In this article:
You may see it referred to in short as P4 or simply “prog.”
Before Pregnancy
Even before conception, progesterone quietly prepares your body for a potential pregnancy. Here’s how it works:- Thickens the uterine lining to help the embryo implant securely
- Initiates the luteal phase of the menstrual cycle
- Supports early implantation by creating a receptive environment
- Encourages blood flow and nutrients in the endometrium
During Pregnancy
Once the embryo implants in the uterus, progesterone helps maintain early pregnancy. It:- Prevents menstruation by sending signals to the body that conception has occurred
- Relaxes the uterine muscles to prevent early contractions
- Helps the immune system accept the embryo, which carries foreign genetic material
- Prepares the breasts for lactation
- Supports the development of the placenta
In assisted reproduction cycles, continued supplementation is often advised through the first trimester to ensure stability during this transition.
Different Forms of Progesterone in Fertility Treatments
If your body doesn’t produce enough progesterone naturally or if you're undergoing fertility treatments, you may be prescribed supplemental progesterone. This can be administered in different ways:Vaginal suppositories
- Compounded by a pharmacy
- Typically used two to three times a day
- Can be waxy and messy
- Applied once daily
- Often used in assisted reproductive treatments
- Mild discharge is a possible side effect
- Used two to three times daily
- Often recommended for people under 35
- Approved for supplementation, not for full hormonal replacement
- Administered once daily into the buttock
- Require a thicker needle, and it may be painful
- Difficult to self-administer without assistance
Why Progesterone Matters During IVF or IUI
In IVF or IUI, your natural cycle is often altered due to stimulation medications. As a result, your body may not produce enough progesterone on its own. In these situations:- Supplementation is critical to support the embryo
- Progesterone helps the embryo gently attach and stay secure on the uterine wall, supporting early pregnancy.
- It encourages the uterus to remain calm and stable
Other Benefits of Progesterone
Though most known for its role in pregnancy, progesterone also contributes to general well-being. Some additional benefits include:- Progesterone supports bone strength and helps lower the risk of developing osteoporosis over time.
- Helps regulate weight by assisting with fat metabolism
- Balances blood sugar levels, reducing cravings for sugary foods
- Acts as a mild diuretic to reduce bloating and water retention
Side Effects and Important Warnings
Like any treatment, progesterone may cause side effects, though many people tolerate it well. The most commonly reported ones include:- Drowsiness or fatigue
- Fluid retention and bloating
- Headaches and dizziness
- Breast tenderness
- Mild abdominal cramping
- Mood changes, including sadness or irritability
- Vaginal discharge
- Urinary discomfort
FAQs on Understanding Progesterone's Role in Pregnancy From Conception to Birth
- Can low progesterone prevent pregnancy?
Yes, low progesterone can hinder implantation or cause the uterine lining to shed too early, making it difficult to sustain a pregnancy. - For how long is progesterone needed during IVF?
It is commonly continued until 10 to 12 weeks of pregnancy, or until the placenta can take over hormone production. - Can foods increase progesterone naturally?
Certain foods may support overall hormonal balance, but they cannot replace medical supplementation during fertility treatment. - Will progesterone delay my period?
Yes, high progesterone levels signal your body to withhold menstruation, which is why they are often used in early pregnancy support. - Is it safe to stop progesterone if I feel fine?
No. You should never stop progesterone supplementation unless instructed by your doctor. Sudden withdrawal can destabilise the pregnancy.
