Reproductive factors and mammographic density within the International Consortium of Mammographic Density: A cross-sectional study.

BACKGROUND: Elevated mammographic density (MD) for a woman's age and body mass index (BMI) is an established breast cancer risk factor. The relationship of parity, age at first birth, and breastfeeding with MD is less clear. We examined the associations of these factors with MD within the International Consortium of Mammographic Density (ICMD). METHODS: ICMD is a consortium of 27 studies with pooled individual-level epidemiological and MD data from 11,755 women without breast cancer aged 35-85 years from 22 countries, capturing 40 country-& ethnicity-specific population groups. MD was measured using the area-based tool Cumulus. Meta-analyses across population groups and pooled analyses were used to examine linear regression associations of square-root (√) transformed MD measures (percent MD (PMD), dense area (DA), and non-dense area (NDA)) with parity, age at first birth, ever/never breastfed and lifetime breastfeeding duration. Models were adjusted for age at mammogram, age at menarche, BMI, menopausal status, use of hormone replacement therapy, calibration method, mammogram view and reader, and parity and age at first birth when not the association of interest. RESULTS: Among 10,988 women included in these analyses, 90.1% (n = 9,895) were parous, of whom 13% (n = 1,286) had ≥ five births. The mean age at first birth was 24.3 years (Standard deviation = 5.1). Increasing parity (per birth) was inversely associated with √PMD (ß: - 0.05, 95% confidence interval (CI): - 0.07, - 0.03) and √DA (ß: - 0.08, 95% CI: - 0.12, - 0.05) with this trend evident until at least nine births. Women who were older at first birth (per five-year increase) had higher √PMD (ß:0.06, 95% CI:0.03, 0.10) and √DA (ß:0.06, 95% CI:0.02, 0.10), and lower √NDA (ß: - 0.06, 95% CI: - 0.11, - 0.01). In stratified analyses, this association was only evident in women who were post-menopausal at MD assessment. Among parous women, no associations were found between ever/never breastfed or lifetime breastfeeding duration (per six-month increase) and √MD. CONCLUSIONS: Associations with higher parity and older age at first birth with √MD were consistent with the direction of their respective associations with breast cancer risk. Further research is needed to understand reproductive factor-related differences in the composition of breast tissue and their associations with breast cancer risk.

Differences in Abdominal and Lumbar Muscle Thickness and Contractile Function Between Nulliparous, Primiparous, and Multiparous Women 6 Months Postpartum.

OBJECTIVE: The purpose of this study was to evaluate the differences between primiparous and multiparous women at 6 months postpartum and nulliparous women regarding the thickness (including thickness pattern) and contractile function of the abdominal and lumbar muscles. METHODS: A cross-sectional observational study of 80 women, both primiparous (n = 29) and multiparous (n = 25), as well as including nulliparous as a comparison group (n = 26), was conducted. B-mode ultrasound imaging was used for the measurement of abdominal and lumbar muscle thickness in 2 conditions (resting and activation). Moreover, the contractile function of these muscles was determined by the thickness ratio. RESULTS: Significant differences between groups were observed in abdominal muscle thickness. During activation, the obliques showed a lower thickness in both groups of postpartum women compared to nulliparous women, while lower values for the thickness for the transverse abdominis (TrA) were only observed in primiparous women. The thickness pattern observed in nulliparous women both in resting and in activation (internal oblique [IO] > external oblique [EO] > TrA) was also achieved among postpartum women, despite no statistical differences observed between IO and EO in these groups. No significant differences between groups were observed for contractile function, showing the TrA greater values, followed by IO and EO in both nulliparous and postpartum women. CONCLUSIONS: This study suggests that the thickness (and the thickness pattern) of the abdominal muscles in women at 6 months postpartum differs from nulliparous, while for the lumbar muscles, it is comparable to nulliparous. However, despite the obliques being thinner in postpartum women, the abdominal muscles are functionally competent. IMPACT: This is believed to be the first study to compare abdominal and lumbar muscles thickness and contractile function specifically between primiparous and multiparous women. Although at 6 months' postpartum abdominal thickness differs from nulliparous women, these muscles are functionally competent. These findings provide valuable insights for use in the development of postpartum interventions.

Defected photonic crystal as propylene glycol THz sensor using parity-time symmetry.

