Search Results (653)

Background and Objectives: The rising rate of caesarean sections worldwide has led to an increasing number of women facing the choice between a trial of labor after caesarean section and elective repeat caesarean delivery. A uterine rupture is the most serious complication of trial of labor after caesarean section and, from a medical point of view, the main reason for an elective repeat caesarean section. Previous studies on the predictive value of lower uterine segment thickness have shown inconsistent results. Conversely, it is unclear what characteristics of the uterotomy site allow for an uncomplicated vaginal birth, even in the presence of defective healing. This study aimed to evaluate the sonographic features of the lower uterine segment in the early postpartum period after successful vaginal birth after caesarean section. Materials and Methods: We conducted a single-center observational cohort study including 30 women after vaginal birth after caesarean section. Transabdominal and transvaginal sonography were performed within the first days postpartum. Measurements included residual myometrial thickness, defect dimensions, and healing ratio after delivery to perform an ex-post analysis with regard to successful vaginal birth. Descriptive statistics were applied. Results: Transabdominal ultrasound (TAS) visualized the uterotomy in 90.0% of patients (27/30), with a median residual myometrial thickness of 12.0 mm (interquartile range 8.0–19.0). Among these, a uterine defect ≥ 2 mm was present in 63.0% (17/27 of visualized cases; 56.7% [17/30] of the entire cohort). Transvaginal ultrasound (TVS) visualized the uterotomy in all patients (29/29), with a median residual myometrial thickness of 9.9 mm (interquartile range 7.5–14.5); a defect was present in 82.8% (24/29 of visualized cases; 80.0% [24/30] of the entire cohort), with a median depth of 9.9 mm (interquartile range 6.5–15.6). Conclusions: Early postpartum sonographic evaluation of the uterotomy scar after vaginal birth after caesarean section frequently reveals even large sonographic uterine wall defects. This study design is not suitable for predicting uncomplicated vaginal delivery, but it demonstrates for the first time—on a retrospective basis—that even large defects in the anterior uterine wall are compatible with an uncomplicated vaginal birth after caesarean section. Full article

Background/Objectives: Single atrium is a rare congenital heart defect typically repaired in infancy. Unrepaired adults with pregnancy face high risk, and postpartum repair with delayed sternal closure (DSC) has rarely been reported. Methods: We present a 33-year-old multiparous woman who presented at 30 weeks + 1 day of gestation with progressive dyspnea. Transthoracic echocardiography (TTE) revealed a single atrium with a common atrioventricular valve and an estimated pulmonary artery systolic pressure (PASP) of 47 mmHg. The multidisciplinary team advised early cesarean section, which was performed at 30 weeks + 3 days of gestation, but postpartum symptoms persisted. Six months later, the patient underwent surgical correction. The procedure was converted from right subaxillary mini-thoracotomy to median sternotomy due to intraoperative aortic dissection, which was repaired. The single atrium was partitioned using a bovine pericardial patch. Due to myocardial edema and hemodynamic instability, the sternum was left open and closed on postoperative day 4. She required 8 days of mechanical ventilation and 13 days of intensive care, and was discharged on day 27. Results: Surgical repair was successful, and at the 6-month postoperative follow-up, she had achieved NYHA class I functional status, with an estimated PASP of 40 mmHg and a well-positioned baffle with no residual shunt. Conclusions: This case demonstrates that multidisciplinary collaboration is essential for pregnant patients with unrepaired congenital heart disease, postpartum surgical correction is feasible with careful perioperative planning, and DSC is a safe strategy for managing hemodynamic instability in complex cardiac cases. Full article

