In short
Most women with fibroids conceive and deliver without trouble. Position matters more than size: fibroids that distort the uterine cavity carry the clearest risks, while those on the outer wall usually do not.
Emergency if: Go to an emergency department or maternity assessment unit immediately for heavy vaginal bleeding in pregnancy, regular painful contractions or a leak of fluid before 37 weeks, constant severe abdominal pain with a hard tender uterus, fainting, or a noticeable reduction in your baby's movements.
On your report
Hemoglobin, Ferritin, AMH (Anti-Müllerian Hormone), FSH (Follicle-Stimulating Hormone)
On this page
01
Can You Get Pregnant With Fibroids?
Most women with fibroids do conceive. Reviews of fertility practice find fibroids in about 5 to 10 percent of people being investigated for infertility, and estimate that fibroids are the sole identifiable cause in only about 1 to 2.4 percent of those cases. The American Society for Reproductive Medicine puts it cautiously in its guideline, concluding that there is insufficient evidence to say that fibroids reduce the likelihood of achieving pregnancy.
Fibroids are also common in pregnancy itself. Prevalence in pregnancy is reported between 1.6 and 10.7 percent overall, rising with age to around 32 percent in women aged 35 to 42. Because fibroids become more common through the thirties and forties, and because more people are conceiving in those years, the two increasingly coexist without one having caused anything about the other. Coexistence is not the same as causation, and that is easy to lose sight of when a scan puts a name to something.
The practical consequence is that finding a fibroid during a fertility work-up does not close the investigation. It is one item on a list that still includes ovulation, tubal patency, sperm quality and age, and any of those can be the actual explanation. The question worth asking your clinician is not whether you have a fibroid but which type it is, how large it is, and whether it touches or distorts the cavity. Those answers, not the diagnosis itself, determine what happens next.
02
Which Fibroids Actually Affect Fertility?
The evidence is strongest and least ambiguous for submucosal fibroids that distort the cavity. Pooled data from assisted reproduction show a relative risk of about 0.3 for pregnancy and 0.28 for implantation compared with women who have infertility and no fibroids, with similar odds ratios of roughly 0.3 for both conception and delivery. These are the fibroids sitting where an embryo needs to implant.
Intramural fibroids sit in the middle of the evidence and in the middle of the wall. Analyses report odds ratios around 0.62 for implantation and 0.7 for delivery, and other datasets put conception at about 0.8 and delivery at 0.7. Miscarriage appears more common as well: the relative risk of spontaneous loss is about 1.68 in women with fibroids of any location, with submucosal and intramural fibroids carrying the higher rates and subserosal ones showing no significant effect. The reviews suggest, rather than prove, that cavity distortion is what separates the intramural fibroids that matter from those that do not.
Subserosal fibroids, the ones bulging outward from the uterus, have a negligible measured impact on fertility with assisted reproduction, and that finding is consistent across the reviews. If a scan report describes a fibroid on the outer surface, or one hanging on a stalk, it is unlikely to be the reason conception is taking time. It may still cause pressure symptoms or pain worth treating in their own right, but that is a separate conversation from the fertility one.
03
When Is Removing a Fibroid Before Trying Worth It?
For submucosal fibroids, the ASRM guideline finds fair evidence that hysteroscopic myomectomy improves clinical pregnancy rates, and grades that recommendation accordingly. It is more reserved about miscarriage, concluding there is insufficient evidence that the same operation reduces the likelihood of early pregnancy loss. So the case for removing a fibroid from inside the cavity rests mainly on improving the chance of conceiving, not on preventing a loss once you have conceived. That is a narrower claim than the one people often carry into the appointment.
For fibroids in the wall that push into the cavity, described as intramural with a submucosal component, the guideline says myomectomy may be considered to improve pregnancy rates, and notes fair evidence that open or laparoscopic myomectomy for cavity-distorting fibroids improves pregnancy rates and reduces the risk of early pregnancy loss. That is the clearest surgical indication in the fertility setting.
