeeding can affect fertility due to the hormone prolactin, which stimulates milk production and can suppress ovulation. Prolactin inhibits the release of Follicle-Stimulating Hormone (FSH) and Gonadotropin-Releasing Hormone (GnRH), both crucial for ovulation. Lacation can thus cause temporary infertility by inhibiting FSH and GnRH and preventing ovulation. Lactational amenorrhea (LAM) is a short-term, natural birth control method that can help prevent pregnancy while breastfeeding. This suppression can lead to delayed return of menstruation and irregular cycles in breastfeeding women. Some women may not ovulate regularly while nursing, making conception more challenging.

Originally published on October 30, 2018. Updated on August 26, 2024.

Fertility Awareness Method (FAM)

The Fertility Awareness Method (FAM), also known as natural family planning, is a technique that helps women monitor their fertility without using medications or medical devices. This method relies on observing and charting physiological signs throughout the menstrual cycle to determine the most fertile days.

Cervical Fluid (CF)

Cervical fluid (CF) is one of the most important indicators of fertility and plays a critical role in the reproductive process. The consistency, color, and quantity of cervical fluid change throughout the menstrual cycle, providing valuable insights into a woman’s fertility status. During the menstrual cycle, these changes are influenced by fluctuations in hormone levels, particularly estrogen and progesterone.

In the early phase of the cycle, often referred to as the follicular phase, cervical fluid is typically dry or sticky. This phase occurs immediately after menstruation when estrogen levels are still relatively low. The dry or sticky consistency of CF at this time is not conducive to sperm survival, forming a barrier to sperm entry into the uterus.

As the menstrual cycle progresses and estrogen levels rise in preparation for ovulation, cervical fluid becomes more abundant and undergoes a noticeable transformation in both texture and appearance. Initially, CF may turn creamy, indicating increasing fertility. This creamy CF is more conducive to sperm survival and movement but still does not represent peak fertility.

The most significant change in cervical fluid occurs just before ovulation, during the ovulatory phase, when estrogen levels peak. The cervical fluid becomes clear, stretchy, and slippery, resembling raw egg whites. This egg white cervical fluid is highly elastic and can stretch between the fingers without breaking, a key sign that ovulation is imminent. This type of CF creates an optimal environment for sperm, allowing them to swim more easily through the cervix to meet the egg in the fallopian tube. Egg white CF also helps to protect sperm from the acidic environment of the vagina, increasing their lifespan and enhancing the chances of fertilization.

The presence of egg white cervical fluid is a strong indicator that the body is preparing to release an egg, making it the most fertile period of the cycle. Women who are trying to conceive can use this sign to time intercourse for the best chance of pregnancy. After ovulation, cervical fluid typically becomes sticky or dry again as progesterone levels rise, marking the luteal phase of the cycle and the end of the fertile window.

Understanding the changes in cervical fluid can help women identify their fertile days, especially when used in conjunction with other fertility awareness methods like tracking basal body temperature. This knowledge empowers women to better understand their reproductive health and make informed decisions about family planning.

Basal Body Temperature (BBT)

Tracking basal body temperature (BBT) is a crucial component of the Fertility Awareness Method (FAM) and offers a reliable way to confirm ovulation. BBT is the lowest resting temperature of the body and is typically measured immediately upon waking before any physical activity or eating, as even minor movements can affect the accuracy of the reading. For the most precise results, BBT should be taken at the same time each morning, using a highly sensitive digital or basal thermometer that measures to at least one-tenth of a degree.

During the menstrual cycle, hormonal fluctuations cause subtle changes in BBT. In the first half of the cycle, known as the follicular phase, estrogen is the dominant hormone, keeping BBT relatively low. For most women, BBT during this phase ranges from about 97.0 to 97.7 degrees Fahrenheit (36.1 to 36.5 degrees Celsius).

As ovulation approaches, a surge in luteinizing hormone (LH) triggers the release of an egg from the ovary. Following ovulation, the hormone progesterone rises significantly to prepare the uterus for a potential pregnancy. Progesterone has a thermogenic effect, causing a slight but noticeable increase in BBT. Typically, BBT rises by about 0.5 to 1.0 degrees Fahrenheit (0.3 to 0.6 degrees Celsius) after ovulation and remains elevated throughout the luteal phase, which lasts about 12 to16 days.

The sustained rise in BBT after ovulation provides confirmation that ovulation has occurred. This is particularly valuable for women who are trying to conceive, allowing confirmation of the post-ovulatory phase of the cycle. However, because BBT only rises after ovulation, tracking the measurement is not a predictor of ovulation but rather a retrospective indicator.

For women who are breastfeeding, tracking BBT can be especially useful because lactation can cause irregular cycles and make predicting ovulation more difficult. By consistently charting BBT, women can determine whether they are ovulating and when their luteal phase begins, even if their menstrual cycles are irregular. This information can help them better understand their fertility patterns and optimize the timing of intercourse for conception.

In addition to confirming ovulation, BBT tracking can provide insights into overall reproductive health. For example, a consistently low BBT throughout the cycle may indicate a thyroid issue. A short luteal phase (less than 10 days of elevated BBT) could suggest luteal phase defect, a condition that can affect the ability to maintain a pregnancy.

To get the most accurate and informative data from BBT tracking, charting temperatures over several cycles and looking for patterns is crucial. This practice, combined with other FAM indicators like cervical fluid changes, can greatly enhance the understanding of fertility, whether a woman is trying to conceive, avoiding pregnancy, or simply monitoring her reproductive health.

Using FAM to Increase Chances of Conception

For women who are breastfeeding and trying to conceive, FAM can be an effective tool to identify ovulation despite irregular menstrual cycles. By carefully monitoring signs such as cervical fluid and BBT, determine when ovulation occurs becomes possible, thus optimizing the timing for conception.

In general, women using FAM may track their fertility signs daily. Each morning, they measure their BBT with a specialized thermometer and record the temperature on a fertility chart. Additionally, they observe their cervical fluid throughout the day, noting its consistency and amount. During the days when egg white cervical fluid is present, they are likely in their most fertile window.

Many women who use FAM while breastfeeding are able to successfully conceive, even with irregular cycles. The method helps them identify fertile days and confirms ovulation, giving them the information they need to increase their chances of pregnancy. By understanding and applying the principles of FAM, women can better navigate the challenges of trying to conceive while breastfeeding.