Menstrual cycle length in reproductive age women is an indicator of oocyte quality and a candidate marker of ovarian reserve

Menstrual cycle characteristics and fecundability in a North American preconception cohort

“…These findings are consistent with those from the Danish preconception cohort (6) and the study of oocyte donors (9). However, other cohort studies reported that short (7) or long (7, 11) bleed lengths were associated with lower fecundability.…”

“…In 6,271 IVF treatment cycles in Sweden, cumulative pregnancy rates were lowest (16.9%) in women with cycles of <26 days and highest (31.3%) in women with cycles of 32–34 days (10). Likewise, in a Spanish IVF cohort, recipients whose donors had cycle lengths of 25–26 and 34–35 days had the lowest (RR=0.74) and highest (RR=1.37) risk of pregnancy, compared with donor cycles of 27–29 days (9, 21), indicating that the relation between cycle length and fertility may be due to oocyte quality rather than endometrial factors.…”

“…However, evidence assessing the association between long menstrual cycles and fecundability is inconsistent. In an IVF cohort, egg donors with regular menstrual cycles of 34–35 days had lower gonadotropin medication requirements, improved oocyte quality, and better cycle success compared with donors with menstrual cycles of 27–28 days (9). Cycle length has been positively associated with pregnancy rates in women undergoing IVF (10) and with improved fecundability among pregnancy planners (6), but also with increased risk of anovulation (2) and reduced fecundability (7, 8).…”

Antimüllerian hormone, antral follicle count and ovarian volume predict menstrual cycle length in healthy women

“…6 Oocyte donors with menstrual cycle lengths of 34-35 days have better oocyte quality and better response to ovarian stimulation compared to those with shorter cycles. 7 Lifestyle factors such as weight loss, caloric deficiency and exercise, cigarette smoking, alcohol/coffee consumption, shift work, sleep, stress and education/work patterns have been reported to affect menstrual cycle length. [10][11][12] In healthy women, the length of the menstrual cycle has been reported to vary with changes in pituitary hormones (FSH and LH) and oestradiol.…”

Ovarian Physiology and GWAS: Biobanks, Biology, and Beyond

“…Several biobanks have established female healthspecific questionnaires, thereby creating valuable datasets for reproductive health-related phenotypes which could also provide insight into ovarian biology. For example, a recent study proposed that menstrual cycle length could be a proxy marker for ovarian reserve and oocyte quality [13], and recently a GWAS for this trait was published, highlighting variants near the FSHB gene that encodes the b subunit of follicle-stimulating hormone (FSH) [14]. Because menstrual cycle length is among the phenotypes that some biobanks collect data for (relevant questions are included in the UK Biobank i , the Estonian Biobank ii , and the LifeLines Biobank iii female health questionnaires), we will probably soon have more information about the genetics of menstrual cycle.…”