Background/Objectives: Adolescent pregnancy is associated with an increased risk of adverse perinatal outcomes; however, its hematological characteristics remain incompletely understood. The aim of this study was to compare antepartum and postpartum complete blood count (CBC) parameters together with hemogram-derived inflammatory indices in adolescent and adult pregnancies and to investigate their associations with maternal and neonatal outcomes. Methods: This retrospective comparative cohort study included 428 singleton pregnancies comprising 205 adolescent (14–17 years) and 223 adults (18–42 years). Antepartum blood samples were obtained at admission for delivery, whereas postpartum samples were collected approximately six hours after delivery according to the institutional practice. CBC parameters (including neutrophil, lymphocyte, monocyte, and platelet counts) were recorded, and hemogram-derived inflammatory indices, including neutrophil-to-lymphocyte ratio (NLR), Platelet-to-lymphocyte ratio (PLR), systemic immune-inflammation index (SII), systemic inflammation response index (SIRI), aggregate index of systemic inflammation (AISI), and systemic inflammation-monocyte index (SIMI), were subsequently calculated. Comparisons were adjusted for gestational age at sampling and parity using a prespecified non-redundant marker set, and multiple testing was controlled using the Benjamini-Hochberg false discovery rate procedure. Multivariable logistic regression and machine-learning analyses were performed to evaluate associations with adverse maternal and neonatal outcomes. Results: Adolescent pregnancies demonstrated significantly higher antepartum neutrophil and monocyte counts than adult pregnancies (q < 0.05), and these differences remained significant after adjustment for gestational age at sampling and parity (both q < 0.01), whereas differences in hemoglobin and platelet counts were no longer significant (both q = 0.138). Low birth weight (10.2% vs. 4.5%), neonatal intensive care unit admission (15.1% vs. 8.5%), composite adverse outcome (22.9% vs. 15.2%), and birth weight below the 10th percentile (14.7% vs. 8.0%) were numerically more frequent among adolescents but were not statistically significant after false discovery rate correction (all q > 0.05). Across 30 prespecified marker–outcome associations, none remained significant after false discovery rate correction. Antepartum neutrophil count was not independently associated with low birth weight after multivariable adjustment (OR 1.233, 95% CI 0.858–1.737; p = 0.248, q = 0.413). Exploratory machine-learning models demonstrated only modest discrimination, with the highest cross-validated AUC of approximately 0.60, and did not outperform conventional regression models. Conclusions: Adolescent pregnancy was associated with higher neutrophil and monocyte counts during both the antepartum and postpartum periods, reflecting modest differences in hematological profile rather than an independently predictive inflammatory profile. These hematological differences were not independently associated with adverse maternal or neonatal outcomes after adjustment for confounding factors and correction for multiple testing. Hemogram-derived inflammatory indices should therefore be interpreted as mathematical transformations of routine CBC parameters rather than biologically independent biomarkers. Because blood samples were obtained at admission for delivery, these findings characterize the peripartum inflammatory profile and should not be interpreted as evidence of early pregnancy risk prediction. Full article

Background/Objectives: Food insecurity has been associated with adverse eating patterns, which increase the risk for overweight and obesity. However, most studies measure food insecurity and eating behaviors cross-sectionally, not assessing whether experiencing food insecurity over time influences eating behaviors. Therefore, this study assessed the relationship between cumulative food insecurity and food approach and food avoidance eating behaviors and evaluated the effect of breastfeeding intensity and duration on this relationship. Methods: The Study of Women, Infant Feeding and Type 2 Diabetes after Gestational Diabetes Pregnancy (SWIFT) is a prospective longitudinal cohort of 1033 mothers diagnosed with gestational diabetes and their youth. Breastfeeding intensity and duration were assessed at research visits and through mailed monthly surveys from birth to one year postpartum. The SWIFT study in Youth (SWIFT-Y) was a cohort of 701 SWIFT offspring that consented to participate in a research visit 11–16 years postpartum. Youth’s BMI was measured at 11–16 years old through a research visit or their electronic health record. At each of the four research visits (6–9 weeks, one year, two years, and 11–16 years postpartum), participants were categorized as being food secure (0) or food insecure (1). Scores across the four visits were summed (range 0–4), reflecting the number of assessments one was classified as food insecure. The Child Eating Behavior Questionnaire was used to measure the prevalence of eight eating behaviors in the youth, with higher scores indicating that the behaviors were more apparent. According to the measure, the behaviors were categorized into two groups: food approach and food avoidance. Food approach consists of youth’s food responsiveness, emotional overeating, enjoyment of food, and desire to drink, and has been positively associated with a child’s BMI. Food avoidance includes the youth’s satiety responsiveness, slowness in eating, emotional undereating, and food fussiness, and is negatively associated with BMI. Linear regressions assessed whether cumulative food insecurity was associated with eating patterns, and exploratory analysis analyzed whether this relationship differed by breastfeeding duration (<six months, ≥six months) and intensity (exclusive, not exclusive), controlling for the child’s BMI and sociodemographic characteristics. Results: In this complete-case secondary analysis (n = 321), each additional experience of food insecurity was associated with a higher food approach score (B = 0.30, 95% CI [0.04, 0.57], p = 0.03), but not food avoidance (B = −0.03, 95% CI [−0.21, 0.15], p = 0.74). These results varied by breastfeeding duration (B = −0.74, p = 0.001), as the relationship remained significant among those who were breastfed for <six months (B = 0.73, p < 0.001) but was attenuated among those who were breastfed for ≥six months (B = −0.26, p = 0.18). Conclusions: Experiencing food insecurity more during childhood is associated with adverse eating patterns at 11–16 years old. However, breastfeeding for ≥six months influenced this relationship, suggesting that early-life feeding may impact the effect of food insecurity on one’s eating behaviors later in life. Full article