The guideline is equally clear about where surgery is not indicated. Myomectomy is generally not advised to improve pregnancy outcomes in women who have no symptoms and fibroids that do not distort the cavity, and there is insufficient evidence that removing subserosal fibroids improves fertility. Since surgery carries its own risks, a recovery period and a possible effect on how you will deliver, that distinction is worth pressing on.
04
What Actually Happens During Pregnancy?
The reassuring headline holds: most women with uterine fibroids deliver vaginally without complications. Reviews estimate that between 10 and 30 percent of pregnant women with fibroids experience some complication during pregnancy, labor or the weeks afterward, which means the majority do not. Complications cluster in identifiable situations rather than being spread evenly, and knowing whether you are in one of those groups is more useful than knowing the overall figure.
Risk concentrates around multiple fibroids, fibroids larger than five centimeters, and fibroids sitting in the lower part of the uterus where the baby has to pass. Pooled odds ratios from the obstetric literature show preterm birth at about 1.5, malpresentation at 2.65, placental abruption at 2.63, placenta previa at 2.21, cesarean birth at 2.60 and postpartum hemorrhage at 2.95. These are relative figures, and a doubling of the odds of an uncommon event still leaves it uncommon.
Growth during pregnancy is usually limited and front-loaded. Up to about 71 percent of fibroids enlarge between the first and second trimesters, with smaller fibroids showing the most growth potential, and they typically stabilize through the second and third trimesters before reducing in the weeks after birth. A fibroid that grew early is behaving as expected rather than misbehaving, and the fact that it enlarged in the first trimester says little on its own about how the rest of the pregnancy will go.
05
Why Does a Fibroid Hurt in Pregnancy?
The commonest fibroid complication in pregnancy is red degeneration, reported in around 8 percent of women with fibroids. Veins feeding the fibroid clot, part of it loses its blood supply and dies, and the result is sudden abdominal pain, tenderness over the fibroid, sometimes fever and nausea. It usually happens as the fibroid outgrows what its vessels can supply during the fastest-growing early weeks.
Management is conservative and usually effective. Rest, fluids, antiemetics and pain relief carry most people through. Non-steroidal anti-inflammatory drugs are used only briefly and are avoided from around twenty weeks onward because of their effects on the fetal circulation and on amniotic fluid, so your team will advise what suits your stage. Pain generally settles over days rather than hours. The fibroid itself does not need to be removed, though surgery is considered in the uncommon case where symptoms do not settle on conservative treatment after a few days.
The catch is that the same picture has other causes, and one of them changes the plan completely. Torsion of a pedunculated fibroid produces very similar symptoms, and telling the two apart matters because red degeneration is managed conservatively while torsion needs surgery. Placental abruption also has to be excluded. That is precisely why new severe abdominal pain in pregnancy is a call-today situation and not something to work out at home, even when you already know a fibroid is there and even when the pain sits exactly where you would expect it to.
06
How Are Fibroids Monitored in Pregnancy?
Ultrasound is the most suitable method for the initial assessment, and the first trimester is the best window for it. Early on, the number, size and location of each fibroid can be mapped accurately while the uterus is still small. Later, a growing uterus and a baby in the way make the same measurements considerably harder and less reliable, which is why a fibroid that seems to change size on a third-trimester scan should be interpreted with caution.
Once that map exists, reviews suggest monthly ultrasound checks through the pregnancy for women with significant fibroids, watching size and position over time rather than reacting to each individual measurement. MRI has better sensitivity and is held in reserve for complex cases where ultrasound cannot answer the question, such as distinguishing a fibroid from another kind of pelvic mass, or working out exactly where a large fibroid sits in relation to the lower segment.
What the monitoring is really tracking is geography. A fibroid in the lower uterine segment can obstruct the birth canal or sit across the line of a cesarean incision, and a fibroid lying under the placenta is relevant to abruption risk. Knowing this by the middle of pregnancy gives the obstetric team time to plan the birth rather than improvise on the day.
