About

Marla Lujan is an Associate Professor in the Division of Nutritional Sciences at Cornell University. She holds a Master of Science and a Doctor of Philosophy in Physiology from Queen's University in Kingston, Ontario. Her postdoctoral studies were conducted in Obstetrics, Gynecology, and Reproductive Sciences at the University of Saskatchewan. Her research focuses on the interplay of nutrition and metabolic status with women’s reproductive health, specifically investigating mechanisms by which diet, glucoregulatory status, and adiposity impact ovulation and lead to the loss of regular menstrual cycles, such as amenorrhea. Her group utilizes high-resolution ovarian ultrasonography to characterize follicle development during natural cycles, aiming to inform causes of anovulation like polycystic ovary syndrome (PCOS), and to assess the impact of diet and cardiometabolic factors on reproductive health. Her work also includes cross-disciplinary assessments of women with endocrine disruptions, examining dietary intake, physical activity, health-related knowledge, beliefs, and healthcare experiences.

Research topics

• Medicine
• Political Science
• Internal medicine
• Pathology
• Medical education
• Engineering
• Family medicine
• Zoology
• Endocrinology
• Anatomy
• Biology

Selected publications

• Geographical Variations in Polycystic Ovarian Morphology: Comparison of India- and United States-Based Women with Polycystic Ovary Syndrome

  Reproductive Medicine · 2026-02-21

  articleOpen accessSenior authorCorresponding

  Background/Objectives: Geographical differences exist in the clinical presentation of polycystic ovary syndrome (PCOS). The degree to which ovarian morphology contributes to this variability is unknown. Methods: This study compared ovarian ultrasound features between women with PCOS residing in two geographical regions (India and the United States) using stored de-identified ultrasound scans from 331 women with PCOS. Sonographic markers of interest included follicle number per ovary (FNPO), follicle number per cross-section (FNPS), ovarian volume (OV), ovarian area (OA), stromal area (SA), and stromal-to-ovarian area ratio (S/A). Results: Most participants in both regions met the accepted criteria for polycystic ovarian morphology (India 87% vs. U.S. 83%). The U.S.-based group had a higher prevalence of follicle excess (41% in U.S. vs. 29% in India; p = 0.037), whereas the prevalence of ovarian enlargement was similar across groups (India 37% vs. U.S. 31%, p = 0.252). FNPS was higher in the U.S.-based group (p = 0.046), while the India-based group had higher OV (p = 0.010). SA and S/A did not differ between groups, albeit OA was slightly larger in women with PCOS from India (p = 0.022). Associations between ovarian morphology and menstrual cycle length (ρ = 0.16–0.25), hirsutism score (ρ = 0.19–0.23), and total testosterone (ρ = −0.33–0.42) were noted in both groups (p < 0.05). Conclusions: Some variation in ovarian morphology may exist across geographic regions. However, the degree of variability is unlikely to warrant regional definitions for polycystic ovarian morphology at this time.

  PublisherOA PDFDOI

• Diagnosis of Polycystic Ovary Syndrome With Predictive Modeling of Select Clinical Features

  O&G Open · 2026-03-19

  articleOpen access

  OBJECTIVE: To determine whether a limited set of ultrasonographic, biochemical, and clinical features are sufficient to accurately predict polycystic ovary syndrome (PCOS) diagnosis. METHODS: Transvaginal ultrasound images and available clinical data for participants with PCOS (n=101) and controls (n=50) were used for this multicenter, retrospective pilot study. Diagnosis of PCOS was defined by the 2023 International Evidence-Based Guideline. Controls had no diagnostic features of PCOS. Differences in demographic (age, body mass index [BMI]), ultrasonographic (ovarian volume, follicle number per ovary, follicle number per single cross section), biochemical (sex hormone binding globulin, total testosterone, free androgen index, bioavailable testosterone), and clinical (follicle-stimulating hormone, luteinizing hormone, estradiol, anti-müllerian hormone (AMH), age at menarche, minimum self-reported menstrual cycle length in the past year, maximum self-reported menstrual cycle length in the past year, Ferriman–Gallwey hirsutism score) features between groups were assessed with Mann–Whitney U tests. A logistic regression model was trained to predict PCOS diagnosis using subsets of ultrasonographic, biochemical, and clinical variables. Model performance was evaluated with area under the receiver operating characteristic curve (AUROC) and F1 score measures. RESULTS: Anti-müllerian hormone alone predicted PCOS diagnosis with relatively good diagnostic accuracy (AUROC 0.884, F1 score 0.807). Integration of AMH and ovarian volume improved model performance (AUROC 0.906, F1 score 0.811). Integration of all ultrasonographic, biochemical, and clinical features yielded a high-performing model with excellent diagnostic accuracy for PCOS (AUROC 0.991, F1 score 0.811). Refinement of the model to a limited set of readily obtained variables, including AMH, ovarian volume, hirsutism score, and maximum self-reported menstrual cycle length, yielded a model with strong performance (AUROC 0.982, F1 score 0.805). CONCLUSION: A minimum combination of ovarian volume with AMH and examination/history–derived end points can accurately predict PCOS diagnosis with performance comparable to that of a combination of all ultrasonographic, biochemical, and clinical features. This may streamline diagnostic workflows, thereby reducing clinical burden. PARENT PROTOCOL CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov, NCT01859663, NCT01927471, NCT03306849, NCT01927432, NCT03547453.

