Synchronised approach for intrauterine insemination in subfertile couples

Area of Science:

• Reproductive Medicine
• Infertility Treatment
• Evidence-Based Medicine

Background:

• Intrauterine insemination (IUI) is a common first-line treatment for subfertility.
• Pregnancy rates with IUI vary significantly, and optimal timing strategies remain unclear.
• This review updates a previous Cochrane review from 2014.

Purpose of the Study:

• To evaluate the effectiveness of different methods for synchronizing insemination with ovulation.
• To assess outcomes such as live birth and clinical pregnancy rates in natural and stimulated IUI cycles.
• To identify optimal timing approaches and ovulation monitoring/triggering techniques for IUI.

Main Methods:

• Systematic review and meta-analysis of randomized controlled trials (RCTs).
• Searched multiple databases up to October 2023, including Cochrane Gynaecology and Fertility Group register, CENTRAL, and MEDLINE.
• Included 42 studies (6603 couples) comparing various timing methods, ovulation detection (LH, ultrasound, BBT), and trigger agents (hCG, GnRH agonists).

Main Results:

• The certainty of evidence for most comparisons was low, primarily due to imprecision.
• No clear differences in live birth or ongoing pregnancy rates were found when comparing different time intervals from hCG injection to IUI (0-33 hours vs. 34-40 hours vs. >40 hours).
• Live birth rates may be lower with hCG alone compared to hCG plus FSH, but evidence is low-certainty.

Conclusions:

• There is insufficient evidence to recommend specific methods for synchronizing insemination with ovulation in IUI.
• The effectiveness of different timing strategies and ovulation triggering methods requires further investigation.
• More high-quality RCTs are needed to provide definitive guidance on optimizing IUI timing for improved pregnancy outcomes.