Does Uterine Fibroids Affect IVF in China? Reproductive Doctor Explains Fibroid Assessment and Management

Opening: Doctor's Decision-Making Logic

In the reproductive clinic, we encounter patients consulting for IVF with fibroid reports almost every day. As a reproductive doctor, when I see the diagnosis of "uterine fibroids," my primary focus is not the fibroid itself, but three questions: Where is the fibroid located, how large is it, and does it affect the endometrium? These three questions directly determine the subsequent decision-making path — whether to proceed directly with the cycle, undergo surgery before IVF, or adjust the ovarian stimulation protocol before attempting. Below, I will break down this issue clearly from a clinical perspective.

I. Do Uterine Fibroids Actually Affect IVF?

Yes, they can, but the degree of impact depends entirely on the specific characteristics of the fibroid. Not all fibroids reduce IVF success rates. Clinically, about 40% to 60% of patients with fibroids can proceed directly to an IVF cycle without surgery. What truly requires priority treatment are those fibroids that alter the uterine cavity shape and affect endometrial receptivity. Reproductive centers in China commonly use a "location-size-type" three-dimensional assessment system to determine whether a fibroid requires intervention.

II. Why Do Fibroids Affect IVF Outcomes?

The impact of uterine fibroids on IVF is mainly through the following mechanisms:

• Altering Uterine Cavity Shape: Submucosal or large intramural fibroids can deform the uterine cavity, reducing the endometrial surface area, making it difficult for the embryo to find a suitable "implantation site."
• Affecting Endometrial Blood Flow: The resistance of uterine artery blood flow around the fibroid increases, leading to insufficient blood supply to the endometrium and decreased receptivity.
• Local Inflammatory Environment: Fibroid tissue secretes certain inflammatory factors (such as TGF-β, IL-6), altering the immune microenvironment of the endometrium, which is unfavorable for embryo implantation.
• Affecting Uterine Contractions: Large fibroids may cause abnormal uterine contractions, interfering with embryo positioning and adhesion.

It should be noted that these effects are not absolute. Many small fibroids or those in favorable locations do not trigger the above mechanisms, which is why a "one-size-fits-all" approach is not taken clinically.

III. How Does a Reproductive Doctor Assess a Patient with Fibroids?

In Chinese reproductive centers, the assessment process typically involves three steps:

Step 1: Precise Localization — Ultrasound + 3D Ultrasound

Standard ultrasound can only detect the presence of a fibroid but cannot accurately determine if it compresses the endometrium. We use 3D transvaginal ultrasound to observe the uterine cavity shape from the coronal plane and clarify the relationship between the fibroid and the endometrium. If a submucosal fibroid is suspected, a hysteroscopy is arranged — this is the gold standard for diagnosing submucosal fibroids.

Step 2: Measuring Size and Number

Fibroid diameter is an important reference indicator. For intramural fibroids, 4 cm is generally considered the clinical warning line. If it exceeds 4 cm and protrudes into the uterine cavity, surgery is recommended; if it is smaller than 4 cm and does not compress the endometrium, observation is possible. For multiple fibroids, the total burden must be considered; if the combined volume of several fibroids is large, comprehensive evaluation is needed.

Step 3: Assessing Patient Age and Ovarian Reserve

This point is often overlooked. For the same 4 cm intramural fibroid, a patient under 35 with normal ovarian function can undergo surgery first and then IVF; for a patient over 40 with low AMH, surgery might delay the window of ovarian function. Sometimes we recommend not treating the fibroid and proceeding directly with egg retrieval to accumulate embryos, or even attempting a transfer first to see the outcome. Age and ovarian reserve are crucial factors on the decision-making scale.

IV. The Most Easily Overlooked Details

In clinical practice, several details are easily missed by both patients and some doctors:

• Fibroid Growth Rate: If a fibroid grows from 3 cm to 5 cm within six months, even if it currently does not compress the endometrium, caution is needed. Fast-growing fibroids may be "active" and could enlarge further under estrogen stimulation during pregnancy, increasing the risk of pregnancy complications.
• Fibroid Location Classification (FIGO Staging): Submucosal fibroids are classified as Type 0 (completely in the uterine cavity), Type I (<50% intramural portion), and Type II (≥50% intramural portion). Types 0 and I have a significant impact on IVF, while Type II is relatively milder and sometimes allows for a trial of pregnancy without removal.
• Distance Between the Endometrium and the Fibroid: If an intramural fibroid is less than 5 mm from the endometrium, even if its diameter is small, it may affect local blood flow. This detail is often not included in many ultrasound reports and requires measurement by an experienced sonographer.
• Fibroid Calcification or Degeneration: Calcified fibroids are usually "quiet" and have less impact; however, red degeneration or infected fibroids can cause pelvic inflammation and require treatment.