  PublisherDOI

• Impact of Polycystic Ovary Syndrome Status on Changes in Reproductive Function During a Hypocaloric Dietary Intervention

  Nutrients · 2026-02-16

  articleOpen accessSenior author

  Background/Objectives: Lifestyle interventions are first-line treatment for women with polycystic ovary syndrome (PCOS) to improve metabolic health. Impacts on reproductive function are less clear. Previous research has been limited by inconsistencies in evaluation of ovulatory function and lack of comparisons between women with and without PCOS. Methods: The present study implemented a prospective clinical trial of 28 women (PCOS, N = 10 and Non-PCOS Control, N = 18) undergoing a 1-month baseline assessment followed by a 6-month hypocaloric dietary intervention. Results: Both groups reached clinically meaningful weight loss with the intervention (PCOS group: 6.5 ± 5.5%; Non-PCOS Control group: 10.0 ± 4.7%). Largest follicle diameter and growth rate of ovulatory dominant follicle, menstrual cycle length and luteal phase length did not change during the intervention in either group (all p > 0.05). The Non-PCOS Control group had increased mid-luteal phase progesterone levels and secretory phase maximum endometrial thickness during the intervention (all p < 0.05), whereas the PCOS group showed a reduction in follicular phase length (p < 0.05). Additionally, changes in ovulatory function and endometrial development were not associated with the rate of weight loss (all p > 0.05). Conclusions: This study demonstrates that women with PCOS are unlikely to experience changes in menstrual cyclicity and endometrial development with a short-term hypocaloric dietary intervention. The shortening of the follicular phase suggests that women with PCOS may need a longer intervention to achieve clinically meaningful improvements in ovulatory function and endometrial health.

  PublisherDOI

• Disrupted Sleep Behaviors are associated with PCOS Risk in Post-Menarcheal Adolescents

  Physiology · 2025-05-01

  article

  Introduction: Polycystic Ovary Syndrome (PCOS) is a common endocrine disorder that often develops during adolescence. Disrupted sleep and altered circadian rhythm contribute to obesity and insulin resistance—both risk factors for PCOS—and may play a role in its pathophysiology. While cross-sectional studies suggest a connection, they provide limited insight into the relationship between sleep behavior and PCOS onset. The objective of this ancillary study was to determine whether morning or evening preference, and indicator of circadian rhythm, and sleep disturbances, sleep hygiene, and sleep quality within the first-year post-menarche are associated with PCOS, diagnostic features of PCOS, or metabolic abnormalities associated with PCOS. We hypothesized that poor sleep behaviors and eveningness preference in early post-menarche will correlate with future PCOS onset. Methods: A secondary analysis of a prospective cohort study in post-menarcheal adolescents (n=31). Study visits were timed with gynecological age: 6-10 months, 11-13-, 17-19-, and 23-25 months post-menarche. At each study visit, participants completed two sleep questionnaires: the Morningness/Eveningness and Children's Reports of Sleep Patterns questionnaires. Responses during the first year (6-10 months and 11-13 months) were evaluated individually and averaged, to assess sleep disruptions during the first post-menarcheal year. Whether sleep variables within the first gynecological year were associated with either PCOS onset at the end of study participation or individual PCOS symptoms were evaluated using Mann-Whitney U-Tests and Spearman’s rank correlation coefficients. Results: Adolescents who met criteria for PCOS at the end of study participation (n=7) had higher Morningness-Eveningness Scale (MES) scores, indicating a stronger morning preference, during the first year post-menarche (6–10 months after menarche) versus those who developed regular menstrual cycles with no androgen excess (n=10) (32 [31–33] vs. 26 [22–28], p = 0.04). A stronger morning preference also correlated with a higher free androgen index (rho = 0.689, p=0.001), which is a diagnostic feature of PCOS. Greater sleepiness scores during first year post-menarche were associated with lower Sex Hormone Binding Globulin (rho = -0.505, p =0.009), while sleepiness at one-year post-menarche showed a trend toward higher fasting insulin levels at the study's end (rho = 0.411, p=0.064). Lower sleep disturbance scores averaged over the first year were associated with higher total testosterone (rho = -0.483, p =0.013), and a stronger morning preference over the same period showed a trend toward higher total testosterone (rho = 0.368, p = 0.084). warranting further research into whether morningness preference reflects inherent circadian differences in adolescents predisposed to PCOS. Conclusion: Circadian preferences and sleep patterns may influence PCOS development in the early post-menarcheal years, however studies are needed with larger samples to support this finding. Additional research is underway to evaluate overnight melatonin production as a physiological biomarker of sleep disturbances. Funding support: National Institutes of Health (PI: M Lujan), Canadian Institutes of Health Research (PI: H Vanden Brink), and Texas A&M AgriLife (PI: H Vanden Brink). This abstract was presented at the American Physiology Summit 2025 and is only available in HTML format. There is no downloadable file or PDF version. The Physiology editorial board was not involved in the peer review process.