Detecting unsafe levels of chemical gases and vapors is essential in improving and maintaining a healthy environment for all to enjoy. Propylene glycol is a colorless, synthetic gas commonly used in medications, fragrances, and cosmetics. It causes side effects such as headaches, lightheadedness, nausea, and fainting. So, monitoring of propylene glycol is critically vital. This study uses a defected photonic crystal as a propylene glycol THz sensor. Due to the high absorption of propylene glycol, the intensity of the resonant confined mode is very small. As a result, the performance of the designed sensor seems unsatisfactory. We will use parity-time symmetry for the first time in THz to magnify the resonant confined mode to detect propylene glycol. The effect of microcavity thickness, incident angle, and gain/loss factor will be studied. The optimized sensor recorded distinguished results compared to other studies for the detection of propylene glycol.

Gender Parity Among Vascular Surgeons: Progress and Attrition.

INTRODUCTION: Improving representation of women in medicine and surgery has been tempered by higher rates of attrition from residencies and from academic medicine among women compared to men. The attrition of women from the practicing vascular surgery workforce has not been studied. METHODS: We utilized the Center for Medicare and Medicaid Services' Doctors and Clinicians database to study vascular surgery employment patterns from 2015 to 2022. We examined gender balance within the workforce and attrition rates among male and female vascular surgeons. We utilized a logistic regression to calculate the odds of attrition by gender. RESULTS: The percentage of female vascular surgeons grew from 11% to 16% between 2015 and 2022, with each graduating class since 2005 having between 20% and 38% women. Yet, female surgeons were 2.05 (95% confidence interval: 1.36-3.08) times more likely to leave practice than their male counterparts when controlling for graduation year and practice in academic medicine. CONCLUSIONS: The proportion of women in vascular surgery is increasing as more women graduate into the specialty. Despite increasing representation, women are more likely than men to leave the workforce.

Strong Laser Emission Modulation by Coherent Perfect Absorption Inside Complex-Coupled Distributed Feedback Laser Diodes.

The proof-of-concept of the exploitation of Coherent Perfect Absorption (CPA) in electrically-injected distributed-feedback laser sources is reported. Capitalizing on the essence of CPA as "light extinction by light", an integrated laser-modulator scheme emerges. The key ingredient compared to conventional single-frequency laser diodes is a careful periodic in-phase modulation of both real and imaginary parts of the complex grating index profile that enables both single-frequency operation and 40 dB line purity at the Bragg frequency. It is shown that this combination is most apt for the operation of CPA as a modulation mechanism that respects the laser spectral purity. The specific proof-of-concept is based on an ultra-short external cavity formed by a metallic micro-mirror, whose role is to generate the second beam of more conventional CPA interferometric approaches. The implemented complex-coupled grating is compatible with existing industrial technologies and promising for real-life laser source applications. Furthermore, the concept can be directly transferred to other material platforms and other wavelengths ranging from terahertz to ultraviolet.

Period Poverty: How School Nurses Can Support Menstrual Health and Hygiene.

Lack of access to menstrual products, menstrual hygiene, and education, also known as period poverty, is a widespread issue and disproportionately impacts low-income, rural, Black, Latinx, Indigenous, and People of Color. Period poverty along with period symptoms, such as heavy and painful periods, contribute to school absenteeism impacting school connectedness and student success. The purpose of this article is to bring awareness to period poverty and encourage school nurses to intervene in individual schools, communities, and far-reaching policy spaces utilizing their expertise to secure resources. School nurses can assist in implementing interventions throughout the school year to increase student engagement, success, and overall menstrual health wellness. Through added engagement of stakeholders such as student groups, school staff and administrators, and community organizations, school nurses can help shift the narrative from a position of oppression around menstrual health to a position of empowerment.

PELMI: Realize robust DNA image storage under general errors via parity encoding and local mean iteration.

