In a reproductive‑age woman with mild adenomyosis undergoing IVF embryo transfer, can a uterine relaxant be given beforehand?

Uterine Relaxants Before Embryo Transfer in Mild Adenomyosis

There is no guideline or high-quality evidence supporting the use of uterine relaxants before embryo transfer in patients with mild adenomyosis, and this intervention should not be routinely employed.

Evidence-Based Management Framework

Primary Treatment Approach for Adenomyosis and IVF

The available evidence does not address uterine relaxants specifically, but provides clear guidance on optimizing embryo transfer outcomes in adenomyosis patients:

• GnRH agonist pre-treatment is the evidence-based intervention that improves implantation and pregnancy rates in adenomyosis patients undergoing IVF, not uterine relaxants at the time of transfer 1, 2.

• A long GnRH agonist protocol before embryo transfer improves implantation rates in patients with adenomyosis by suppressing the disease activity and improving endometrial receptivity 1, 2.

• Pre-treatment with GnRH agonists for deferred (frozen) embryo transfer appears to improve pregnancy rates specifically in adenomyosis patients 1.

Critical Transfer Protocol Regardless of Adenomyosis Status

Single embryo transfer (SET) must be performed in all IVF cycles, including in patients with mild adenomyosis 3, 4.

• The decision to transfer embryos should not be based on endometrial characteristics, including the presence of mild adenomyosis 3.

• ESHRE provides a strong recommendation that endometrial characteristics must not determine whether to perform single versus double embryo transfer in frozen embryo transfer cycles 3, 4.

• The focus must remain on preventing multiple pregnancy complications, which would be particularly problematic in a uterus with adenomyosis 4.

Why Uterine Relaxants Are Not Standard Practice

The pathophysiology of adenomyosis-related infertility involves:

• Abnormal endometrial molecular expressions that impair implantation 2
• Altered sex steroid and pituitary hormone responses 2
• Increased inflammatory factors and immune dysregulation 2
• Reduced endometrial receptivity and altered adhesion molecule expression 2

None of these mechanisms are addressed by acute uterine relaxation at the time of transfer. The evidence points to systemic hormonal suppression (GnRH agonists) as the intervention that modifies these pathways 1, 2, 5.

Practical Clinical Algorithm

For a patient with mild adenomyosis undergoing embryo transfer:

1. Pre-treatment phase (2-3 months before transfer): Consider GnRH agonist suppression to improve endometrial receptivity 1, 2

2. Cycle planning: Utilize a long GnRH agonist protocol or plan for frozen embryo transfer after GnRH agonist pre-treatment 1, 2

3. At transfer: Perform standard embryo transfer technique with single embryo only 3, 4

4. Do not: Add uterine relaxants, as there is no evidence supporting this practice in adenomyosis patients

Common Pitfalls to Avoid

• Do not transfer multiple embryos based on the presence of adenomyosis or concerns about lower implantation rates—this dramatically increases multiple pregnancy risk without improving live birth rates 3, 4.

• Do not use acute interventions at transfer (such as uterine relaxants) when the evidence supports pre-treatment strategies that modify the disease process itself 1, 2.

• Do not assume that previous failed cycles in adenomyosis patients justify deviation from SET protocols 3.