Repeated ectopic pregnancies usually come down to an underlying problem with the fallopian tubes, whether from past infections, structural abnormalities, or damage from previous treatments. After one ectopic pregnancy, the risk of it happening again ranges from 10% to 27%. After two, that risk jumps dramatically: women with two prior ectopic pregnancies have roughly a tenfold increased risk of yet another one compared to women with just one prior occurrence.
How Tubal Damage Traps an Embryo
Your fallopian tubes aren’t just hollow passageways. Their inner lining is covered in tiny hair-like structures that beat in coordinated waves, pushing a fertilized egg toward the uterus over the course of several days. The tube walls also contract rhythmically to help move things along. When either of these transport systems is compromised, an embryo can slow down, get stuck, and implant in the tube instead of the uterus.
The damage that causes this is often invisible from the outside. Sexually transmitted infections, particularly chlamydia and gonorrhea, are the most common culprits. Chlamydia has a direct toxic effect on the cells lining the fallopian tube, stripping away the tiny structures that move the egg and destroying cell connections. The body’s inflammatory response to infection then compounds the problem, releasing chemicals that cause scarring and permanent tissue damage. Certain strains of chlamydia are especially destructive and can severely reduce the tube’s ability to move anything through it. Gonorrhea works similarly, producing toxins that slow the beating of those inner hair-like cells. The critical point is that this damage is cumulative and permanent. Even a single infection treated with antibiotics can leave behind scarring you’d never know about until a pregnancy goes wrong.
A Structural Condition Many Women Don’t Know About
A condition called salpingitis isthmica nodosa causes nodular swelling in the narrowest part of the fallopian tube, where the inner passage is only 1 to 2 millimeters wide. Thickened tissue and small pouches form in the tube wall, creating physical blockages that an embryo can’t easily pass through. This condition is found in about 10% of women with tubal ectopic pregnancies overall, but that number rises to nearly 46% when the ectopic specifically lodges in the narrow section of the tube.
If you’ve had ectopic pregnancies that keep occurring in the same part of the tube, this condition may be the reason. It can also lead to a buildup of fluid in the tube (hydrosalpinx), further impairing function. Attempts to clear blockages caused by this condition have a failure rate of 93%, which is why it’s a particularly stubborn cause of recurrent ectopics.
How Smoking Slows Embryo Transport
Nicotine directly interferes with the muscle contractions that move an embryo through the fallopian tube. Animal studies show that exposure to cigarette smoke, at levels producing the same blood markers seen in human smokers, significantly slows embryo transport by inhibiting smooth muscle contraction in the tube. Nicotine also reduces blood flow to the fallopian tubes, which further weakens contractions and delays the embryo’s journey. Even secondhand smoke exposure produces measurable effects on tube function. If you smoke and have had recurrent ectopic pregnancies, this is one of the few modifiable risk factors you can directly address.
Hormonal Receptors That Don’t Work Properly
The fallopian tubes rely on signals from estrogen and progesterone to regulate their contractions and the beating of their inner lining. In women with ectopic pregnancies, researchers have found that the tubes have significantly reduced levels of progesterone receptors and undetectable levels of certain estrogen receptors. This means the tube can’t properly respond to the hormonal shifts that normally coordinate embryo transport. Without those signals, the timing of contractions and cell activity goes off, and the embryo doesn’t reach the uterus on schedule. Whether this receptor problem is a cause or a consequence of the ectopic is still being worked out, but it helps explain why some women’s tubes simply don’t move embryos the way they should.
How Previous Treatment Affects Your Next Pregnancy
The way your earlier ectopic pregnancies were treated plays a real role in what happens next. When researchers compared recurrence rates across treatment types, the numbers broke down clearly. Tube-conserving surgery (where the tube is opened and the pregnancy removed but the tube is kept) carried a 15.4% recurrence rate. Full tube removal brought that down to 9.8%. Medication treatment had the lowest recurrence rate at 8%.
This doesn’t necessarily mean keeping your tube was the wrong choice. Among women who tried to conceive afterward, 61.4% achieved a healthy uterine pregnancy after tube-conserving surgery, compared to only 38.1% after full tube removal. Medication treatment landed in between at 54%. So keeping a damaged tube gives you a better shot at a future pregnancy in the uterus, but it also means you’re more likely to have another ectopic in that same tube, especially if the tube was already diseased.
As for whether medication affects your fertility compared to surgery, the outcomes are essentially the same. In a comparison of 130 patients in each group, 68.5% of the medication group and 73% of the surgical group went on to have a healthy uterine pregnancy, a difference that was not statistically meaningful.
IVF Doesn’t Eliminate the Risk
Many women with a history of ectopic pregnancies turn to IVF, assuming that placing an embryo directly into the uterus bypasses the problem entirely. It reduces the risk, but it doesn’t eliminate it. Ectopic pregnancy rates following IVF are two to three times higher than the 1-2% rate seen in natural conception. Even with a single embryo transfer, IVF carries more than six times the relative risk of ectopic pregnancy compared to conceiving naturally. For women whose infertility is specifically caused by tubal problems, the ectopic rate after IVF can reach 11%.
This happens for a few reasons. The embryo can still migrate from the uterus into the tube after transfer, pushed by the fluid used during the procedure or by normal uterine contractions. The hormonal medications used to stimulate egg production can also alter the lining of both the uterus and the tubes, disrupting the normal signals that guide implantation. If the tubes are damaged, they may not be able to push a wayward embryo back toward the uterus.
Testing That Can Identify the Problem
If you’ve had more than one ectopic pregnancy, imaging and diagnostic testing can help pinpoint what’s going on with your tubes. A hysterosalpingogram (HSG), where dye is flushed through the uterus and tubes while X-rays are taken, can reveal blockages, structural abnormalities, and whether one or both tubes are affected. Women with normal HSG results have significantly higher rates of successful pregnancy afterward, while those with abnormalities on both sides see their fertility rate drop to about a third of normal.
Early monitoring in subsequent pregnancies is also critical. The standard approach combines blood hormone level tracking with transvaginal ultrasound. If your initial blood levels are below a certain threshold, a repeat test 48 hours later can show whether the pregnancy is progressing normally based on how quickly those levels rise. Once levels are high enough, an ultrasound can confirm whether the pregnancy is in the uterus. Using both tests together, rather than relying on either one alone, provides the most reliable detection, with specificity reaching 100% for identifying an ectopic location.
What You Can Control
Some causes of recurrent ectopic pregnancy, like structural tube abnormalities or old infection damage, can’t be reversed. But a few factors are within your control. Quitting smoking directly improves fallopian tube function. Prompt treatment of any sexually transmitted infection reduces the chance of additional scarring. If you’re planning another pregnancy, early monitoring starting from the first positive test gives you the best chance of catching an ectopic before it becomes dangerous, and it gives your care team the widest range of treatment options.
For women with known bilateral tube damage or repeated ectopics despite treatment, the conversation with a reproductive specialist typically moves toward IVF with careful attention to transfer technique, or in some cases, removal of severely damaged tubes before IVF to improve implantation rates in the uterus. The right path depends on how much tube function remains and whether one or both sides are affected.