DNA molecules as storage media are characterized by high encoding density and low energy consumption, making DNA storage a highly promising storage method. However, DNA storage has shortcomings, especially when storing multimedia data, wherein image reconstruction fails when address errors occur, resulting in complete data loss. Therefore, we propose a parity encoding and local mean iteration (PELMI) scheme to achieve robust DNA storage of images. The proposed parity encoding scheme satisfies the common biochemical constraints of DNA sequences and the undesired motif content. It addresses varying pixel weights at different positions for binary data, thus optimizing the utilization of Reed-Solomon error correction. Then, through lost and erroneous sequences, data supplementation and local mean iteration are employed to enhance the robustness. The encoding results show that the undesired motif content is reduced by 23%-50% compared with the representative schemes, which improves the sequence stability. PELMI achieves image reconstruction under general errors (insertion, deletion, substitution) and enhances the DNA sequences quality. Especially under 1% error, compared with other advanced encoding schemes, the peak signal-to-noise ratio and the multiscale structure similarity address metric were increased by 10%-13% and 46.8%-122%, respectively, and the mean squared error decreased by 113%-127%. This demonstrates that the reconstructed images had better clarity, fidelity, and similarity in structure, texture, and detail. In summary, PELMI ensures robustness and stability of image storage in DNA and achieves relatively high-quality image reconstruction under general errors.

Genomic compliance with Chargaff's second parity rule may have originated non-adaptively, but stem-loops now function adaptively.

Of Chargaff's four rules on DNA base quantity, his second parity rule (PR-2) is the most contentious. Various biometricians (e.g., Sueoka, Lobry) regarded PR-2 compliance as a non-adaptive feature of modern genomes that could be modeled through interrelations among mutation rates. However, PR-2 compliance with stem-loop potential was considered adaptively relevant by biochemists familiar with analyses of nucleic acid structure (e.g., of Crick) and of meiotic recombination (e.g., of Kleckner). Meanwhile, other biometricians had shown that PR-2 complementarity extended beyond individual bases (1-mers) to oligonucleotides (k-mers), possibly reflecting "advantageous DNA structure" (Nussinov). An "introns early" hypothesis (Reanney, Forsdyke) had suggested a primordial nucleic acid world with recombination-mediated error-correction requiring genome-wide stem-loop potential to have evolved prior to localized intrusions of protein-encoding potential (exons). Thus, a primordial genome was equivalent to one long intron. Indeed, when assessed as the base order-dependent component (correcting for local influences of GC%), modern genes, especially when evolving rapidly under positive Darwinian selection, display high intronic stem-loop potential. This suggests forced migration from neighboring exons by competing protein-encoding potential. PR-2 compliance may have first arisen non-adaptively. Primary prototypic structures were later strengthened by their adaptive contribution to recombination. Thus, contentious views may actually be in harmony.

Effect of surgeon-patient sex discordance on ventral hernia repair outcomes.

PURPOSE: Concordance is an important dimension of the physician-patient relationship that may be linked to health care disparities. The purpose of this study was to determine if sex discordance between surgeon and patient impacts surgical outcomes. METHODS: A retrospective review of prospectively collected data obtained from the Abdominal Core Health Quality Collaborative (ACHQC) registry was performed on all patients who underwent ventral hernia repair. Surgical site occurrences (SSO), surgical site infections (SSI), surgical site occurrence requiring procedural intervention (SSOPI) and 30-day readmission rates were recorded. RESULTS: Female patients operated on by male surgeons have increased odds of having an SSI/SSO (OR 1.099, 95% CI 1.022-1.181), SSOPI (OR 1.156, 95% CI 1.031-1.297), and readmission (OR 1.259, 95% CI 1.128-1.406) when compared to male patients operated on by male surgeons. There was no significant difference in adverse outcomes between patient groups when operated on by female surgeons. CONCLUSION: Sex discordance between surgeon and patient is associated with increased odds adverse outcomes when male surgeons operate on female patients.

Comparison of Cranial Cruciate Ligament Rupture Incidence among Parous and Nulliparous Rottweiler Bitches: Evidence from a Lifetime Cohort Study Supporting a Paradigm of Pregnancy-Associated Protection against Subsequent Non-Reproductive Disease Outcomes.

