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Subject: LH surge

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    Review
    Citation - Scopus: 43
    The Lh Surge and Ovulation Re-Visited: a Systematic Review and Meta-Analysis and Implications for True Natural Cycle Frozen Thawed Embryo Transfer
    (Oxford University Press, 2022) Erden,M.; Mumusoglu,S.; Polat,M.; Yarali Ozbek,I.; Esteves,S.C.; Humaidan,P.; Yarali,H.
    BACKGROUND: Efficient and safe embryo vitrification techniques have contributed to a marked worldwide increase in the use of elective frozen embryo transfer (FET). Pinpointing the day of ovulation, more commonly by documentation of the LH surge and less commonly by ultrasonography, is crucial for timing of FET in a true natural cycle (t-NC) to maximize the reproductive outcome. OBJECTIVE AND RATIONALE: The definition of the onset of the LH surge should be standardized in t-NC FET cycles; however, a clear definition is lacking in the available literature. The first search question concerns the definition of the onset of the LH surge in a natural cycle. The second search question relates to the duration between the onset of the LH surge and ovulation. SEARCH METHODS: We searched PubMed, Web of Science and Cochrane Library databases for two search questions from inception until 31 August 2021. 'Luteinizing hormone'[MeSH] OR 'LH' AND 'surge' terms were used to identify eligible articles to answer the first question, whereas 'Luteinizing hormone'[MeSH] OR 'LH' AND 'surge' OR 'rise' AND 'ovulation'[MeSH] OR 'follicular rupture' OR 'follicular collapse' were the terms used regarding the second question. The included publications were all written in the English language, conducted in women of reproductive age with regular ovulatory cycles and in whom serial serum or urine LH measurement was performed. For the quality and risk of bias assessment of the included studies, the Strengthening the Reporting of Observational Studies in Epidemiology and modified Newcastle Ottawa Scale were used. OUTCOMES: A total of 10 and 8 studies were included for search Questions 1 and 2, respectively. Over the years, through different studies and set-ups, testing in either serum or urine, different definitions for the onset of the LH surge have been developed without a consensus. An increase in LH level varying from 1.8- to 6-fold above the baseline LH level was used in seven studies and an increase of at least two or three standard deviations above the mean of the preceding LH measurements was used in two studies. An LH level exceeding the 30% of the amplitude (peak-baseline LH level) of the LH surge was defined as the onset day by one study. A marked inter-personal variation in the time interval between the onset of the LH surge and ovulation was seen, ranging from 22 to 56 h. When meta-analysis was performed, the mean duration in hours between the onset of the LH surge and ovulation was 33.91 (95% CI = 30.79-37.03: six studies, 187 cycles). WIDER IMPLICATIONS: The definition of the onset of the LH surge should be precisely defined in future well-designed studies employing state-of-art laboratory and ultrasonographic equipment. The window of implantation in a natural cycle is still a black box, and future research is warranted to delineate the optimal interval to time the embryo transfer in t-NC FET cycles. Randomized controlled trials employing different precise endocrine and/or ultrasonographic criteria for timing of FET in a t-NC are urgently required. © 2022 The Author(s). Published by Oxford University Press on behalf of European Society of Human Reproduction and Embryology. All rights reserved.
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    Article
    Citation - WoS: 7
    Citation - Scopus: 7
    Vitrified-Warmed Blastocyst Transfer Timing Related To Lh Surge in True Natural Cycle and Its Impact on Ongoing Pregnancy Rates
    (Elsevier Sci Ltd, 2022) Erden, Murat; Polat, Mehtap; Mumusoglu, Sezcan; Ozbek, Irem Yarali; Dere, Gonca Ozten; Sokmensuer, Lale Karakoc; Yarali, Hakan
    Research question: Does the timing of warmed blastocyst transfer in true natural cycle (tNC) differ according to six different commonly used definitions of LH surge, and do differences in timing have any impact on ongoing pregnancy rate (OPR)?Design: Prospective monitoring, including repeated blood sampling and ultrasound analyses of 115 warmed blastocyst transfer cycles performed using tNC between January 2017 and October 2021.Results: The reference timing of follicular collapse +5 days would be equivalent to LH surge +6 days in only 5.2- 41.2% of the cycles employing the six different definitions of the LH surge. In contrast, the reference timing was equivalent to LH surge +7 days in the majority of cycles (46.1-69.5%) and less commonly to LH surge +8 days (1.8- 38.3%) and +9 days (0-10.4%). For each definition of the LH surge, the OPR were comparable among the different warmed blastocyst transfer timings related to the LH surge (LH surge +6/+7/+8/+9 days). When logistic regression analysis was performed to evaluate the independent effect of variation of warmed blastocyst transfer timing (LH surge +6/+7/+8/+9 days) on OPR and taking LH surge +6 days as the reference, change in timing was not an independent predictor of OPR for any of the definitions of the LH surge.Conclusions: Employing a policy of performing warmed blastocyst transfer on follicular collapse +5 days and using six different definitions of the LH surge, vitrified-warmed embryo transfer timing is indeed equivalent to LH surge +7/+8 and even +9 days in a significant proportion of tNC with comparable reproductive outcomes.