Can Soy Isoflavones Help Me Get Pregnant?

If you’re trying to conceive, you may have heard that soy isoflavones can help boost fertility. Soy contains compounds called phytoestrogens that mimic estrogen in the body. But is upping your soy intake or taking soy supplements proven to increase conception chances? Let’s take a closer look at what the research says.

What are Soy Isoflavones?

Soy isoflavones are a class of phytoestrogens found naturally in soybeans and soy products like edamame, tofu, and tempeh. The main isoflavones in soy are genistein and daidzein.

These plant compounds can bind to estrogen receptors and exert mild estrogenic and anti-estrogenic effects in humans. Soy is considered a weak estrogen or SERM (selective estrogen receptor modulator).

Some fermented soy products like miso and tamari also contain phytoestrogens. However, soy protein isolates and textured vegetable protein found in processed foods may not.

Proposed Benefits for Fertility

Here are some of the ways soy isoflavones may potentially support fertility:

• Lengthen short menstrual cycles – Soy mimics estrogen, which may help lengthen luteal phases under 10 days.
• Boost low estrogen levels – Soy acts like estrogen in the body and may improve estrogen levels in some women.
• Increase cervical mucus – Soy isoflavones appear to increase cervical mucus, which helps sperm travel.
• Regulate ovulation – Soy may help control irregular ovulation in women with PCOS.
• Reduce FSH levels – Soy can lower high follicle stimulating hormone in some infertility cases.
• Support egg quality – Antioxidants like genistein may protect eggs from damage and chromosomal issues.
• Reduce inflammation – The anti-inflammatory effects of soy isoflavones could aid fertility.
• Relieve menopause symptoms – Soy supplements may help relieve perimenopause, which can otherwise hinder fertility.

What Does the Research Show?

Studies reveal mixed findings about soy and fertility benefits:

• Soy supplements may help some women with PCOS ovulate and get pregnant. One study found taking 35-135 mg of soy isoflavones daily improved ovulation and increased progesterone levels.
• A 2018 review study concluded soy-based supplements significantly increased pregnancy rates in women with endometriosis.
• However, other research shows soy didn’t increase conception rates for women with unexplained infertility. Soy also didn’t improve egg quality or IVF outcomes in other studies.
• For men, soy supplements don’t appear to significantly affect sperm parameters or testosterone levels according to current research.
• Safety during pregnancy is uncertain. Since soy acts like estrogen, high amounts may pose concerns for fetal development. Limited intake as part of a diet is likely fine.

Soy isoflavone supplements may support fertility for some women, but they are not proven fertility boosters overall. More large scale studies are still needed.

Are Soy Foods Just As Good as Supplements?

Getting soy isoflavones from whole soy foods may offer similar benefits to supplements without the risks of concentrated doses. Whole soy also provides additional nutrients for fertility like protein, antioxidants, B vitamins, iron, zinc and magnesium.

Enjoy a few servings of soy foods per week as part of an overall fertility diet, such as:

• Tofu, edamame, tempeh
• Miso soup
• Soy nuts or seeds
• Soy milk or yogurt
• Whole soybeans

Focus on organic, non-GMO soy sources to limit pesticide exposures that could interfere with conception.

Should You Take Soy Isoflavone Supplements?

Soy isoflavone supplements haven’t been proven definitively to increase conception odds for most women. Effects seem limited to specific fertility issues like PCOS and endometriosis.

While supplements may help regulate ovulation and hormones, they also introduce higher concentrations of phytoestrogens than what’s found in food. This may skew estrogen levels too far or negatively interact with fertility medications.

Talk to your doctor before taking any soy isoflavone supplements, especially if you have hormonally driven infertility issues or are undergoing treatments like IVF. Targeted supplementation combined with medical protocols may be beneficial in some cases, but don’t take them in place of other therapies.

For most trying to conceive naturally, focus first on a healthy diet, lifestyle habits, and ovulation tracking. Then consider adding a few servings of whole soy foods for their beneficial vitamins, minerals, protein, and antioxidants. Soy in moderation may support fertility, but soy supplements are no guarantee for improving conception odds.