V. The Most Common Pitfalls

VI. Actual Management Process in Chinese Reproductive Centers

Taking mainstream domestic reproductive centers as an example, the standardized treatment pathway for patients with uterine fibroids is as follows:

Note: The above is a general reference. The specific plan should be comprehensively formulated based on the patient's age, AMH, obstetric history, and symptoms (such as heavy menstruation, abdominal pain, etc.).

VII. Analysis of Three Real Scenarios

Scenario 1: 32 years old, submucosal fibroid (Type I) 2.5 cm, heavy menstruation, trying to conceive for 2 years without success.
Patient's AMH is 3.8 ng/mL, normal ovarian reserve. Management plan: Perform hysteroscopic myomectomy, allow 3 months for endometrial recovery, then proceed with ovarian stimulation for IVF. Successful pregnancy after one transfer. The key in this case: The impact of submucosal fibroids on implantation is clear, and the patient is young, allowing time for surgery first.

Scenario 2: 39 years old, intramural fibroid 5 cm (protruding into the uterine cavity), AMH 0.9 ng/mL.
The patient is of advanced age with diminished ovarian reserve. If surgery is performed first, waiting 6-12 months could further compromise ovarian function. Final decision: First, retrieve eggs to accumulate embryos, freeze 2 blastocysts, then undergo fibroid surgery. After 6 months of recovery, transfer the frozen embryos. This preserves the embryos while improving the implantation environment. The patient is currently successfully pregnant.

Scenario 3: 41 years old, subserosal fibroid 6 cm, no symptoms, AMH 0.6 ng/mL.
Subserosal fibroids do not affect the uterine cavity, so proceed directly to the IVF cycle. Two egg retrievals yielded 3 blastocysts, but transfer did not result in pregnancy. Analysis of failure cause: Unrelated to the fibroid; the main issue is the high rate of embryonic aneuploidy due to advanced age. Recommendation: Perform PGT-A screening before the next transfer. This case illustrates: Do not attribute all failures to fibroids; conduct a comprehensive analysis.

VIII. Frequently Asked Questions

Q1: How long after fibroid surgery can I have a transfer?

For hysteroscopic submucosal fibroid resection: generally 3 months post-op, after the endometrium has healed, you can start the cycle. For laparoscopic or open intramural myomectomy: 6-12 months post-op, requiring ultrasound confirmation of good uterine scar healing. The specific time depends on the surgeon's assessment.

Q2: Will fibroids grow during pregnancy?

Yes. Estrogen levels rise during pregnancy, and fibroids may enlarge by 20% to 30%, especially those >5 cm in diameter. Regular ultrasound monitoring during pregnancy is needed. If symptoms like abdominal pain or fever occur, seek medical attention promptly. However, most fibroids are safe during pregnancy.

Q3: My fibroid is in a bad location, but I don't want surgery. Can I go directly to IVF?

You can try, but be mentally prepared. For submucosal fibroids or intramural fibroids compressing the endometrium, the implantation rate may decrease by 30% to 50%, and the miscarriage rate may also increase. If you have a good number of high-quality embryos, it might be worth a try; if embryos are precious, it is recommended to treat the fibroid first.

Q4: What is the IVF success rate with uterine fibroids?

There is no single answer to this question, as the type, size, and location of the fibroid, as well as the patient's age, ovarian function, and embryo quality, all influence the success rate. Based on clinical data: After treatment for submucosal fibroids, the live birth rate can approach that of age-matched women without fibroids; for intramural fibroids <4 cm not compressing the endometrium, the success rate is not significantly different from women without fibroids; for large untreated fibroids (>5 cm), the live birth rate may decrease by 15% to 25%. Individualized assessment is necessary.