Is the short luteal phase a defective luteal phase?

Novel approach using serum progesterone as a triage to guide management of patients with threatened miscarriage: a prospective cohort study

Threatened miscarriage is a common gynaecological emergency, with up to 25% of women eventually progressing to spontaneous miscarriage. The uncertainty of pregnancy outcomes results in significant anxiety. However, there is currently no acceptable framework for triaging patients presenting with threatened miscarriage. We aim to evaluate the efficacy and safety of a novel clinical protocol using a single serum progesterone level to prognosticate and guide management of patients with threatened miscarriage. 1087 women presenting with threatened miscarriage were enrolled in the study. The primary outcome was spontaneous miscarriage by 16 weeks’ gestation. Among the 77.9% (847/1087) of study participants with serum progesterone ≥ 35 nmol/L who were not treated with oral dydrogesterone, the miscarriage rate was 9.6% (81/847). This did not differ significantly from the 8.5% (31/364) miscarriage rate observed in our prior studies; p = 0.566. Among women with serum progesterone < 35 nmol/L who were treated with dydrogesterone, the miscarriage rate was 70.8% (170/240). Our novel clinical triage protocol using a single serum progesterone level allowed both effective risk stratification and a reduction in progestogen use with no significant adverse pregnancy outcomes. This protocol, based on a single serum progesterone cutoff, can be readily adapted for use in other healthcare institutions.

Dietary factors and luteal phase deficiency in healthy eumenorrheic women

STUDY QUESTION

Are prospectively assessed dietary factors, including overall diet quality, macronutrients and micronutrients, associated with luteal phase deficiency (LPD) in healthy reproductive aged women with regular menstrual cycles?

SUMMARY ANSWER

Mediterranean Diet Score (MDS), fiber and isoflavone intake were positively associated with LPD while selenium was negatively associated with LPD after adjusting for age, percentage body fat and total energy intake.

WHAT IS KNOWN ALREADY

LPD may increase the risk of infertility and early miscarriage. Prior research has shown positive associations between LPD and low energy availability, either through high dietary restraint alone or in conjunction with high energy expenditure via exercise, but few studies with adequate sample sizes have been conducted investigating dietary factors and LPD among healthy, eumenorrheic women.

STUDY DESIGN, SIZE, DURATION

The BioCycle Study (2005-2007) prospectively enrolled 259 women from Western New York state, USA, and followed them for one (n = 9) or two (n = 250) menstrual cycles.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Women aged 18-44 years, with self-reported BMI between 18 and 35 kg/m(2) and cycle lengths between 21 and 35 days, were included in the study. Participants completed baseline questionnaires, four 24-h dietary recalls per cycle and daily diaries capturing vigorous exercise, perceived stress and sleep; they also provided up to eight fasting serum samples during clinic visits timed to specific phases of the menstrual cycle using a fertility monitor. Cycles were included for this analysis if the peak serum luteal progesterone was >1 ng/ml and a urine or serum LH surge was detected. Associations between prospectively assessed diet quality, macronutrients and micronutrients and LPD (defined as luteal duration <10 days) were evaluated using generalized linear models adjusting for age, percentage body fat and total energy intake.

MAIN RESULTS AND THE ROLE OF CHANCE

LPD occurred in 41 (8.9%) of the 463 cycles from 246 women in the final analysis. After adjusting for age, percentage body fat and total energy intake, LPD was positively associated with MDS, adjusted odds ratio (aOR): 1.70 (95% confidence interval [CI]: 1.17, 2.48), P = 0.01. In separate macro- and micronutrient adjusted models, increased fiber and isoflavone intake showed modest positive associations with LPD: fiber (per g), aOR: 1.10 (95% CI: 0.99, 1.23), P = 0.07; and isoflavones (per 10 mg), aOR: 1.38 (95% CI: 0.99, 1.92), P = 0.06. In contrast, selenium (per 10 mcg) was inversely associated with LPD, aOR: 0.80 (95% CI: 0.65, 0.97), P = 0.03. Additional adjustments for relevant lifestyle factors including vigorous exercise, perceived stress and sleep did not appreciably alter estimates.

LIMITATIONS, REASONS FOR CAUTION

The number of LPD cycles was limited, and thus these findings are exploratory. We relied on participant self-report of their medical history to apply exclusion criteria; it is possible that we admitted to the study women with a gynecologic or medical disease who were unaware of their diagnosis.

WIDER IMPLICATIONS OF THE FINDINGS

Our study suggests that diet quality may be associated with LPD among healthy eumenorrheic women. As LPD may contribute to infertility and early miscarriage, further research is warranted to elucidate how dietary factors, such as MDS, may influence LPD. The inverse association we found with selenium is supported by previous research and deserves further investigation to determine whether this finding has pathophysiologic and therapeutic implications.