  PublisherDOI

• Psychological symptoms in perimenarcheal adolescents: association with PCOS risk factors

  Frontiers in Endocrinology · 2025-06-12 · 1 citations

  articleOpen access

  Introduction: PCOS is linked with disproportionately high rates of depression and anxiety that significantly compromise quality of life and pose problems for treatment eligibility and adherence. The overarching objective of the proposed manuscript is to define the presence and severity of psychological symptoms in peri-menarcheal adolescents, and their association with well-described risk-factors for future PCOS. Methods: Fifty-two pre- and early post-menarcheal participants underwent a non-fasting blood draw to measure reproductive hormones (Anti-Mullerian Hormone (AMH), Luteinizing Hormone (LH), Follicle Stimulating Hormone (FSH), Total Testosterone, Sex Hormone Binding Globulin (SHBG) and HbA1c, anthropometry, menstrual history (if post-menarcheal), and a series of surveys to evaluate depression (CES-DC), anxiety (MASC) and, as a novel approach, rumination, which is a transdiagnostic psychological process and early prodromal risk for psychological disorders. Parents/legal guardians completed a demographics survey. Random Forest analysis was used to predict depression, anxiety, and rumination from a predetermined set of variables in this participant sample. Results: for depression, anxiety, and rumination from the random forest model were 0.557, 0.555, and 0.597, respectively, suggesting overall good explanatory power for psychological outcomes. Parent education (Portion Sum of Squares (SS) = 11.4%) followed by AMH (Portion SS = 10.9%) and waist-hip-ratio (WHR) (Portion SS = 9.2%) were the most important variables in predicting depression. LH: FSH ratio was the most important variable in the dataset used to differentiate participants along the observed anxiety score continuum (Portion SS = 0.112 (11%) followed by HbA1c (Portion SS = 8.1%) and WHR (Portion SS = 7.9%). SHBG was the most frequently identified variable to differentiate participants reporting rumination (Portion SS = 13.3%) followed by Free Androgen Index (Portion SS = 6.9%) and WHR (Portion SS = 6.9%). Adolescents at high risk for progression to PCOS may already experience psychological vulnerabilities prior to a clinical diagnosis or full manifestation of PCOS. Our study findings highlight PCOS as a lifelong, multifaceted health condition with ramifications earlier than commonly documented.

  PublisherOA PDFDOI

• DEVELOPMENT OF AN ARTIFICIAL INTELLIGENCE FOUNDATION MODEL FOR THE INTERPRETATION OF PELVIC ULTRASONOGRAPHY

  Fertility and Sterility · 2025-12-01

  article
  PublisherDOI

• Utility of Polycystic Ovarian Morphology on Ultrasonography Across Menstrual Cycle Phases to Aid in the Diagnosis of Polycystic Ovary Syndrome ( <scp>PCOS</scp> )

