Does Having an Ovary Removed Affect Fertility?

Losing one ovary reduces your total egg supply but does not eliminate your ability to conceive. Studies consistently show that women with a single remaining ovary can become pregnant both naturally and through assisted reproduction, with live birth rates that are statistically comparable to those of women with two ovaries. The picture is more nuanced than a simple yes-or-no, though, because how much your fertility is affected depends on your age, the reason the ovary was removed, and whether the remaining ovary is healthy.

What Happens to Your Egg Reserve

Your ovaries hold a finite pool of eggs from birth, and removing one physically eliminates roughly half of that pool. Blood markers confirm this shift. Women with one ovary tend to have lower levels of anti-Müllerian hormone (AMH), the protein that reflects how many eggs remain. One study comparing women with one ovary to those with two found that the single-ovary group had about half the AMH level, and their follicle-stimulating hormone (FSH) was higher, a sign the body is working harder to stimulate egg growth from what is left.¹ A separate analysis of women who had undergone unilateral removal found AMH levels were about 54% lower than in controls.²

These numbers can feel alarming, but AMH is a measure of quantity, not quality. A lower AMH tells you that fewer eggs are available for any given cycle; it does not mean the eggs that remain are less capable of producing a healthy pregnancy. The practical consequences of a lower reserve matter most at the extremes: if you are younger and your remaining ovary is healthy, the reduction may be largely invisible in day-to-day fertility. If you are already in your late thirties or early forties, though, starting with a halved reserve gives you less of a buffer as natural age-related decline continues.

The Remaining Ovary Compensates

One of the more encouraging findings in reproductive biology is that the lone remaining ovary does not just sit there passively doing half the work. Research in both animals and humans shows that after one ovary is removed, the remaining ovary ramps up its activity. In rat models, the surviving ovary undergoes rapid changes including an increase in the number of mature follicles ready to release an egg, along with a measurable increase in ovarian weight.³

In humans, the compensation works slightly differently than in rodents. The remaining ovary does not create new eggs from scratch. Instead, more of the eggs already sitting dormant in the ovary’s reserve get recruited into the active growth phase each month. A review of the evidence confirmed that the remaining ovary compensates in follicular yield after removal of the other, consistent with the animal data.⁴ A broader review noted that the ovulatory rate among the growing follicles increases, allowing the body to maintain its cycle rhythm even with a single ovary.⁵

This compensatory mechanism is why many women with one ovary continue to ovulate regularly and menstruate on a normal schedule. The body recognizes the reduced egg supply and adjusts its hormonal signaling to coax more follicles to grow in each cycle. It is not a perfect fix, and it does not restore your total egg count, but it keeps the month-to-month machinery of ovulation running surprisingly well.

Natural Conception With One Ovary

The question most people really want answered is whether they can get pregnant on their own after losing an ovary. The honest answer is that many women can, but the odds depend heavily on individual circumstances. A study that followed women who had an ovary removed due to ovarian torsion (a sudden twisting of the ovary that cuts off blood flow) found that about 46% achieved spontaneous pregnancies afterward.⁶ That means over half did not conceive on their own, which sounds discouraging until you consider that the study population included women of varying ages and circumstances, and infertility has many causes beyond ovarian reserve.

The torsion study is useful because torsion strikes somewhat randomly and does not typically involve an underlying condition that would impair fertility on its own. When an ovary is removed because of endometriosis or a large cyst, additional factors like pelvic scarring or the disease itself can complicate the fertility picture beyond the simple loss of one ovary. So the roughly one-in-two spontaneous pregnancy rate from the torsion cohort gives a reasonable ballpark for how one-ovary status alone affects natural conception, separate from the disease that led to surgery.

IVF and Assisted Reproduction Outcomes

If natural conception does not happen, the next question is whether IVF or similar treatments still work well with a single ovary. Here the evidence is genuinely reassuring. One study compared IVF outcomes in women with one ovary versus two and found that the medication doses needed, the number of eggs retrieved, and the number of embryos transferred were all statistically similar between the groups.⁷

Live birth rates tell the same story. A study tracking women through up to five IVF cycles found that the average live birth rate across those cycles was about 13% per cycle for single-ovary women and 15% for those with two ovaries. The difference was not statistically significant. In fact, the single-ovary group had their peak live birth rate in the third cycle at 27%, compared to 19% in the fourth cycle for the two-ovary group.⁸ Separately, a larger database analysis confirmed that clinical pregnancy rates, live birth rates, and miscarriage rates were comparable between one-ovary and two-ovary patients undergoing assisted reproduction.¹

The compensatory follicular recruitment described earlier likely explains why IVF results hold up. When a fertility specialist stimulates the remaining ovary with hormones, it responds by maturing a reasonable number of eggs because its baseline recruitment has already increased. You may not produce quite as many eggs per retrieval as someone with two ovaries, but the gap is smaller than you’d expect, and it generally does not translate into a meaningful difference in the chance of taking home a baby.

