Related Experiment Video
Updated: Aug 29, 2026

Laparoscopic Non-Mesh Cerclage Pectopexy for Pelvic Organ Prolapse
Published on: September 13, 2022
The Mirena levonorgestrel system
C Jay McGavigan1, Iain T Cameron
1Department of Obstetrics and Gynecology, Southern General Hospital, South Glasgow University Hospitals NHS Trust, Govan, Glasgow, UK.
Abstract:
The levonorgestrel intrauterine system is a safe, efficacious, long-term contraceptive device. Additionally, it results in a decrease in the volume of menstrual blood loss in women with normal periods and those with menorrhagia. It may also have a role in the treatment of other benign gynecological disorders, such as adenomyosis or endometriosis, and it has been advocated as a means of delivering progestogen to the endometrium as part of combined hormone replacement therapy. Despite the beneficial effect on menstrual volume, compliance is sometimes limited by breakthrough bleeding during the first months of use. The precise mechanism of this bleeding is unclear, but it may be related to a direct effect of levonorgestrel on endometrial vascular development. Detailed counseling is crucial to explain this anticipated side effect in order to reduce unnecessary discontinuation of treatment.
Related Concept Videos
Intrauterine Drug Delivery Systems
Birth Control Methods
Hormonal Regulation of the Menstrual Cycle
At puberty, GnRH begins a pulsatile release pattern, which triggers the anterior pituitary gland to secrete follicle-stimulating hormone (FSH) and luteinizing hormone (LH). The frequency and amplitude of GnRH pulses vary across the menstrual cycle, with faster pulses favoring LH release and slower pulses favoring FSH release.
Uterine Tubes
The Menstrual Cycle
The menstrual phase occurs from days 1 to 5 and involves the shedding of the stratum functionalis, as a uterine...
Hormonal Control of the Ovarian Cycle
Before puberty, the hypothalamus releases GnRH in a low frequency, low amplitude pulsatile manner. This along with the immature hypothalamic-pituitary-gonadal axis activity, results in low estrogen levels and the absence of a fully functional ovarian cycle. At puberty, GnRH secretion increases in both frequency and...