  Journal of Ultrasound in Medicine · 2025-08-27 · 1 citations

  articleSenior authorCorresponding

  Objectives Determine the diagnostic accuracy of ovarian morphology on ultrasonography for polycystic ovary syndrome (PCOS) across the menstrual cycle. Methods Data from 25 women with PCOS (oligo‐anovulation + androgen excess) and 40 age‐ and BMI‐matched controls (regular cycles + normal androgens) with consecutive ultrasound scans over ≥2 menstrual cycle phases were included in this retrospective analysis. Phases of interest included: early follicular (1–6 days following menses onset), late follicular (1–7 days prior to ovulation in the presence of a dominant follicle), early luteal (1–7 days following ovulation), and late luteal (1–7 days prior to the onset of menses). Diagnostic accuracy (area under the ROC curve [AUC], sensitivity [Se], specificity [Sp]) of mean, maximum, and contralateral (ovary without dominant follicle or corpus luteum) sonographic measures for follicle number per ovary (FNPO), follicle number per single section (FNPS), and ovarian volume (OV) at each phase were determined. DeLong tests determined differences in diagnostic accuracy across phases. Results FNPO, FNPS, and OV all had significant diagnostic accuracy for PCOS across menstrual cycle phases. OV mean had the highest diagnostic accuracy for PCOS in the early follicular phase (AUC = 0.87, Se = 65%, Sp = 95%), whereas OV contralateral had the highest accuracy in both the early (AUC = 0.81, Se = 62%, Sp = 92%) and late luteal phases (AUC = 0.93, Se = 100%, Sp = 70%). OV contralateral outperformed all other measures in the late luteal phase ( P &lt; .05). Conclusion Ultrasonographic evaluations for PCOS may be performed across the menstrual cycle. The presence of a dominant follicle in the late follicular phase did not impact the performance of ovarian markers for PCOS status. By contrast, polycystic ovarian morphology is best defined in the luteal phase by assessments of FNPO and OV in the contralateral ovary.

  PublisherDOI

• Impact of Hypocaloric Dietary Intervention on Phenotypic Presentations of Polycystic Ovary Syndrome (PCOS)

  Nutrients · 2025-07-04 · 2 citations

  articleOpen accessSenior authorCorresponding

  Background/Objective: Lifestyle intervention is recommended as first-line treatment for polycystic ovary syndrome (PCOS). This pilot study aimed to determine if a short-term hypocaloric dietary intervention induced changes in the phenotypic presentation of PCOS. Methods: Twenty women with PCOS and overweight/obesity participated in a 3-month hypocaloric dietary intervention with a 6-month follow-up. At pre-intervention, post-intervention, and follow-up, assessments of menstrual cycle status, hyperandrogenism, and polycystic ovarian morphology were performed, and PCOS phenotype status was determined using the following scale of decreasing severity: Phenotype A (ovulatory dysfunction, hyperandrogenism, and polycystic ovaries), Phenotype B (ovulatory dysfunction and hyperandrogenism), Phenotype C (hyperandrogenism and polycystic ovaries), or Phenotype D (ovulatory dysfunction and polycystic ovaries). Results: The participants lost 8 ± 3% of their initial body weight with the intervention (p &lt; 0.001). Eight (40%) participants experienced a favorable shift in PCOS phenotype, while the remaining 12 (60%) participants had an unfavorable shift or no change. Changes in PCOS phenotype were primarily driven by reductions in menstrual cycle length (p = 0.010) and follicle number per ovary (p = 0.017), albeit no baseline clinical variable predicted a favorable-change PCOS presentation. At the 6-month follow-up (N = 12), weight was increased (p &lt; 0.05), and seven participants (58%) had reverted to a more severe phenotype. Conclusions: Weight loss may provide temporary improvement in the phenotypic presentation of PCOS, yet sustained lifestyle change may be required to maintain these benefits.

  PublisherOA PDFDOI

• Changes in antral follicle dynamics following weight loss in women with polycystic ovary syndrome

