Why You Need to Take Estrogen During Your IVF Cycle

If you and your partner are about to undergo in vitro fertilization (IVF), chances are your doctor has prescribed estrogen to help you conceive. If you have polycystic ovarian syndrome (PCOS), a condition that makes you estrogen dominant, an estrogen prescription may come as a surprise.

Side Effects of Taking Estrogen During IVF Cycle
Verywell / Brianna Gilmartin

Why Doctors Prescribe Estrogen

Estrogen supplementation during an IVF cycle involving gonadotropins or gonadotropin-releasing hormones is commonly used by many infertility specialists. One of the major hormones of pregnancy, estrogen, helps maintain the endometrial lining of the uterus.

Reproductive endocrinologists prescribe estrogen supplements to help your endometrium grow and prepare for a pregnancy.

Before the egg is implanted into your uterus, if your lining looks too thin, your doctor may prescribe more estrogen. The increased dosage may help thicken your lining, preparing your uterus for pregnancy. If you are using a donor egg, donor embryo, or a frozen embryo transfer, your doctor will most likely prescribe estrogen before your implantation date.

A meta-analysis published in Medicine looked at 11 studies involving estrogen supplementation plus progesterone as luteal phase support in those undergoing IVF.

Researchers concluded that taking both progesterone and estrogen supplements during IVF treatment after egg retrieval was associated with a higher clinical pregnancy rate than progesterone alone. Other outcomes such as ongoing pregnancy rate, fertilization rate, implantation rate, and miscarriage rate were found to be the same for both treatments.

What to Expect When Taking Estrace

Estrace (estradiol) is the form of estrogen most commonly prescribed. Your doctor will likely prescribe 2 milligrams (mg) two to three times a day. Some physicians may instruct you to insert the pill into the vagina instead of taking it by mouth. It is the same pill, just given in a different manner.

If you take Estrace vaginally, it's important to keep the following in mind. First, you may notice a blue-green discharge. This is nothing to be concerned about; it is only the pill fragments breaking.

Once you insert the pill, you should lay down for at least a half-hour to prevent the pill from falling out. If you are having difficulty with insertion, you can wear a latex glove to prevent the pill from breaking up under your fingernail.

While taking estrogen, your doctor will most likely want to monitor you using blood tests or ultrasounds. Periodic adjustments may be needed to optimize your hormone levels and endometrial lining. Make sure to follow your RE’s recommendations regarding Estrace dosing.

Side Effects

Side effects of estradiol and Estrace may include:

  • Spotting or light vaginal bleeding 
  • An upset stomach, nausea, or vomiting
  • Vaginal discharge or itching
  • Weight gain
  • Swelling or bloating
  • Headaches
  • Breast tenderness or pain 

Like any prescription medication, serious side effects can occur. If you are taking an estrogen-based medication and have symptoms that concern you, speak to your doctor or pharmacist. Do not stop taking Estrace or estradiol before consulting your physician as this could affect your IVF cycle.

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  1. Zhang XM, Lv F, Wang P, et al. Estrogen supplementation to progesterone as luteal phase support in patients undergoing in vitro fertilization: systematic review and meta-analysisMedicine (Baltimore). 2015;94(8):e459. doi:10.1097/MD.0000000000000459

  2. U.S. National Library of Medicine DailyMed. Label: Estrace—estradiol tablet. Updated May 31, 2018.