Why Low Estrogen Can Cause Infertility and Make It Harder to Get Pregnant

When you’re trying to recover your period or thinking about having kids someday, it’s easy to focus on ovulation. After all, if you aren’t ovulating, you can’t get pregnant. But there’s another hormone that plays a huge role in fertility that doesn’t always get talked about enough: estrogen.

Estrogen is usually discussed in relation to menopause. What many people don’t realize is that hypothalamic amenorrhea (HA) can create a hormonal environment that shares some similarities with menopause, particularly low estrogen levels. Just because you’re younger doesn’t mean you’ll avoid the effects of prolonged estrogen deficiency. When I was recovering from hypothalamic amenorrhea, I mostly thought about getting my period back. I knew I wasn’t ovulating, but I didn’t fully understand everything that low estrogen was affecting behind the scenes. It wasn’t until I learned more about reproductive health that I realized estrogen isn’t just about having a period. It’s essential for preparing your body for pregnancy long before conception ever happens.

Estrogen is produced by the growing follicles in your ovaries during the first half of your menstrual cycle. As those follicles mature, estrogen levels rise, signaling that your body is getting closer to ovulation. When estrogen reaches a high enough level, it triggers the brain to release a surge of luteinizing hormone (LH), which causes the ovary to release an egg. If estrogen never rises enough, that LH surge may never occur, meaning ovulation doesn’t happen (KJK Hospital & Fertility Research Centre, 2018; Osnato, 2025).

This is one of the biggest reasons women with hypothalamic amenorrhea often struggle with fertility. When your brain senses that your body doesn’t have enough energy because of under-fueling, excessive exercise, chronic stress, or a combination of these factors, it conserves energy by reducing reproductive hormone production. Estrogen drops, ovulation stops, and pregnancy becomes much more difficult until your body feels safe enough to restart those processes.

But even if you do ovulate occasionally, estrogen still has several other important jobs. One of its biggest responsibilities is helping build the lining of your uterus. Each month, estrogen thickens the endometrium so that if an egg is fertilized, it has a healthy place to implant and grow. If estrogen remains too low, that lining may not develop adequately, making implantation more difficult (KJK Hospital & Fertility Research Centre, 2018; Osnato, 2025).

Estrogen also changes your cervical mucus throughout your cycle. Around ovulation, healthy estrogen levels create the clear, stretchy cervical mucus that many women recognize when tracking their cycles. This mucus isn’t just a sign that you’re fertile—it actually helps sperm survive and travel through the reproductive tract to reach the egg. Without enough estrogen, many women produce very little fertile cervical mucus, creating another obstacle to conception (Proov, n.d.).

One thing I think is important to remember is that low estrogen doesn’t always mean something is permanently wrong with your ovaries. In hypothalamic amenorrhea, the ovaries are often capable of functioning normally. They’re simply not receiving the hormonal signals from the brain that tell them it’s time to grow follicles and ovulate. That’s actually encouraging because it means that, for many women, this process can be reversed by restoring adequate energy availability and allowing the body to recover.

I know that’s often easier said than done. Recovery can feel painfully slow. It certainly did for me. I wanted my hormones to bounce back as soon as I started eating more, but my body needed much more time than I expected. It also needed me to gain back more weight than I originally thought it would. Looking back now, I’m grateful I trusted the process because my body was asking for what it needed, not what I wanted it to need.

Even if pregnancy isn’t something you’re thinking about right now, estrogen is still incredibly important. Healthy estrogen levels support strong bones, cardiovascular health, brain function, vaginal health, and overall well-being. When estrogen stays low for long periods, women may experience decreased bone density, vaginal dryness, low libido, sleep disturbances, mood changes, an increased risk of stress fractures, and other health concerns associated with estrogen deficiency (Osnato, 2025).

One of the hardest parts about hypothalamic amenorrhea is that you often don’t realize how many systems are being affected until you start learning about it. It isn’t just about missing a period. Your body is communicating that it doesn’t have enough resources to support reproduction, and that affects far more than your menstrual cycle.

The good news is that your body is incredibly resilient. For many women with hypothalamic amenorrhea, increasing energy intake, reducing energy expenditure when appropriate, managing stress, and giving the body enough time can allow estrogen levels to rise again. As estrogen returns, ovulation often follows, and fertility can improve.

If you’re in the middle of recovery, I know it can feel frustrating when things don’t happen on your timeline. Trust me, I’ve been there. But every meal, every snack, every rest day, and every step you take toward nourishing your body is helping create an environment where your hormones can recover. Your body isn’t working against you. it’s working to protect you. And with time, consistency, and patience, healing is possible.

Wondering if low energy availability could be affecting your hormones? Take our free Period Recovery Quiz to find out whether you may be experiencing hypothalamic amenorrhea and learn the next steps toward recovery.

References

KJK Hospital & Fertility Research Centre. (2018, December 18). Estrogen deficiency and infertility. [https://kjkhospital.com/estrogen-deficiency-fertility/](https://kjkhospital.com/estrogen-deficiency-fertility/)

Osnato, J. (2025). What causes low estrogen? Allara Health. [https://www.allarahealth.com/blog/low-estrogen-causes](https://www.allarahealth.com/blog/low-estrogen-causes)

Proov. Low estrogen & fertility: How to know if you need to boost estrogen production. [https://proovtest.com/blogs/blog/boosted-estrogen-production-fertility](https://proovtest.com/blogs/blog/boosted-estrogen-production-fertility)