  Human Reproduction · 2025-08-13 · 4 citations

  articleSenior author

  STUDY QUESTION: Does weight loss from a hypocaloric dietary intervention improve antral follicle dynamics in women with PCOS? SUMMARY ANSWER: During a 3-month hypocaloric dietary intervention, women with PCOS who experienced clinically meaningful weight loss showed more organized antral follicle development including fewer recruitment events, but no change in the overall frequency of selection, dominance, or ovulation. WHAT IS KNOWN ALREADY: There is a spectrum of disordered antral follicle development in women with PCOS including excessive follicle recruitment and turnover, decreased frequency of selection and dominance, and failure of ovulation. Lifestyle intervention aimed at weight loss is recommended to improve metabolic health in women with PCOS yet benefits on ovarian follicle development and ovulation are unclear. STUDY DESIGN, SIZE, DURATION: This was a prospective, single-arm lifestyle intervention study conducted over 4 months including a 1-month baseline assessment period and 3-month hypocaloric dietary intervention. Twenty women were allocated to the intervention with 0% attrition. PARTICIPANTS/MATERIALS, SETTING, METHODS: Females, ages 18-38 years, with PCOS and obesity (BMI > 30 kg/m2) underwent every-other-day transvaginal ultrasonography and venipuncture at an academic clinical research unit for 4 months. The number and size of all follicles were evaluated at each study visit, with individual growth profiles plotted retrospectively for follicles that grew to at least 7 mm. Gonadotropin and ovarian steroid hormone concentrations were measured every-other-day. Reproductive, anthropometric, and metabolic status markers were assessed at baseline and at the end of the intervention. MAIN RESULTS AND THE ROLE OF CHANCE: Hypocaloric dietary intervention resulted in an average weight loss of 8 ± 3% with significant reductions in all anthropometric markers assessed including BMI, waist circumference, total percent fat, and trunk fat mass (all P < 0.05). Of the glucoregulatory and cardiovascular risk markers assessed, only diastolic blood pressure (P = 0.040) and 2-h insulin concentrations following a glucose challenge (P = 0.029) were decreased post-intervention. Antral follicle development appeared more cyclic following the intervention with the frequency of recruitment (P = 0.043), and number of follicles recruited per cohort (P < 0.0001), decreasing with weight loss. By contrast, the frequency of selection, dominance, and ovulation did not change with weight loss (all P < 0.05). When ovulation occurred during the intervention, the size at selection for ovulatory follicles decreased with weight loss (P < 0.0001), whereas maximum luteal progesterone levels increased with weight loss (P = 0.036). Participants (35%) who responded to the intervention with a shortened inter-menstrual interval had lower baseline trunk fat mass (P = 0.048), fasting insulin (P = 0.022), and homeostatic model assessment for insulin resistance (P = 0.017) compared to non-responders. LIMITATIONS, REASONS FOR CAUTION: The duration of the intervention may not have been sufficient to capture an impact of weight loss on ovulatory cyclicity. Analyses were limited to the antral stages of follicle development and any impact of hypocaloric dietary intervention on pre-antral folliculogenesis was not evaluated. The small study sample limits statistical power and generalizability of the findings. WIDER IMPLICATIONS OF THE FINDINGS: Short-term hypocaloric dietary intervention did not consistently improve ovulation frequency in women with PCOS despite clinically meaningful weight loss. Counseling related to the benefits of short-term hypocaloric dietary intervention on reproductive health outcomes should be tempered as improvements in ovulation are likely only in those with a more favorable metabolic profile at the onset. Improvements in the early stages of antral follicle development with weight loss suggest potential for longer dietary interventions to improve ovulatory cyclicity in women with PCOS. STUDY FUNDING/COMPETING INTEREST(S): This research was supported by funds from the President's Council of Cornell Women, United States Department of Agriculture (Grant No. 8106), and National Institutes of Health (R01-HD0937848, R56-HD089962). F.E.C., B.Y.J., and H.V.B. were supported by doctoral training awards from the National Institutes of Health (5 T32-HD087137, T32-DK007158) and Canadian Institutes of Health Research (Grant No. 146182), respectively. The authors have no competing interests. TRIAL REGISTRATION NUMBER: NCT01785719.

  PublisherDOI

• 151 Presence and Severity of Acne in Pre- and Post-Menarcheal Adolescents: A Pilot Study

  Journal of Investigative Dermatology · 2025-11-01

  article
  PublisherDOI

Recent grants

• Relevance of polycystic ovarian morphology in the clinical evaluation of PCOS

  NIH · $2.4M · 2018–2025

• Ovarian ultrasonography for the clinical evaluation of polycystic ovary syndrome.

  NIH · $300k · 2017–2019

Frequent coauthors

• Heidi Vanden Brink

  Texas A&M University

  35 shared

• Jacqueline Boyle

  34 shared

• Lisa Moran

  Monash University

  30 shared

• Brittany Y Jarrett

  Cornell University

  30 shared

• Carolyn Ee

  Flinders University

  29 shared

• Robert J. Norman

  University of Adelaide

  29 shared

• Helena Teede

  27 shared

• Kathleen M. Hoeger

  University of Rochester Medical Center

  26 shared

Labs

• Marla Lujan LabPI

Education

• Ph.D., Physiology

  Queen's University

• M.S., Physiology

  Queen's University

• Other, Obstetrics, Gynecology and Reproductive Sciences

  University of Saskatchewan

Awards & honors

• Fellow, SUNY Hispanic Leadership Institute (HLI)