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Reproductive Endocrinology · Ovulation Physiology

Incidence of the luteinized unruptured follicle phenomenon in cycling women

Kerin JF, Kirby C, Morris D, McEvoy M, Ward B, Cox LW

Published November 1983 Fertility and Sterility, 40(5), 620-626
DOI 10.1016/s0015-0282(16)47420-0 PMID 6628705

RRM Academy Synopsis

Luteinized unruptured follicle appeared in 4.9% of 183 cycles

The luteinized unruptured follicle (LUF) appeared in 9 of 183 cycles, or 4.9%, in a 1983 Australian cohort of 66 women with regular cycles. Daily ultrasound tracked them. The LUF recurred in only one woman, in a fourth follow-up cycle. The women had blocked tubes or partners with severe sperm problems.

Key Findings

  • Daily ultrasound found a luteinized unruptured follicle in 9 of 183 monitored cycles, an incidence of 4.9%, among 66 women with regular cycles.
  • The LUF occurred in 4 of 85 cycles (4.7%) in 31 women with bilateral tubal occlusion, and in 5 of 98 cycles (5.1%) in 35 women with severe male factor partners.
  • Eight women with an LUF were followed through further cycles. The LUF recurred once, in the fourth of six consecutive follow-up cycles in one woman.
  • In the nine women with an LUF, the luteinizing hormone surge, progesterone, and phase lengths stayed in normal ranges. Estradiol trended low-normal in the luteal phase without a significant difference.
  • Five women treated for endometriosis, monitored over 12 cycles, showed no LUF. Six women with unexplained infertility, monitored over 15 cycles, showed one LUF and one cycle without ovulation.

Interpretation

This cohort study followed 66 women with regular cycles. Some had blocked tubes. Some had partners with severe sperm problems. Daily ultrasound tracked 183 cycles. The luteinized unruptured follicle, or LUF, showed up in 4.9% of cycles. Among eight women followed longer, it came back just once. Hormone levels in LUF cycles, including the luteinizing hormone surge and progesterone, stayed in the normal range. The authors note they found the LUF using ultrasound criteria alone. The findings support larger studies of the LUF in women evaluated for infertility.

RRM Context

Fertility awareness charts mark ovulation by a temperature shift and a rise in progesterone. Ultrasound shows whether the follicle actually broke open. In this study, hormone levels in LUF cycles stayed normal. A chart alone would read these cycles as ovulatory. Unexplained infertility is undiagnosed. Pairing cycle charts with ultrasound can catch a follicle that hormones miss.

Our editorial summary of this paper, not the article's abstract.

Abstract

A prospective study is presented in order to determine the frequency of the luteinized unruptured follicle (LUF) in a population of 66 regularly cycling women. They were monitored by daily ultrasound for a total of 183 cycles, and the LUF was detected in 9 cycles, giving an incidence of 4.9%. The results of daily changes of luteinizing hormone, estradiol, and progesterone provide support for the thesis that the LUF behaves steroidogenically as a corpus luteum and that the luteal phase duration is normal. Continued monitoring in 35 cycles revealed a recurrence in only one case during a fourth subsequent cycle. Thus, the findings indicate that the LUF is a sporadic and infrequent phenomenon. It is therefore an uncommon cause of infertile cycles in potentially fertile women and represents a biologic variable rather than a syndrome. Based on ultrasonic and endocrine observations, a mechanism is proposed for the resolution of the LUF.

Topics

By this author

Related research

Reproductive Endocrinology › Ovulation Physiology › Luteinized Unruptured Follicle Syndrome · Menstrual Cycle › Cycle Disorders › Ovulatory Disturbances · Diagnostics › Ultrasound › Follicular Monitoring
John F. Kerin, Christine Kirby, David Morris, Michael McEvoy, Bruce Ward, Lloyd W. Cox
Jack Kerin, J Kerin, Chris Kirby, C Kirby, Dave Morris, D Morris, Mike McEvoy, M McEvoy, B Ward, L Cox
PMID 6628705 6628705 DOI 10.1016/s0015-0282(16)47420-0 10.1016/s0015-0282(16)47420-0 Kerin et al. 1983, Kerin 1983

Keywords

Adult, Corpus Luteum/physiology, Female, Humans, Infertility, Female/etiology, Luteinizing Hormone/blood, Menstruation, Ovarian Follicle/anatomy & Histology/physiology, Ovulation, Prospective Studies, Time Factors, Ultrasonography, Luteinizing Hormone

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