If your fallopian tubes are blocked, the egg doesn’t reach the uterus. Instead, it stays in or near the tube, drifts into the pelvic cavity, and is quietly reabsorbed by your body. This happens without pain, without symptoms, and without any disruption to your menstrual cycle. Your body treats the unfertilized egg like any other cellular debris and breaks it down within hours to days.
Understanding what happens to the egg is really a starting point for a bigger set of questions: why tubes get blocked, whether you’d even know, and what your options are if you’re trying to conceive.
What Physically Happens to the Egg
Each month, one of your ovaries releases an egg. Normally, the fringed, fingerlike ends of the fallopian tube sweep the egg inside and guide it toward the uterus over the course of several days. When a tube is blocked, this journey is interrupted. Where the egg ends up depends on the location of the blockage.
If the blockage is at the far end of the tube (closest to the ovary), the egg may never enter the tube at all. It simply floats into the open space of your pelvic cavity. If the blockage is somewhere along the middle or near the uterus, the egg may enter the tube but get stuck partway through.
Either way, the egg doesn’t survive long. An unfertilized human egg is viable for roughly 12 to 24 hours. After that, it begins to break down. Your immune system finishes the job. Specialized immune cells called macrophages, which line the pelvic cavity, are built to engulf dead cells and clear cellular debris. They do this constantly, cleaning up not just stray eggs but old blood cells, tissue fragments, and other microscopic material. The egg is absorbed so efficiently that you won’t feel anything happening.
Your Period Still Comes Normally
One of the most common misconceptions is that blocked tubes would somehow stop your period or change your cycle. They don’t. Your menstrual cycle is controlled by hormones produced primarily by your brain and ovaries, not by your fallopian tubes. The tubes are a passageway, not a hormonal organ.
Studies comparing hormone levels in people with and without tubal blockages have found no consistent differences in luteinizing hormone, follicle-stimulating hormone, or estrogen levels. Your ovaries still release an egg on schedule each month, your uterine lining still builds up, and when pregnancy doesn’t occur, the lining sheds as a normal period. Blocked tubes are essentially invisible to your hormonal system.
Why Fallopian Tubes Get Blocked
Tubal blockages account for 25% to 35% of female factor infertility, making them one of the most common structural causes of difficulty conceiving. More than half of those cases trace back to salpingitis, an infection of the tubes most often caused by pelvic inflammatory disease (PID). PID is usually the result of sexually transmitted infections like chlamydia or gonorrhea that travel upward from the cervix. Even mild infections that cause few symptoms can leave behind scar tissue that narrows or seals the tubes shut.
Endometriosis is another major cause. When tissue similar to the uterine lining grows outside the uterus, it triggers chronic inflammation in the pelvis. The body responds by producing scar tissue and adhesions, which can bind the tubes, kink them, or block their openings. Because the fallopian tubes sit directly in the peritoneal fluid that bathes the pelvic organs, they’re especially vulnerable to this inflammatory environment.
Other causes include previous pelvic or abdominal surgery (which can create adhesions), a ruptured appendix, and, less commonly, certain congenital differences in tubal anatomy.
How Blockages Are Detected
Most people with blocked tubes have no idea until they struggle to get pregnant. A specific type of blockage called hydrosalpinx, where fluid accumulates and swells the tube, rarely causes noticeable symptoms. When it does, the signs are subtle: mild pelvic pain that may worsen around your period, or an unusual sticky or discolored vaginal discharge. These symptoms overlap with many other conditions, so they’re easy to dismiss.
The standard diagnostic test is a hysterosalpingogram (HSG), an X-ray where dye is injected through the cervix. If the dye flows freely through both tubes and spills into the pelvic cavity, the tubes are open. If it stops or pools, there’s a blockage. Some providers use a saline ultrasound or laparoscopy (a small camera inserted through the abdomen) for a more detailed look.
Partial Blockages and Ectopic Pregnancy
Not all blockages are complete. A tube can be narrowed by scarring without being fully sealed. This creates a particularly risky situation if you’re trying to conceive, because sperm are small enough to navigate past partial obstructions that a fertilized egg cannot. The embryo can implant inside the tube itself, resulting in an ectopic pregnancy.
Ectopic pregnancies are medical emergencies. The tube cannot stretch to accommodate a growing embryo, and if left untreated, it can rupture. Anyone with known tubal damage who becomes pregnant should have early monitoring to confirm the pregnancy is located inside the uterus.
Fertility Options With Blocked Tubes
Blocked tubes prevent natural conception, but they don’t prevent pregnancy. The two main paths forward are surgical repair and IVF, and the right choice depends on your age, the location and severity of the blockage, and whether other fertility factors are involved.
Surgical Approaches
For blockages near the uterine end of the tube (proximal blockages), a procedure called tubal cannulation can sometimes thread a small catheter through the obstruction to reopen the passage. For blockages at the far end, surgeons can sometimes cut away damaged tissue and reconstruct the tube’s opening. Success varies widely depending on how much healthy tube remains and how extensive the scarring is.
When a tube is severely damaged and filled with fluid (hydrosalpinx), the standard recommendation before IVF is to either remove the tube entirely or clip it shut near the uterus. This prevents toxic fluid from leaking into the uterine cavity, where it can reduce implantation rates. Clinical data shows that both removal and clipping produce similar IVF outcomes in terms of clinical pregnancy rates, live birth rates, and miscarriage rates, so the choice often comes down to surgical factors and physician preference.
IVF Success Rates
IVF bypasses the tubes entirely. Eggs are retrieved directly from the ovaries, fertilized in a lab, and the resulting embryo is placed into the uterus. For people whose only fertility issue is tubal blockage, IVF outcomes are encouraging. Cumulative pregnancy rates climb significantly with repeated cycles: roughly 32% after one cycle, 59% after two, 70% after three, and 77% after four.
Age is the strongest predictor of success. Delivery rates per transfer cycle are around 48% for those under 30, dropping to 28% by ages 35 to 38, and falling to under 10% after age 41. Because fertility declines with time, many specialists recommend moving to IVF sooner rather than spending months or years on surgical repair, especially for people over 35.
When Only One Tube Is Blocked
If one tube is open and healthy, natural conception is still possible. You ovulate from alternating ovaries (though not in a perfectly predictable pattern), so roughly half the time, the egg will release on the side with the functioning tube. Many people with a single blocked tube conceive without any intervention, though it may take longer on average. Your provider may suggest monitored cycles or ovulation-tracking ultrasounds to time intercourse to months when the open side is ovulating.
If the blocked tube contains a hydrosalpinx, your provider may still recommend removing or clipping it even though the other side works. The inflammatory fluid can reduce fertility on its own by affecting the uterine environment.