During the luteal phase, the body goes through a number of significant changes that get it ready for pregnancy. Let’s take a more in-depth look at what goes on during this phase as well as what it indicates if it lasts for a longer or shorter amount of time than usual.
The menstrual cycle is divided into four stages. Each phase serves a distinct purpose:
- When you have your period, you are said to be menstruating. In the absence of pregnancy, your body is removing your uterine lining from the preceding cycle.
- Follicles grow during the follicular phase, which overlaps with menstruation for the first few days. In most cases, one follicle will grow larger than the others and deliver a mature egg. This indicates that the follicular period has ended.
- The mature egg is expelled during ovulation.
- When the egg begins to travel down the fallopian tube, the luteal phase begins. This phase will terminate when your next period starts.
What happens during the luteal phase of the menstrual cycle
The luteal phase of your menstrual cycle corresponds to the second half of your period. It begins after ovulation and continues until the first day of the first menstruation that you have.
After the egg has been released from the follicle, it will begin its journey down the fallopian tube, where it has the potential to meet sperm and become fertilized. After then, the follicle undergoes a transformation. After being depleted of its contents, the sac seals itself off, becomes yellow, and morphs into a new structure known as the corpus luteum.
Progesterone and a small amount of estrogen are both secreted by the corpus luteum. The lining of your uterus is thickened by the hormone progesterone, which makes it possible for a fertilized egg to implant. Within the lining, blood vessels begin to grow. These veins will supply the embryo that is developing with oxygen and nourishment as it grows.
In the event that you get pregnant, your body will also initiate production of human gonadotropin (hCG). The corpus luteum is kept in good condition by this hormone.
The corpus luteum is able to maintain its production of progesterone until approximately the tenth week of your pregnancy thanks to HCG. After then, the placenta is in charge of the creation of progesterone.
Your levels of progesterone will continue to climb as your pregnancy progresses. Here’s a broad guide:
- first trimester: 10 to 44 nanograms per milliliter (ng/mL) of progesterone
- second trimester: 19 to 82 ng/mL
- third trimester: 65 to 290 ng/mL
If you do not become pregnant during this phase, the corpus luteum shrinks and dies, transforming into a little bit of scar tissue. Progesterone levels will fall. During your menstruation, the uterine lining will shed. The cycle will then be repeated.
Length of the luteal phase
The length of time that one spends in their usual luteal phase might range anywhere from 11 to 17 days. In the majority of cases, a woman’s luteal phase will last between 12 and 14 days.
If your luteal phase lasts for fewer than 10 days, then it is considered to be a short phase. In other words, you have a short luteal phase if the time between ovulation and the first day of your period is ten days or less.
A luteal phase that is too brief does not allow the uterine lining to grow and mature to the point where it can adequately support a growing fetus. Because of this, becoming pregnant may be more of a challenge for you, or it may take you longer to conceive a child.
There is a possibility that a hormone imbalance, such as polycystic ovarian syndrome, is the cause of a prolonged luteal phase (PCOS). Or, the length of time that has passed since your last ovulation could be a sign that you are pregnant but haven’t yet recognized it as such.
It is not normal for the duration of your luteal phase to fluctuate as you get older. However, as you grow closer to menopause, your levels of progesterone may decrease while you are in this phase.
Short luteal phase causes and therapy
A short luteal phase can indicate a condition known as luteal phase defect (LPD). The ovary produces less progesterone than typical in LPD. Alternatively, the uterine lining does not develop in response to progesterone as it should. Infertility and miscarriage can result from LPD.
A short luteal phase could also be due to lifestyle issues. Women having a shorter luteal phase were shown to be more prone to smoke than those with a longer phase in one study. Smoking may shorten this phase by decreasing your body’s production of estrogen and progesterone.
Your doctor can treat LPD with the following medications to increase your chances of becoming pregnant:
- the infertility medication clomiphene citrate (Serophene) or human menopausal gonadotropins (hMG), which induce follicular growth
- hCG to stimulate corpus luteum progesterone production
- Progesterone can be taken orally, via injection, or as a vaginal suppository.
Temperature monitoring to determine phase
Tracking your basal body temperature can help you establish if you’ve ovulated and are in the luteal phase (BBT). This is your temperature when you first wake up, before you even get out of bed to use the restroom or brush your teeth.
During the early half of your cycle (follicular phase), your BBT will most likely be between 97.0 and 97.5°F. Your BBT will rise when you ovulate since progesterone boosts heat generation in your body.
Your basal body temperature should be roughly 1°F higher during the luteal phase of your cycle than it was during the follicular phase. Look for a temperature increase to indicate that you’ve ovulated and entered the luteal phase.
The luteal phase, when the body prepares for pregnancy, can be a good predictor of fertility. Consult your doctor if you suspect that you have a protracted or short luteal phase or that you do not ovulate. They can discover and treat any medical issues impacting your period.
If you’re under 35 and have been trying to conceive for at least a year without success, consult your health care physician or a fertility specialist. You could have a treatable fertility issue. If you are 35 or older, consult a doctor after 6 months of trying.