Ovarian torsion is a gynecological emergency in which an ovary twists around the ligaments that hold it in place, cutting off its own blood supply. Without blood flow, the ovarian tissue starts to die, which is why rapid diagnosis and surgery are critical. It affects people of all ages, from children to postmenopausal women, though it most commonly occurs during the reproductive years.
How Torsion Happens
The ovary is anchored inside the pelvis by two sets of ligaments: one connects it to the uterus, and the other suspends it from the pelvic wall. These ligaments also carry the ovary’s blood vessels. When the ovary rotates along these ligaments, it pinches off venous drainage first, causing the ovary to swell with trapped blood. If the twist is severe or sustained, arterial blood flow is also blocked, and the tissue becomes oxygen-starved. The result is an ovary that rapidly enlarges, sometimes to several times its normal size. In one ultrasound study, torsed ovaries measured an average of about 72 mm across, compared to roughly 16 mm for normal ovaries.
Sometimes the ovary twists and partially untwists on its own, a phenomenon called intermittent torsion. This creates waves of symptoms that come and go, which can make the condition harder to recognize and easier to dismiss.
What Increases Your Risk
The single biggest risk factor is having an enlarged ovary, usually from a cyst or mass. The American College of Obstetricians and Gynecologists notes that the risk of torsion increases when a pelvic mass exceeds 5 cm. A larger, heavier ovary has more momentum to swing and twist on its supporting ligaments. Common culprits include functional cysts, dermoid cysts, and benign tumors. Malignant masses, interestingly, are less likely to cause torsion because they tend to adhere to surrounding tissue.
Pregnancy raises the risk about fivefold, to roughly five cases per 10,000 pregnancies. This spike typically happens between the 6th and 14th weeks of gestation, driven by the growth of the corpus luteum cyst that supports early pregnancy. That cyst usually shrinks on its own by the second trimester, and the risk drops accordingly. Fertility treatments that stimulate the ovaries to produce multiple large follicles also increase the chance of torsion significantly.
What It Feels Like
The hallmark symptom is sudden, severe pelvic or lower abdominal pain, usually on one side. But the presentation is notoriously variable. The pain can be sharp or dull, constant or intermittent, and it sometimes radiates to the back, flank, or upper abdomen. That variability is part of what makes torsion so easy to mistake for other conditions like appendicitis, a ruptured ovarian cyst, an ectopic pregnancy, kidney stones, or even a urinary tract infection.
Nausea and vomiting are extremely common alongside the pain. In children and adolescents with lower abdominal pain, vomiting has been identified as an independent predictor of ovarian torsion, meaning its presence should raise suspicion even when the pain itself isn’t classic. Some people also develop a low-grade fever as the tissue becomes inflamed or starts to die.
If the ovary is intermittently twisting and untwisting, symptoms may come in episodes over days or even weeks before a final, sustained twist occurs. This pattern of recurring pelvic pain that resolves on its own is a red flag worth mentioning to your doctor, especially if you know you have an ovarian cyst.
How It’s Diagnosed
Ultrasound with Doppler imaging is the primary tool for evaluating suspected torsion. Doppler allows the sonographer to assess blood flow to the ovary. In one study of surgically confirmed torsion cases, about 72% showed no detectable arterial or venous blood flow on ultrasound. Abnormal blood flow is highly predictive of torsion and is one of the most useful findings on imaging.
Another characteristic ultrasound finding is an enlarged ovary studded with small follicles (roughly 8 to 12 mm each) around its outer edge. This pattern appears in up to 74% of torsion cases and results from fluid leaking into the follicles as blood backs up in the congested ovary. A visibly enlarged, edematous ovary on one side, with a normal-looking ovary on the other, is a strong clue.
That said, normal-looking blood flow on ultrasound does not rule out torsion. The ovary may be only partially twisted, or intermittent torsion may allow some flow at the moment of the scan. When clinical suspicion is high, surgery to directly visualize the ovary is the definitive way to confirm or exclude the diagnosis.
Surgical Treatment
The only treatment for ovarian torsion is surgery, typically done laparoscopically through small abdominal incisions. The two options are detorsion (untwisting the ovary and leaving it in place) or removal of the ovary entirely.
Historically, surgeons removed the affected ovary almost reflexively, partly out of fear that untwisting it could send blood clots into the circulation, and partly because a dark, bruised-looking ovary was assumed to be dead tissue. Both of those fears have turned out to be largely unfounded. Research shows that even ovaries that appear black or blue during surgery, a sign of severe congestion, recover both their normal appearance and function once blood flow is restored. The dark color reflects blood pooling and swelling, not necessarily permanent tissue death. True necrosis and infection tend to develop only after roughly 36 hours or more of complete blood flow loss.
Because of this evidence, the strong trend in modern practice is toward detorsion whenever possible, preserving the ovary to maintain its hormonal and reproductive function. In one large study, over 91% of women who underwent surgery for torsion had their ovary preserved through detorsion rather than removed.
Fertility After Torsion
One of the most common concerns after ovarian torsion is whether it will affect your ability to have children. The evidence is reassuring. A study comparing women who had detorsion with those who had their ovary removed found no significant difference in live birth rates afterward: about 78% of women who had detorsion and 59% of women who had an ovary removed went on to have a live birth, with the difference not statistically significant. Rates of needing fertility treatment were also similar between the two groups, at around 4 to 6%.
The overall conclusion from this research is that surgically treated ovarian torsion does not appear to negatively affect fertility or the ability to carry a pregnancy to a live birth. Even losing one ovary entirely does not typically impair fertility, since the remaining ovary compensates by continuing to ovulate.
Why Speed Matters
Ovarian torsion is time-sensitive in a way that many other causes of pelvic pain are not. The longer the ovary goes without blood flow, the greater the chance of irreversible tissue damage. While ovaries can remain viable for up to about 24 hours of restricted blood flow, the window narrows quickly after that. Faster treatment also means a higher likelihood of saving the ovary through detorsion rather than needing removal. If you experience sudden, severe one-sided pelvic pain, especially with nausea or vomiting, treating it as urgent and heading to the emergency department gives you the best chance of preserving the ovary and avoiding complications.