07
Can Fibroids Be Removed During a Cesarean?
Traditional teaching discouraged it, and for a concrete reason: removing a fibroid from a uterus supplied by pregnancy blood flow risks heavy bleeding, which could force an unwanted hysterectomy and bring severe anemia, transfusion or infection with it. Generations of obstetricians were taught to leave fibroids alone at cesarean and deal with them later, once the uterus had returned to its usual size and blood supply.
More recent evidence complicates that rule without settling it. A 2017 meta-analysis found no increase in major hemorrhage, blood transfusion rate or postoperative fever when myomectomy was performed during a cesarean, only a longer operation, and observational data suggest it can be done without a high rate of life-threatening complications where the obstetrician has the expertise. A later pooled analysis is less reassuring, reporting a greater fall in hemoglobin, roughly a forty percent increase in blood transfusions and a longer hospital stay. All of it is observational rather than randomized, so it describes carefully chosen cases.
Which fibroid it is matters as much as who is operating. Subserosal and pedunculated fibroids, and single fibroids on the front wall or in the lower segment, are the ones most often removed safely, while intramural, multiple, deep, cornual and posterior wall fibroids carry more risk. Reviewers accordingly land in different places: one concludes that cesarean myomectomy should generally be avoided, another that surgeons should be cautious before advocating it as standard practice. It is a case-by-case decision, not a routine one, and worth raising well before the date.
08
How Long Should You Wait After a Myomectomy?
The advice you will most often hear is to wait three to six months, and studies of uterine healing after myomectomy generally show the scar consolidating within that window. It is worth knowing that this is convention supported by healing data rather than a proven threshold: a systematic review concluded that the data are insufficient to advise a minimum interval between myomectomy and conception to avoid uterine rupture. Your surgeon's number reflects the operation they actually performed.
There is an argument against waiting longer than necessary. Fibroids recur, with recurrence rates of roughly 34 to 41 percent reported over three years in some series and a wider range of about 15 to 51 percent up to five years across the literature, so a long delay can mean operating on the same uterus twice. That trade-off, alongside your age, is the conversation to have before you start trying.
How you deliver afterward depends on how deep the surgery went. Cesarean birth before labor starts, at about 36 to 37 weeks, is recommended after extensive or complicated myomectomy, which in practice means an operation that entered the cavity or removed a large fibroid through a thick myometrial incision. Less extensive, uncomplicated cases may allow a trial of labor with continuous monitoring, managed much like a vaginal birth after cesarean; reviewers judge the rupture risk after myomectomy, put at about 0.93 percent overall, not significantly greater than in that setting.
Fibroids in pregnancy: what to do and when
Routine — see a doctor
Before trying to conceive with known fibroids, book a gynecology appointment to establish the FIGO type and whether the cavity is distorted, and to check hemoglobin and iron stores. After a myomectomy, ask your surgeon specifically how long to wait and whether a planned cesarean will be recommended.
Same-day — call promptly
Contact your maternity team the same day for new abdominal pain over a known fibroid, a fever, persistent vomiting, or pain that stops you sleeping. Fever, spreading wound redness or foul-smelling discharge in the weeks after a myomectomy or cesarean also needs same-day review.
Emergency — act now
Go to an emergency department or maternity assessment unit immediately for heavy vaginal bleeding in pregnancy, regular painful contractions or a leak of fluid before 37 weeks, constant severe abdominal pain with a hard tender uterus, fainting, or a noticeable reduction in your baby's movements.
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Sources
- Fibroids and pregnancy — reviewpmc.ncbi.nlm.nih.gov
- Removal of myomas in asymptomatic patients to improve fertility and/or reduce miscarriage rate: a guideline (ASRM)asrm.org
- The impact and management of fibroids for fertility: an evidence-based approachpmc.ncbi.nlm.nih.gov
- Cesarean myomectomy: necessity or opportunity?pmc.ncbi.nlm.nih.gov
- Fibroids — NHSnhs.uk
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