Emerging evidence in women supports the notion that pregnancy may reset disease resistance, thereby providing protection against subsequent adverse health outcomes, but this hypothesis has not been adequately explored in domestic dogs. Cranial cruciate ligament (CCL) rupture is a degenerative orthopedic disease that frequently affects pet dogs, and its risk has been associated with disruption of the reproductive hormone axis. Our research team is conducting a lifetime cohort study of purebred Rottweilers in North America that have lived 30% longer than breed-average. Detailed medical and reproductive histories of 33 nulliparous and 32 parous Rottweilers were generated from questionnaires and review of medical records. Interviews with owners of bitches in the nulliparous group served to limit selection bias, confirming that in no instance was the reason for nulliparity based upon the owner's suspicion that a bitch had a heightened risk for CCL rupture. The risk of CCL rupture associated with parity and other exposure variables was estimated using multivariate logistic regression. Overall, CCL rupture was diagnosed in 17 of 65 (26%) bitches. Median age at first litter and CCL rupture were 3.6 and 6.5 years, respectively. Compared to nulliparous, parous bitches had a significant 94% reduction in CCL rupture risk adjusted for duration of ovary exposure, overweight body condition, dietary pattern, habitual physical activity, and work/sport activity [ORadjusted (95% CI) = 0.06 (0.01-0.46); (p = 0.006)]. The observed parity-associated CCL rupture risk reduction remained robust in sensitivity analysis excluding six nulliparous bitches for which decision not to breed was based on diagnosis of hip or elbow dysplasia, conditions which may be genetically linked to CCL rupture [ORadjusted (95% CI) = 0.08 (0.01-0.58); (p = 0.01)]. This work sets the stage for replication studies in other canine populations that should begin to explore the mechanistic basis for parity-associated CCL rupture risk reduction and to pursue other non-reproductive health outcomes in bitches whose incidence or severity may be parity-sensitive.

A synthetic review: natural history of amniote reproductive modes in light of comparative evolutionary genomics.

There is a current lack of consensus on whether the ancestral parity mode was oviparity (egg-laying) or viviparity (live-birth) in amniotes and particularly in squamates (snakes, lizards, and amphisbaenids). How transitions between parity modes occur at the genomic level has primary importance for how science conceptualises the origin of amniotes, and highly variable parity modes in Squamata. Synthesising literature from medicine, poultry science, reproductive biology, and evolutionary biology, I review the genomics and physiology of five broad processes (here termed the 'Main Five') expected to change during transitions between parity modes: eggshell formation, embryonic retention, placentation, calcium transport, and maternal-fetal immune dynamics. Throughout, I offer alternative perspectives and testable hypotheses regarding proximate causes of parity mode evolution in amniotes and squamates. If viviparity did evolve early in the history of lepidosaurs, I offer the nucleation site hypothesis as a proximate explanation. The framework of this hypothesis can be extended to amniotes to infer their ancestral state. I also provide a mechanism and hypothesis on how squamates may transition from viviparity to oviparity and make predictions about the directionality of transitions in three species. After considering evidence for differing perspectives on amniote origins, I offer a framework that unifies (i) the extended embryonic retention model and (ii) the traditional model which describes the amniote egg as an adaptation to the terrestrial environment. Additionally, this review contextualises the origin of amniotes and parity mode evolution within Medawar's paradigm. Medawar posited that pregnancy could be supported by immunosuppression, inertness, evasion, or immunological barriers. I demonstrate that this does not support gestation or gravidity across most amniotes but may be an adequate paradigm to explain how the first amniote tolerated internal fertilization and delayed egg deposition. In this context, the eggshell can be thought of as an immunological barrier. If serving as a barrier underpins the origin of the amniote eggshell, there should be evidence that oviparous gravidity can be met with a lack of immunological responses in utero. Rare examples of two species that differentially express very few genes during gravidity, suggestive of an absent immunological reaction to oviparous gravidity, are two skinks Lampropholis guichenoti and Lerista bougainvillii. These species may serve as good models for the original amniote egg. Overall, this review grounds itself in the historical literature while offering a modern perspective on the origin of amniotes. I encourage the scientific community to utilise this review as a resource in evolutionary and comparative genomics studies, embrace the complexity of the system, and thoughtfully consider the frameworks proposed.

Maternal and Perinatal Outcomes in Pregnant Women with Heart Disease: A Case-Control Study.

