Why You Need to Take Estrogen During Your IVF Cycle

If you're about to undergo in vitro fertilization (IVF), your healthcare provider likely prescribed Estrace (a type of estrogen) to help you conceive.

Estrace is given to help stimulate the eggs to grow or during a frozen embryo transfer to help thicken the lining of the uterus to increase the chances of embryo implantation.

Read on to learn more about the benefits of estrogen treatment, how it's taken, the possible side effects, and why healthcare providers recommend Estrace (estradiol) during IVF.

What Is Estrace Used For?

Estrace is a tablet that contains estradiol—a form of estrogen that is made in the ovaries. During the menstrual cycle, estradiol levels increase, which causes the maturation and release of the egg and the thickening of the uterus lining to allow a fertilized egg to implant.

With IVF, Estrace is given to help stimulate the eggs to grow or during a frozen embryo transfer to help thicken the lining of the uterus to increase the chances of embryo implantation.

Progesterone—another hormone made in the ovaries—may also be given during IVF because it supports the uterine lining and helps an embryo implant and grow inside. An analysis of 19 studies published in 2020 found that taking both estrogen and progesterone improves chances of early pregnancy.

Another hormone that can be given during IVF is gonadotrophin-releasing hormone (GnRH). This hormone affects thyroid hormone levels, which in turn increases estrogen production.

How Is Estrace Taken?

Estrace is usually started on the first day of your period. Estrogen supplements come in the form of pills that you swallow or insert into your vagina, patches that stick to your belly, or injections into the muscle.

It is frequently given as a pill containing 2 milligrams of estradiol twice a day for about 14 days, although shorter or longer cycles may be used. In some situations, larger doses of estradiol may be recommended.

After about 14 days, progesterone is added along with the estradiol. This may be given vaginally or as an intramuscular injection. Estrace and progesterone are continued until the day of the pregnancy test (usually 12 days after embryo transfer). If the test is positive, these medications may be continued for several weeks. 

Who Shouldn't Take Estrace?

You shouldn't take estradiol if you have:

• Undiagnosed vaginal bleeding
• Liver disease
• Bleeding disorder
• Known or suspected pregnancy

You also shouldn't take estradiol if you've ever had a heart attack, stroke, blood clot, or cancer of the breast, uterus, cervix, or vagina. Check with your healthcare provider about the risks of taking Estrace with your medical history.

What Are the Side Effects?

Using estradiol for more than a year can increase your risk of blood clots, stroke, or heart attack. Estradiol has also been shown to increase the risk of cancer of the breast, uterus, or ovaries.

However, these risks are lower if low doses are used for less than a year. Taking estrogen in combination with progesterone also helps offset the risks. Other possible side effects may include:

• Light vaginal bleeding 
• Upset stomach
• Nausea, vomiting
• Vaginal discharge
• Vaginal itching
• Weight gain
• Bloating
• Swelling of the hands, feet, ankles
• Headaches
• Breast tenderness or pain
• Skin irritation
• Rash

Do not stop taking estradiol before consulting with your fertility doctor first. This could affect your IVF cycle.

Talk to your healthcare provider if you have any serious side effects, including:

• Nausea or vomiting that doesn't stop
• Mental changes, such as depression or memory loss
• Breast lumps
• Unusual vaginal bleeding (such as spotting, breakthrough bleeding, prolonged/recurrent bleeding)
• Increased or new vaginal irritation, itching, odor, or discharge
• Severe stomach pain
• Yellowing eyes or skin
• Dark urine
• Swollen hands, ankles, or feet
• Increased thirst or urination

Although these side effects are very rare, get medical help right away if you experience:

• Pain in the chest, jaw, or left arm
• Unusual sweating
• Sudden, severe headache
• Weakness on one side of the body
• Confusion, trouble speaking, or sudden vision changes
• Pain, redness, or swelling of legs
• Tingling, weakness, or numbness in the arms or legs
• Trouble breathing
• Coughing up blood
• Sudden dizziness or fainting

Summary

Fertility doctors prescribe estrogen to patients undergoing IVF to help stimulate the eggs to grow or during a frozen embryo transfer to help thicken the lining of the uterus and help increase the chances of embryo implantation. Estrogen supplements come in pills that you swallow or insert into your vagina, patches that stick to your belly, or injections into the muscle.

Most short-term side effects range from light vaginal bleeding to skin rash. If you take an estrogen-based medication and have symptoms that concern you, speak to your healthcare provider or pharmacist.