Abstract
Research question
What is the optimal lead follicle size in letrozole, human menopausal gonadotrophin
and intrauterine insemination (IUI) cycles with and without spontaneous LH surges?
Design
This retrospective cohort study included 3797 letrozole HMG IUI cycles between January
2010 and May 2021. All cycles were divided into two groups: the HCG trigger group
(trigger day LH ≤15 mIU/ml) and the spontaneous LH surge group (trigger day LH >15
mIU/ml). These two groups were subdivided into smaller groups based on the diameter
of the follicles. The primary outcome measure was clinical pregnancy rate. Logistic
regression analysis was conducted to explore other risk factors.
Results
In the HCG trigger group, the clinical pregnancy rate varied significantly, with rates
of 20.8%, 14.9% and 11.8% for the 16.1–18.0, 18.1–20.0 and 20.1–22.0 mm groups, respectively
(P = 0.005). In the spontaneous LH surge group, the pregnancy rate of follicles within
14.1–16.0 mm was significantly higher than that of follicles within 20.1–22.0 mm (adjusted
OR 0.533, 95% CI 0.308 to 0.923, P = 0.025). Also, patients with two lead follicles were 2.569 times more likely to
achieve a clinical pregnancy than those with only one lead follicle (adjusted OR 2.569,
95% CI 1.258 to 5.246, P = 0.010). The duration of infertility was also found to be a common influencing factor
in both groups.
Conclusions
The optimal lead follicle size was between 16.1 and 18.0 mm in HCG-triggered letrozole
HMG IUI cycles. If the lead follicle size is relatively small (14.1–18.0 mm) when
a spontaneous LH surge occurs, there is no need to cancel the IUI cycle.
KEYWORDS
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Biography
Kuang Yanping MD, PhD, is Director of the Department of Assisted Reproductive Medicine at Shanghai Ninth People's Hospital. He is Chairman of the Professional Committee on Reproductive Health, China Association of Rehabilitation Medicine, and Vice Chairman of the Reproductive Medicine branch, China International Exchange and Promotive Association for Medical and Health Care.
Article info
Publication history
Published online: November 06, 2022
Accepted:
November 3,
2022
Received in revised form:
September 28,
2022
Received:
August 1,
2022
Declaration: The authors report no financial or commercial conflicts of interest.Identification
Copyright
© 2022 Reproductive Healthcare Ltd. Published by Elsevier Ltd. All rights reserved.