Objective: We analyzed the obstetric and cardiac characteristics and results of pregnant women with heart disease (HD) and compared their results with those of healthy controls. Methods: In this retrospective single-center case-control study, women with HD attended between 2010 and 2018 were matched at a 1:2 ratio (according to date of delivery, parity, and singleton or twin pregnancy) with controls without heart disease treated in the same referral center. Results: We identified 141 pregnant women with HD, of whom 132 reached 22 weeks of gestation and were paired with 264 healthy controls, for a total of 396 participants and 408 newborns. Most common HDs were congenital HD (53 women), arrhythmia (46), valvular HD (35), and cardiomyopathy (16), having women with more than one coexisting HD. During pregnancy or the puerperium, 19.9% of mothers experienced a major adverse cardiac event (MACE), with 5% requiring intensive care unit (ICU) admission. The rates of cesarean section were 37.1% in the case group and 18.2% in the control group, with an odds ratio (OR) of 2.66 (95% CI = 1.66-4.26, p < 0.001). We also found a higher use of general anesthesia, with an OR of 10.73 (95% CI = 2.32-49.75, p = 0.002); more prolonged hospitalizations, with an OR of 2.91 (95% CI 1.02-8.35, p = 0.023); and a higher incidence of low neonatal weight, with an OR of 1.96 (95% CI 1.09-3.52, p = 0.012). There were no differences between groups in terms of gestational age at delivery; however, we observed greater prematurity in women with HD, without reaching statistical significance. The rate of congenital heart disease among the newborns of mothers with HD was 13.2%. Conclusions: HD increases maternal morbidity during pregnancy and it is associated with higher rates of cesarean section and low birth weight.

Peripartum Subtotal Hysterectomy in Multifetal Gestation.

Peripartum hysterectomy (PH) is usually undertaken in cases of life-threatening obstetric haemorrhage to prevent the death of the mother. Obstetric haemorrhage, a leading indication for PH, is a major cause of maternal deaths globally, particularly in regions with limited access to advanced medical care. The cause of the per vaginal bleeding was due to the patient in labour with a cervical stitch, and immediate action was taken in the form of a lower segment caesarean section. After the patient's abdominal drain is noticed with fresh blood collection, an emergency obstetric hysterectomy is done.

Estimation of the Impulse Response of the AWGN Channel with ISI within an Iterative Equalization and Decoding System That Uses LDPC Codes.

In this paper, new schemes have been proposed for the estimation of the additive white Gaussian noise (AWGN) channel with intersymbol interference (ISI) in an iterative equalization and decoding system using low-density parity check (LDPC) codes. This article explores the use of the least squares algorithm in various scenarios. For example, the impulse response of the AWGN channel h was initially estimated using a training sequence. Subsequently, the impulse response was calculated based on the training sequence and then re-estimated once using the sequence estimated from the output of the LDPC decoder. Lastly, the impulse response was calculated based on the training sequence and re-estimated twice using the sequence estimated from the output of the LDPC decoder. Comparisons were made between the performances of the three mentioned situations, with the situation in which a perfect estimate of the impulse response of the channel is assumed. The performance analysis focused on how the bit error rate changes in relation to the signal-to-noise ratio. The BER performance comes close to the scenario of having a perfect estimate of the impulse response when the estimation is performed based on the training sequence and then re-estimated twice from the sequence obtained from the output of the LDPC decoder.

Changes in the metabolomic profiles of mammary secretion in relation to dam litter size and parity number in Black Bengal goats.

Background and Aim: The colostrum is essential for a kid's survival and development. The metabolomic profiles of mammary secretion in goats are limited. This study investigated the metabolomic profiles of mammary secretion in purebred Black Bengal goats and their relationships with litter size and parity number. Materials and Methods: 500 MHz nuclear magnetic resonance was used to analyze the metabolomic profiles of 43 colostrum and milk samples collected on delivery day and day 7 after parturition, respectively. Results: Fifty-one metabolites were distinguished between colostrum and milk based on heatmap visualization and hierarchical cluster analysis. In colostrum, most compounds were present in significantly greater amounts than in milk. Milk of goats with multiple litter sizes had higher levels of lactose while fat, protein, total solids, solid not fat, and most of the metabolites were lower. The parity number of dams shows no difference in the composition of all components between primiparous and multiparous goats. Conclusion: The components in colostrum were significantly more concentrated than those in milk. The multiple litter sizes in dams led to a significant impact on the composition of lactose and other milk metabolites.

Lifestyle and metabolic factors affect risk for meningioma in women: a prospective population-based study (The Cohort of Norway).

