A 2024 study combined the results of 14 studies analyzing how hysteroscopy impacts IVF success, finding improvements in live birth rate, pregnancy rate and no change in miscarriage rate.
Hysteroscopy is an imaging technique that directly inspects the uterine cavity using a small camera inserted through the cervix. It can be used to diagnose and treat polyps, fibroids and other uterine abnormalities.
Other imaging techniques, like ultrasound and saline infusions, might miss some of the abnormalities that can be detected by hysteroscopy.
This post is a summary of a study by Wang et al. (2024), who performed a meta-analysis and combined the results of 14 randomized controlled trials (RCTs) on the effectiveness of hysteroscopy in improving outcomes for infertility patients. Patients had hysteroscopy before their IVF procedure, to diagnose and treat/operate on uterine abnormalities that were found.
🔗 Original studies are referenced in this post or within the linked Remembryo posts.
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Study details
- The 14 studies included patients who had their first IVF attempt or a history of one or more unsuccessful attempts.
- The patients had a normal transvaginal ultrasound, HSG or SIS / GIS before hysteroscopy and IVF.
- What did the hysteroscopy find? It commonly showed that many women had normal uterine conditions, with the most frequently observed uterine abnormalities as endometrial polyps and various types of adhesions. Other less common findings included cervical stenosis, endometritis, uterine abnormalities like septums and myomas, and some cases of endometrial hyperplasia and fibroids.
- The timing of hysteroscopy in the studies varied widely, ranging from a single month to several months before IVF, immediately before IVF, or several months after failed IVF cycles. The authors note that most studies recommend performing hysteroscopy in the early to mid-follicular phase after menstruation, as this timing offers a clear view and simpler procedure due to a thinner endometrium.
Increase in live birth rate with hysteroscopy
Live birth rate: Based on 5 studies, hysteroscopy before IVF increased the chance of live birth by 1.30 times vs patients without hysteroscopy (41.2% vs 33.9%, risk ratio [95% CI]: 1.30 [1.04-1.64], 2277 participants, I2= 71%). This was based on moderate quality of evidence.
These 5 studies included patients doing their first IVF cycle (3 studies) and patients with a history of unsuccessful IVF cycles (2 studies). When they looked at these groups separately, they found no statistical difference in live birth rates. This sometimes happens in meta-analyses: the individual groups aren’t statistically significant but the overall result is significant when all studies are combined and the dataset is larger.
The overall message here is that live birth rates increased with hysteroscopy across the general population included in these studies.
Hysteroscopy increases chance of pregnancy, no effect on miscarriage rates
Pregnancy rate: Based on 14 studies, hysteroscopy increased the chance of pregnancy 1.59 times vs patients without hysteroscopy (48.1% vs 34.2%, risk ratio [95% CI]: 1.59 [1.34-1.89], 3985 participants, I2= 75%). This is based on low quality of evidence.
- Pregnancy rate for patients doing their first IVF cycle: Based on 9 studies, hysteroscopy increased the chance of pregnancy by 1.61 times vs those without hysteroscopy (54.6% vs 38.6%, risk ratio [95% CI]: 1.61 [1.27-2.04], 2157 participants, I2= 76%).
- Pregnancy rate for patients with a history of 1 or more unsuccessful IVF cycles: Based on 5 studies, hysteroscopy increased the chance of pregnancy by 1.62 times vs those without hysteroscopy (40.4% vs 29.1%, risk ratio [95% CI]: 1.62 [1.18-2.24], 1828 participants, I2= 79%).
Miscarriage rate: Based on 8 studies, hysteroscopy had no impact on miscarriage rates overall, and in patients doing their first IVF cycles or with a history of unsuccessful cycles.
Complications after hysteroscopy are rare
Based on 4 studies, only one found a complication in patients who had a hysteroscopy, resulting in a single patient developing endometritis. The authors note that this was an infection due to hysteroscopy, and that the overall chance of infection is about 0.01% to 0.2%.
Conclusions
Overall, this meta-analysis found that hysteroscopy resulted in a higher chance of live birth and clinical pregnancy rate, with no change in miscarriage rate.
For women either having their first IVF cycle, or those doing another cycle after an unsuccessful one, hysteroscopy improved the chance of pregnancy.
Among the studies reporting complications due to hysteroscopy, there was only a single case reported. This shows that the procedure is generally safe.
The authors note several limitations of this research, mainly relating to the large amount of variability across the studies (heterogeneity), small sample sizes and biases. While the included studies were RCTs, the research quality was “generally poor,” with many studies lacking trial registration and blinding. After a quick glance, two of the studies they included appear higher quality, which found no change in live birth rate with hysteroscopy.
The authors stress that higher quality RCTs are needed to draw conclusions.
Other meta-analyses have been done on the topic, finding an increase in live birth and pregnancy rates with hysteroscopy based on low to moderate quality data.
Related studies
To learn more about this topic, you can check out a number of studies referenced in this study below, or meta-analyses I found on the topic (10 links):
Reference
About Embryoman
Embryoman (Sean Lauber) is a former embryologist and the founder of Remembryo, an IVF research and fertility education website. After working in an IVF lab in the US, he returned to Canada and now focuses on making fertility research more accessible. He holds a Master’s in Immunology and launched Remembryo in 2018 to help patients and professionals make sense of IVF research. Sean shares weekly study updates on Facebook, Instagram, and Reddit regularly. He also answers questions on Reddit or in his private Facebook group.
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