What Happens During the Luteal Phase of the Menstrual Cycle?

If you're tracking your menstrual cycle or trying to get pregnant, chances are you've heard about the luteal phase. One of the four phases of the menstrual cycle, it occurs prior to the onset of your period, and it prepares the uterus for possible implantation and pregnancy.

Like other parts of the menstrual cycle, the luteal phase comes with its own set of signs, symptoms, and purposes. We turned to experts to learn more about this segment and its role in reproduction. Keep reading if you're trying to conceive or just curious about your body's functioning.

What Is the Luteal Phase and Why Is It Important?

The luteal phase takes place in the second half of your menstrual cycle, and it follows the follicular phase, which is when the production of ovary follicles takes place. "During the luteal phase of the cycle, the uterine lining is thickened, ultimately preparing the uterus for pregnancy," says Melanie Bone, OB-GYN and U.S. Medical Director of Daye. The other two parts of the menstrual cycle (ovulation and menstruation) can overlap with these phases.

The luteal phase is linked closely to the body's production of progesterone, a hormone that helps sustain early pregnancy if implantation occurs. "The release of progesterone is what leads to the thickening of the uterine lining and, if pregnant, the body will continue to produce progesterone to build the uterine wall for embryo implantation," says Dr. Bone. If you do not happen to become pregnant, progesterone levels fall in the body, which prompts your uterus to shed its lining, resulting in your monthly period.

But the luteal phase and progesterone aren't only important for pregnancy. "Progesterone is crucial for strong bones, healthy sleep cycles, and metabolic health," adds Dr. Bone. Thus, it's helpful to keep track of your luteal phase's length to make sure you're within normal parameters.

How Long Does the Luteal Phase Last?

Like everything related to one's menstrual cycle, the length of the luteal phase might be slightly different for everyone. "This phase usually starts around day 15 of a 28-day cycle and can last between 11 and 17 days, depending the general length of an individual's cycle," says Dr. Bone.

While everyone's cycle is different, you might want to note if your luteal phase is significantly shorter than the average length, as such abnormalities here can suggest gynecological and/or fertility issues.

"A short luteal phase (less than 11 days) can be a sign of a condition called luteal phase defect (LPD), meaning that the ovaries do not produce enough progesterone and the uterine lining does not build properly. This defect can lead to miscarriage or some fertility challenges," explains Dr. Bone.

With that in mind, it's important to know the signs of the luteal phase within a healthy body.

Signs of the Luteal Phase

The luteal phase begins at the second half of the menstrual cycle, leading up to one's period. "When in the luteal phase, there is a shift in the levels of progesterone in the body. As a result, folks may experience symptoms such as mood swings, anxiety, fatigue, bloating, skin breakouts, headaches, and breast tenderness," says Dr. Bone.

Frustratingly, these symptoms may also be related to early pregnancy, so it's important to keep track of your ovulation cycle, and if you are trying to conceive, your basal body temperature, to know the difference.

Can You Get Pregnant During the Luteal Phase?

It's important to know that without birth control, you can indeed get pregnant during most of your menstrual cycle. The luteal phase is no different, says Dr. Bone.

"Technically, yes, you can get pregnant during the luteal phase, however, only within the first two days, as an egg produced during your ovulation phase can only survive for 12-24 hours," she says.

If you suspect that your luteal phase is too short, it's important to speak to a health care provider, since it could make conceiving more difficult.

Your menstrual cycle plays a role in your overall health, and, if you are trying to have a baby, is strongly linked to your chances for conception. Speaking to an OB-GYN or health care provider about your luteal phase, as well as your menstrual cycle as a whole, can help you understand your body's signs so you can be well-prepared—no matter your goals.