Background: Meningioma is the most common primary brain tumor, with a clear preponderance in women. Obesity is considered a risk factor for the development of meningioma. Obesity is also the clinical hallmark of metabolic syndrome, characterized by glucose intolerance, dyslipidemia, and hypertension. Lifestyle and metabolic factors directly impact overweight and obesity and are therefore potential risk factors for meningioma development. The aim of this study is to assess lifestyle and metabolic factors for meningioma risk in women. Methods: The Cohort of Norway (CONOR) is a nationwide health survey, conducted between 1994 and 2003, including anthropometric measures, blood tests, and health questionnaires. Linkage to the National Cancer Registry enabled the identification of intracranial meningioma during follow-up until December 2018. Results: A total of 81,652 women were followed for a combined total of 1.5 million years, and 238 intracranial meningiomas were identified. Increasing levels of physical activity (HR 0.81; 95% CI 0.68-0.96; p trend <0.02) and parity (HR 0.83; 95% CI 0.71-0.97; p trend <0.03) were negatively associated with meningioma risk. Diabetes mellitus or glucose intolerance increased the risk for meningioma (HR 2.54; 95% CI 1.60-4.05). Overweight and obesity were not associated with meningioma risk, nor was metabolic syndrome. However, participants without metabolic dysfunction had a reduced meningioma risk, while participants with all five metabolic factors present had a 4-fold risk increase for meningioma (HR 4.28; 95% CI 1.34-13.68). Conclusion: Lifestyle factors seem to significantly influence meningioma risk. However, disentangling the complex associations and interactions between factors for meningioma risk will be a challenging task for future studies.

Association of parity with the timing and type of menopause: A longitudinal cohort study.

We investigated the time-varying association between parity and timing of natural menopause, surgical menopause, and premenopausal hysterectomy among 23,728 women aged 40-65 years at enrollment in the Alberta's Tomorrow Project cohort study (2000-2022), using flexible parametric survival analysis. Overall, natural menopause was most common by study end (57.2%), followed by premenopausal hysterectomy (11.4%) and surgical menopause (5.3%). Risks of natural menopause before age 50 years were elevated for 0 births (adjusted hazard ratio at age 45: 1.33, 95% CI 1.18-1.49) and 1 birth (age 45: 1.21, 1.07-1.38), but similar for ≥3 births (age 45: 0.95, 0.85-1.06), compared to 2 births (reference). Elevated risks of surgical menopause before age 45 years for 0 births (age 40: 1.37, 1.09-1.69) and 1 birth (age 40: 1.11, 0.85-1.45) attenuated when excluding women with past infertility or recurrent pregnancy loss, and reduced risks were observed over time for ≥3 births (age 50: 0.84, 0.75-0.94). Risks of premenopausal hysterectomy were lower before age 50 years for 0 births (age 45: 0.82, 0.76-0.88) but elevated after age 40 years for ≥3 births (age 50: 1.25, 1.08-1.45). These complex associations necessitate additional research on the sociobiological impacts of childbearing on gynecologic health.

Improving radiological quantification of levator hiatus features with measures informed by statistical shape modeling.

Purpose: The measures that traditionally describe the levator hiatus (LH) are straightforward and reliable; however, they were not specifically designed to capture significant differences. Statistical shape modeling (SSM) was used to quantify LH shape variation across reproductive-age women and identify novel variables associated with LH size and shape. Approach: A retrospective study of pelvic MRIs from 19 nulliparous, 32 parous, and 12 pregnant women was performed. The LH was segmented in the plane of minimal LH dimensions. SSM was implemented. LH size was defined by the cross-sectional area, maximal transverse diameter, and anterior-posterior (A-P) diameter. Novel SSM-guided variables were defined by regions of greatest variation. Multivariate analysis of variance (MANOVA) evaluated group differences, and correlations determined relationships between size and shape variables. Results: Overall shape ( p < 0.001 ), SSM mode 2 (oval to T -shape, p = 0.002 ), mode 3 (rounder to broader anterior shape, p = 0.004 ), and maximal transverse diameter ( p = 0.003 ) significantly differed between groups. Novel anterior and posterior transverse diameters were identified at 14% and 79% of the A-P length. Anterior transverse diameter and maximal transverse diameter were strongly correlated ( r = 0.780 , p < 0.001 ), while posterior transverse diameter and maximal transverse diameter were weakly correlated ( r = 0.398 , p = 0.001 ). Conclusions: The traditional maximal transverse diameter generally corresponded with SSM findings but cannot describe anterior and posterior variation independently. The novel anterior and posterior transverse diameters represent both size and shape variation, can be easily calculated alongside traditional measures, and are more sensitive to subtle and local LH variation. Thus, they have a greater ability to serve as predictive and diagnostic parameters.