Why the Reason for Surgery Matters

Not all oophorectomies are created equal from a fertility standpoint. The underlying condition that led to surgery can independently affect your remaining ovary and reproductive potential. Endometriosis is a prime example. Even when the affected ovary is removed, endometriotic tissue can be present elsewhere in the pelvis, and the disease can compromise the health of the remaining ovary. Research on ovarian cyst removal found that AMH dropped significantly after surgery for endometriosis cysts, more so than after removal of simpler cysts.⁹

A comparison of early AMH decline after laparoscopic ovarian cyst removal reinforced this pattern. Women who had endometrioma or teratoma removed experienced AMH drops of roughly 26-28%, significantly steeper than the approximately 12% drop seen in women with other benign cysts.¹⁰ These figures are for cyst removal rather than full ovary removal, but they illustrate how the type of pathology influences the overall damage to egg reserve. If your surgeon removes an entire ovary for a straightforward reason like torsion, the remaining ovary is likely unaffected. If the surgery was prompted by endometriosis, the remaining ovary may already be somewhat compromised.

Borderline ovarian tumors are another case worth knowing about. In women who wanted to preserve fertility, studies found that whether the surgeon performed a cystectomy (removing only the tumor) or removed the whole ovary and tube did not significantly affect the chance of later conception. The type of surgical procedure also did not influence the rate at which the tumor came back.¹¹ This is useful because it suggests that when a complete ovary removal is deemed the safest option for a borderline tumor, it does not appear to penalize fertility more than a more conservative approach would.

Fertility After Ovarian Cancer Surgery

A diagnosis of early-stage ovarian cancer raises uniquely high stakes: remove enough tissue to treat the cancer while trying to preserve the ability to have children. Fertility-sparing surgery for early ovarian cancer typically involves removing the affected ovary and its fallopian tube while leaving the other ovary and the uterus intact. The evidence suggests this approach does not lead to worse pregnancy outcomes compared to the general population.

A study comparing first pregnancies after fertility-sparing cancer surgery to pregnancies in healthy women found no significant increase in preterm birth (about 14% versus 11%), low birth weight, severe complications for the mother, or problems for the newborn.¹² That is a remarkable finding because it means the cancer surgery itself, including the loss of an ovary, does not appear to raise the risk of the kinds of complications women worry about most during pregnancy. The caveat is that these women had early-stage cancer and were carefully selected as candidates for the fertility-sparing approach. Women with more advanced disease or those who need chemotherapy face a more complicated fertility picture.

The Menopause Clock Speeds Up Slightly

Losing an ovary means you are drawing from a smaller egg reserve for the rest of your reproductive life. One long-term consequence is that menopause tends to arrive a bit earlier. A study tracking this found that women who had undergone removal of one ovary reached menopause about 1.8 years sooner than women with both ovaries intact, at an average age of roughly 49.5 compared to 51.3.¹³

That 1.8-year shift sounds modest, and for most women it is. But the study also found that the younger you were when the ovary was removed, the earlier menopause tended to arrive. If you had surgery at 25, the acceleration may be negligible. If you had it at 38, shaving nearly two years off an already shortening timeline could matter when you are trying to conceive in your early forties. The same study also found that smoking independently hastened menopause, so lifestyle factors can compound the effect.

For fertility planning purposes, the practical takeaway is that losing an ovary slightly narrows the window during which conception is possible. If you are planning to delay pregnancy, this is worth factoring into your timeline, though the shift is not dramatic enough to force a complete rethinking of your plans.

Fertility Preservation When Surgery Is Planned

When there is advance notice that an ovary needs to come out, fertility specialists can take steps to preserve eggs or ovarian tissue before or during the procedure. The standard option is to undergo ovarian stimulation and egg freezing before surgery. This is well-established and gives you a bank of frozen eggs or embryos to use later.

