Your appendix stays in the lower right side of your abdomen for most of pregnancy, but the growing uterus can push it upward by a few centimeters as you approach your due date. The classic location, known as McBurney’s point (roughly a third of the way between your hip bone and belly button on the right side), remains accurate for the majority of pregnant women. But understanding how much and when it shifts matters, because appendicitis is the most common surgical emergency during pregnancy, occurring in roughly 1 in every 200 to 1,700 pregnancies.
How Far the Appendix Actually Moves
For decades, medical textbooks taught that the appendix migrates dramatically upward during pregnancy, rotating toward the ribs as the uterus expands. More recent research paints a less dramatic picture. In studies tracking appendix position across gestational ages, the average upward displacement was about 3 to 4 centimeters from its normal resting spot. The maximum recorded shift was 4.5 centimeters, which is less than two inches.
Among women at 39 to 40 weeks of gestation, only about 12.5% had an appendix that had migrated noticeably above its usual position. The rest still had the appendix sitting in its normal anatomical location. One patient at 38 weeks did have the appendix reach all the way up to the right upper abdomen, near the rib cage, but this was an outlier rather than the norm. In women past 41 weeks, none showed significant upward displacement at all.
So while the appendix can shift, the idea that it reliably ends up under your ribs by the third trimester is outdated. For most pregnant women, even late in pregnancy, the appendix is still in the lower right quadrant of the abdomen.
Where Appendicitis Pain Shows Up During Pregnancy
This is the question behind the question for most people searching this topic. If the appendix moves, does that change where you’d feel pain? The short answer: not as much as you might think. About 70 to 80% of pregnant women with confirmed appendicitis still feel pain in the right lower quadrant, the same place you’d expect it outside of pregnancy. Only about 7% report pain in the right upper quadrant, near the ribs.
That said, diagnosing appendicitis during pregnancy is genuinely harder, and not just because of the appendix’s position. Normal pregnancy symptoms overlap with early appendicitis symptoms in frustrating ways. Nausea, vomiting, and mild abdominal discomfort are everyday parts of pregnancy for many women. Round ligament pain, which causes sharp or aching sensations in the lower abdomen, is another common source of right-sided discomfort that has nothing to do with the appendix. Other conditions that can mimic appendicitis include ovarian cysts that rupture or twist, kidney stones, gallstones, and kidney infections.
The distinguishing features of appendicitis tend to be pain that starts near the belly button and migrates to the right side, pain that worsens steadily over 12 to 24 hours rather than coming and going, and pain that gets worse with movement or coughing. If you’re pregnant and experiencing persistent, worsening right-sided abdominal pain, especially with fever, that combination warrants urgent evaluation.
Why Timing Matters So Much
Appendicitis during pregnancy peaks in the second trimester. The biggest risk isn’t the appendicitis itself but what happens if it’s caught late. When the appendix perforates (bursts), the complication rate jumps from about 17% to 52%. The time between when symptoms start and when surgery happens is one of the strongest predictors of preterm labor. Fetal mortality in cases that reach surgery sits around 8%, and perforation is the single strongest predictor of serious complications for the mother.
The delay problem cuts both ways. Pregnant women and their providers sometimes attribute abdominal pain to normal pregnancy discomfort, which pushes back the timeline for diagnosis. Imaging can also be trickier. Ultrasound is the first-line tool, since it’s safe for the baby, but it doesn’t always give a clear view of the appendix during pregnancy. MRI is the next step and is considered safe, with no radiation exposure.
What Surgery Looks Like During Pregnancy
If appendicitis is confirmed, surgery is the treatment regardless of trimester. Waiting and relying on antibiotics alone carries too much perforation risk. Both laparoscopic (keyhole) and open surgery are considered safe during pregnancy, but the data favors laparoscopic when it’s available.
A large systematic review comparing the two approaches found that laparoscopic surgery had a fetal loss rate of 2.4% compared to 2.6% for open surgery, and a preterm delivery rate of 9.8% versus 10.7%. The difference in preterm delivery was statistically significant, meaning it wasn’t just due to chance. Laparoscopic surgery also comes with shorter hospital stays, smaller incisions, and lower wound infection rates.
One unexpected finding from recent research: the surgery itself, not the inflamed appendix, appears to be the main driver of preterm birth risk. Women who had appendectomies but turned out to have a normal appendix (a “negative appendectomy”) actually had a higher rate of preterm delivery (20.5%) than women whose appendix was genuinely inflamed (9.2%). The physical stress of surgery on the uterus seems to be what triggers early contractions. This is why accurate diagnosis before operating is so important, and why imaging with ultrasound or MRI plays such a critical role.
What to Pay Attention To
The practical takeaway is straightforward. Your appendix is almost certainly still in the lower right side of your abdomen, even in late pregnancy. It may have shifted upward slightly, but for most women, the shift is modest. If you develop persistent pain on the right side of your abdomen that gets worse over hours, don’t write it off as round ligament pain or a normal pregnancy ache, particularly if it comes with nausea that feels different from your usual morning sickness, loss of appetite, or fever. The earlier appendicitis is caught during pregnancy, the better the outcomes for both you and the baby.