STUDY FUNDING/COMPETING INTERESTS

This work was supported by the Intramural Research Program, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health. No competing interests declared.

Luteal phase deficiency in regularly menstruating women: prevalence and overlap in identification based on clinical and biochemical diagnostic criteria

CONTEXT

Although adequate luteal hormone production is essential for establishing pregnancy, luteal phase deficiency (LPD) is poorly characterized among eumenorrheic women.

OBJECTIVE

We assessed the prevalence and overlap of two established LPD diagnostic criteria: short luteal phase duration less than10 days (clinical LPD) and suboptimal luteal progesterone of 5 ng/mL or less (biochemical LPD) and their relationship with reproductive hormone concentrations.

DESIGN, SETTING, AND PARTICIPANTS

We conducted a prospective study in western New York (2005-2007) following 259 women, aged 18-44 years, for up to two menstrual cycles.

RESULTS

Among ovulatory cycles with recorded cycle lengths (n = 463), there were 41 cycles (8.9%) with clinical LPD, 39 cycles (8.4%) with biochemical LPD, and 20 cycles (4.3%) meeting both criteria. Recurrent clinical and biochemical LPD was observed in eight (3.4%) and five (2.1%) women, respectively. Clinical and biochemical LPD were each associated with lower follicular estradiol (both P ≤ .001) and luteal estradiol (P = .03 and P = .02, respectively) after adjusting for age, race, and percentage body fat. Clinical, but not biochemical, LPD was associated with lower LH and FSH across all phases of the cycle (P ≤ .001).

CONCLUSIONS

Clinical and biochemical LPD were evident among regularly menstruating women. Estradiol was lower in LPD cycles under either criterion, but LH and FSH were lower only in association with shortened luteal phase (ie, clinical LPD), indicating that clinical and biochemical LPD may reflect different underlying mechanisms. Identifying ovulation in combination with a well-timed luteal progesterone measurement may serve as a cost-effective and specific tool for LPD assessment by clinicians and researchers.

Angiogenesis in the corpus luteum

The ovarian corpus luteum plays a critical role in reproduction because it is the primary source of circulating progesterone. After ovulation, as the corpus luteum forms from the wall of the ruptured follicle, it grows and vascularizes extremely rapidly. In fact, the rates of tissue growth and angiogenesis in the corpus luteum rival those of even the fastest growing tumors. Thus, the corpus luteum provides an outstanding model for studying the factors that regulate the angiogenic process, which is critical for normal tissue growth, development, and function. In agreement with data from other tissues, vascular endothelial growth factors (VEGF) seem to be a major angiogenic factor responsible for vascularization of the developing corpus luteum. Recent data suggest that luteal expression of VEGF occurs primarily in specific perivascular cells, including arteriolar smooth muscle and capillary pericytes, and is regulated primarily by oxygen levels. In addition, soon after ovulation, pericytes derived from the thecal compartment appear to be the first vascular cells to invade the developing luteal parenchyma. The granulosa-derived cells produce a factor that stimulates pericyte migration. Moreover, nitric oxide (NO), which is a potent vasodilator and can stimulate VEGF production and angiogenesis, is expressed in endothelial cells of luteal arterioles and capillaries, often in association with expression of VEGF by luteal perivascular cells. Thus, we have proposed a model for the initial process of luteal vascularization in which hypoxia plays a major role. In this model, which we believe will apply to other tissues as well, a paracrine loop exists between the vascular endothelial cells, which produce NO, and the peri-endothelial cells (vascular smooth muscle and pericytes), which produce VEGF, to ensure coordinate regulation of luteal vasodilation and angiogenesis.

The effect of cycle length on the outcome of in vitro fertilization

In order to study the effect of cycle length on the pregnancy rate in an in vitro fertilization and embryo transfer (IVF-ET) program, 173 consecutive patients were divided into short menstrual cycle (mode 26 days or less) and normal cycle (mode 27 days or more) groups. Patients were randomly allocated to one of two treatments, commencing ovarian stimulation with human menopausal gonadotropin (hMG) on either day 2 or day 4 of their cycle. The number of oocytes retrieved and embryos transferred did not differ significantly. The amount of hMG used and day of human chorionic gonadotrophin administration both differed significantly (P less than 0.01) between regimens but was independent of cycle length. Both the clinical pregnancy rate (30.2% versus 9.4%, P less than 0.05) and the number of cleaved embryos giving rise to gestation sacs (16% versus 3.4%, P less than 0.02) was significantly higher in patients with a normal cycle length. Mode cycle length has a significant bearing on the outcome of IVF-ET cycles.