A newer approach combines ovarian tissue cryopreservation with in vitro maturation of eggs harvested directly from the removed ovary. Research on this combined strategy found that women who had ovarian tissue frozen alongside retrieval of immature eggs that were then matured in the lab achieved a yield of about four usable eggs on average in post-pubertal patients.¹⁴ The maturation rate was around 35%, which is lower than what you’d get from standard IVF, but the advantage is that it extracts additional value from the ovary that would otherwise be discarded. Pre-pubertal patients, such as young girls undergoing oophorectomy, had similar egg yields, and their frozen ovarian tissue showed a higher density of dormant follicles, reflecting their younger age.

The “spreading eggs across baskets” philosophy is especially relevant when the surgery is for cancer or a genetic risk condition like BRCA mutations, where the ovary is being removed preventatively rather than because it has already failed. Having both frozen eggs and frozen ovarian tissue gives you two independent routes to future pregnancy: the eggs can be thawed and fertilized conventionally, while the ovarian tissue could potentially be transplanted back later to restore natural hormone production and even allow spontaneous conception.

Surgical Technique and Tissue Damage

How the ovary is removed can affect the health of tissue that might be preserved for future use. Research using a porcine model examined whether the energy device used during laparoscopic surgery damaged nearby ovarian tissue. The study found that an ultrasonic energy device altered the metabolic health of the ovarian cortex, reduced follicle development, and lowered estradiol production in tissue near the dissection site compared to control tissue.¹⁵ This matters most for pediatric patients whose ovarian tissue is being cryopreserved during surgery, but it has implications for anyone whose surgeon is trying to preserve usable tissue from the removed ovary. If fertility preservation is part of your surgical plan, it is worth discussing with your team how the removal technique might affect tissue quality.

Bone and Cardiovascular Health After Losing an Ovary

Fertility is not the only concern after oophorectomy. Ovaries are endocrine organs that produce estrogen well beyond the reproductive years, and removing one can have downstream effects on bone density and cardiovascular health. These effects tend to be more pronounced when both ovaries are removed, but unilateral oophorectomy is not entirely without consequences.

A study of high-risk women who underwent oophorectomy found that bone mineral density decreased by about 8.5% in the lumbar spine and nearly 6% in the hips over just 18 months after surgery.¹⁶ While that study focused on bilateral removal in a high-risk population, research on postmenopausal women showed that even women who had undergone prior oophorectomy experienced faster bone loss and faster thickening of the carotid artery wall (an indicator of cardiovascular aging) compared to women who kept their ovaries intact. This difference became more pronounced as the years since menopause accumulated.¹⁷

For a younger woman focused on fertility after losing one ovary, these long-term skeletal and vascular effects are not immediate worries. But they are worth knowing about because they reinforce the principle that ovaries serve functions beyond reproduction. If you have lost one ovary and are approaching menopause earlier than average, conversations with your doctor about bone density monitoring and cardiovascular risk become relevant sooner than they would for someone with both ovaries intact. Hormone replacement therapy after menopause can offset some of these effects, though the decision involves its own trade-offs that are beyond the scope of fertility alone.

When Age Compounds the Loss

Age is the single biggest modifier of how much losing an ovary matters for fertility. A 25-year-old who loses one ovary still has hundreds of thousands of eggs in reserve, strong compensatory capacity, and years of fertile cycles ahead. A 37-year-old in the same situation starts with a reserve that is already declining steeply by natural design, and cutting it in half creates a tighter margin.

This is not just theoretical. The earlier menopause data shows that the effect of oophorectomy on menopausal timing scales with the age at surgery.¹³ The compensatory mechanism in the remaining ovary also appears to be more robust in younger women, whose ovarian tissue is more responsive to hormonal signals. If you are in your twenties or early thirties and have lost an ovary, the research broadly suggests that your fertility trajectory will look close to normal. If you are in your late thirties or older, the loss accelerates a timeline that was already speeding up, and proactive fertility planning (whether that means trying to conceive sooner or freezing eggs) becomes more important.

None of this means that a 39-year-old with one ovary cannot conceive. Many do, both naturally and with assistance. But the margin for delay is thinner, and the standard advice to “get your fertility checked” after oophorectomy carries more urgency when age is already working against you.