Investigating the influence of oral contraceptive pill use on multiple sclerosis risk using UK Biobank data.

OBJECTIVE: To investigate the association between oral contraceptive (OC) pill use and the risk of developing multiple sclerosis (MS), attempting to address the limitations present in previous studies that produced conflicting results. DESIGN: A population-based cohort study using data from the UK Biobank. PATIENTS: The study included 181,058 women of white ethnicity born in England between 1937 and 1970, among which 1,131 had an MS diagnosis. INTERVENTION: Oral contraceptive use, considering the self-reported age of initiation and discontinuation. The exposures of interest include the following: ever-use, current use, duration of current use in years, and age and year at initiation. MAIN OUTCOME MEASURES: Multiple sclerosis diagnosis (International Classification of Disease, 10th revision: G35) was used as an outcome of interest, and the associations with the exposures of interest were investigated using marginal structural models with a time-to-event approach. To adjust for confounding, we included in the models several variables, including MS polygenic risk score, education level, parity, smoking, fertility problems, obesity, and mononucleosis. We further aimed to evaluate the influence of parity using a mediation analysis. RESULTS: The association of both ever and current OC use did not result in a statistically significant MS hazard increase (ever vs. never-users, hazard ratio [HR] = 1.30 [95% confidence interval {CI}: 0.93,1.82]; current vs. never-users, HR = 1.35 [95% CI: 0.81, 2.25]). However, we highlighted parity as an effect modifier for this association. In nulliparous women, ever and current use resulted in a significant twofold and threefold MS hazard increase (HR = 2.08 [95% CI: 1.04, 4.17] and HR = 3.15 [95% CI: 1.43, 6.9]). These associations were supported by significant MS hazard increases for a higher duration of current use and for an earlier age at initiation. We further highlighted genetic MS susceptibility as another effect modifier, as a stronger OC-MS hazard association was found in women with a low MS polygenic risk score. CONCLUSION: Our findings highlighted how the association between OC use and MS varies on the basis of individual characteristics such as parity and genetic MS susceptibility. Importantly, current use in nulliparous women was found to be associated with a threefold increase in MS hazard. We acknowledge the need for cautious causal interpretation and further research to validate these findings across diverse populations and OC types.

Pregnancy history and estradiol influence spatial memory, hippocampal plasticity, and inflammation in middle-aged rats.

Pregnancy and motherhood can have long-term effects on cognition and brain aging in both humans and rodents. Estrogens are related to cognitive function and neuroplasticity. Estrogens can improve cognition in postmenopausal women, but the evidence is mixed, partly due to differences in age of initiation, type of menopause, dose, formulation and route of administration. Additionally, past pregnancy influences brain aging and cognition as a younger age of first pregnancy in humans is associated with poorer aging outcomes. However, few animal studies have examined specific features of pregnancy history or the possible mechanisms underlying these changes. We examined whether maternal age at first pregnancy and estradiol differentially affected hippocampal neuroplasticity, inflammation, spatial reference cognition, and immediate early gene activation in response to spatial memory retrieval in middle-age. Thirteen-month-old rats (who were nulliparous (never mothered) or previously primiparous (had a litter) at three or seven months) received daily injections of estradiol (or vehicle) for sixteen days and were tested on the Morris Water Maze. An older age of first pregnancy was associated with impaired spatial memory but improved performance on reversal training, and increased number of new neurons in the ventral hippocampus. Estradiol decreased activation of new neurons in the dorsal hippocampus, regardless of parity history. Estradiol also decreased the production of anti-inflammatory cytokines based on age of first pregnancy. This work suggests that estradiol affects neuroplasticity and neuroinflammation in middle age, and that age of first pregnancy can have long lasting effects on hippocampus structure and function.