Ovarian torsion happens when an ovary twists around the ligaments that hold it in place, cutting off its own blood supply. The twisting can be partial or complete, sometimes rotating more than once. Without treatment, the loss of blood flow leads to tissue death, making this a surgical emergency that requires quick recognition.
The Anatomy That Allows Twisting
The ovaries aren’t rigidly fixed in the pelvis. Each one hangs from two ligaments: the suspensory ligament, which connects the ovary to the pelvic sidewall and carries the main blood vessels, and the utero-ovarian ligament, which connects it to the uterus. These two attachment points give the ovary enough mobility to shift position slightly, sitting to the side of or behind the uterus depending on body position and surrounding structures.
That mobility is also the vulnerability. When something causes the ovary to rotate on these ligaments, the blood vessels running through them get twisted and compressed. In some cases, the fallopian tube twists along with the ovary. Surgeons have documented ovaries twisted as far as 540 degrees, which is one and a half full rotations.
How Blood Flow Gets Cut Off
The damage from torsion follows a predictable sequence. Because veins and lymphatic channels have thinner, more flexible walls than arteries, they get compressed first. This traps blood and fluid inside the ovary, causing it to swell. The swelling then makes the situation worse, because a larger, heavier ovary is more likely to stay twisted or twist further.
If the torsion continues, arterial flow eventually gets blocked too. At that point, no fresh blood reaches the ovarian tissue. Without oxygen, the tissue begins to die. The progression moves from swelling to blood clots forming inside the ovary, then to tissue death and, if left long enough, complete infarction where the entire ovary is lost.
What Makes an Ovary More Likely to Twist
Anything that changes the size or weight of the ovary increases the risk. Cysts and masses are the most common culprit. The risk rises significantly once a cyst or growth reaches about 5 centimeters (roughly 2 inches) across, because the added weight creates more momentum when the body moves. Benign tumors called dermoid cysts are particularly associated with torsion because they tend to be heavy relative to their size.
But a mass isn’t always required. In children and adolescents, 40 to 50 percent of torsion cases involve completely normal ovaries. One Italian review of 127 pediatric cases found that 23.3 percent occurred in normal ovaries with no cyst or lesion at all. Longer ligaments or a naturally more mobile ovary may explain why some girls and young women are vulnerable without any underlying abnormality.
Fertility Treatments and Pregnancy
Ovarian stimulation during fertility treatments is a well-known trigger. Medications used to induce ovulation can cause the ovaries to enlarge dramatically, a condition called ovarian hyperstimulation syndrome. In pregnant women who develop this syndrome, the estimated incidence of torsion ranges from 6 to 16 percent.
Pregnancy itself is a risk factor. About 13.7 percent of torsion cases occur in pregnant patients, with the highest risk during the first trimester and early second trimester. During this window, the corpus luteum (the structure that forms after an egg is released) can enlarge the ovary, and the uterus is growing rapidly, shifting pelvic anatomy. By the third trimester, the uterus is large enough that there’s less room for the ovary to rotate freely, so the risk drops.
What Torsion Feels Like
The hallmark symptom is sudden, severe pain on one side of the lower abdomen or pelvis. It often comes on during physical activity or a sudden change in position. Nausea and vomiting are common, sometimes intense enough that the pain gets mistaken for a stomach problem. Some people experience pain that comes and goes if the ovary twists and partially untwists on its own, which can make the diagnosis harder because the symptoms seem to improve temporarily.
The pain doesn’t respond well to typical remedies. It’s different from menstrual cramps in that it’s usually one-sided, more acute in onset, and accompanied by that pronounced nausea. Fever can develop later if the tissue has already started to die.
How Torsion Is Diagnosed
Ultrasound is the primary tool. Doctors look for several signs: an enlarged, swollen ovary, fluid in the pelvis, and reduced or absent blood flow on Doppler imaging. One of the more specific findings is called the whirlpool sign, which shows the twisted pedicle (the stalk of ligament and vessels) spiraling on itself. A meta-analysis of six studies found the whirlpool sign has 65 percent sensitivity and 91 percent specificity, meaning it’s not always present but is highly reliable when it does appear.
No single ultrasound finding is enough to confirm or rule out torsion on its own. Reduced blood flow on Doppler is 95 percent specific but only catches about half of cases. This is partly because arterial flow can persist even when venous drainage is already compromised. A normal-looking ultrasound doesn’t guarantee the ovary isn’t twisted, which is why clinical suspicion based on symptoms remains important.
What Happens During Surgery
Surgery is the only treatment. The procedure is almost always done laparoscopically, through small incisions, and the first goal is to untwist the ovary and restore blood flow. Surgeons then watch the tissue to see if the color improves, which signals that the ovary may recover.
Saving the ovary is possible but not guaranteed. In a five-year review of 81 torsion cases, the ovary was successfully salvaged 43.2 percent of the time. The remaining 56.8 percent required removal. Interestingly, appearance during surgery doesn’t always predict what’s happening inside. In that same study, five patients whose ovaries still looked dark and damaged after untwisting turned out to have minimal or no tissue death when examined under a microscope. This is why many surgeons now lean toward trying to save the ovary even when it looks concerning, rather than removing it immediately.
Three patients who had their ovaries removed showed no evidence of tissue death at all on pathology, underscoring how difficult it can be to judge viability in real time. The trend in surgical practice has shifted toward preserving the ovary when possible, especially in younger patients who want to maintain fertility.
Recovery and Long-Term Outlook
If the ovary is saved, recovery from laparoscopic surgery typically takes one to two weeks. Most people return to normal activities within that window. The ovary’s ability to function afterward depends on how long blood flow was interrupted and how much tissue was damaged. Many salvaged ovaries resume producing hormones and releasing eggs normally.
Torsion can recur, particularly if the underlying cause (like a tendency to form large cysts) isn’t addressed. In some cases, surgeons will stitch the ovary to the pelvic wall to prevent future twisting, though this isn’t done routinely. If the ovary had to be removed, the remaining ovary typically compensates, and most people maintain normal hormone levels and fertility with one functioning ovary.