Background/Objectives: Preeclampsia is associated with endothelial dysfunction and neurological morbidity. Non-invasive ocular imaging may offer insight into subclinical ocular changes associated with neurological involvement. This prospective single-center pilot study evaluated retinal nerve fiber layer (RNFL) thickness, optic nerve sheath diameter (ONSD), and angiogenic biomarkers in women with and without preeclampsia across the peripartum period. Methods: Pregnant women with preeclampsia and normotensive controls were enrolled at a tertiary center. RNFL thickness was assessed by optical coherence tomography and ONSD by transbulbar ultrasound at three predefined visits: antepartum, early postpartum, and late postpartum. The soluble fms-like tyrosine kinase-1/placental growth factor (sFlt-1/PlGF) ratio was determined at the antepartum visit. Group comparisons, longitudinal changes, and exploratory correlations were analyzed, with paired-eye dependence addressed using generalized estimating equations (GEE). Results: Thirty-eight women were included; after reclassification of three controls who developed preeclampsia, 15 women were analyzed in the preeclampsia group and 23 in the control group. RNFL thickness was numerically higher in women with preeclampsia across visits; GEE analyses accounting for paired-eye measurements showed exploratory between-group differences at the early postpartum visit. ONSD did not differ significantly between groups, and no participant had a bilateral mean ONSD > 5.8 mm. No significant between-group differences in longitudinal change from early to late postpartum were observed. Exploratory analyses did not demonstrate a consistent association between the sFlt-1/PlGF ratio and the imaging parameters. Conclusions: RNFL thickness was numerically higher in women with preeclampsia, whereas ONSD showed no clear separation between groups. The findings remain exploratory and do not establish a diagnostic or prognostic role for either imaging parameter. Larger prospective studies are needed to determine the clinical relevance of non-invasive ocular imaging in preeclampsia. Full article

Maternal rejection is an uncommon postpartum behavioral disorder in mares that may compromise colostrum intake, mare–foal successful nursing acceptance, and neonatal survival. This retrospective observational study described the clinical presentation, therapeutic management, and short-term outcome of 27 mares diagnosed with maternal rejection between September 2023 and June 2026 in western Romania. Data regarding breed, parity, parturition, behavioral presentation, treatment, supportive management, time to maternal acceptance, and outcome were extracted from medical records. Associations between categorical variables were evaluated using Fisher’s exact test, while differences in time to acceptance were assessed using the Mann–Whitney U test. Primiparous mares represented 59.3% of cases, and obstetrical complications occurred in 48.1%. Aggressive behavior was the predominant presentation. Primiparous mares exhibited aggressive forms of rejection significantly more frequently than multiparous mares (p = 0.006) and required a significantly longer interval before maternal acceptance (median: 38 h versus 21 h; U = 117.0, p = 0.010). Oxytocin was the most frequently administered medication, and behavioral management accompanied pharmacological treatment in most cases. Maternal acceptance was achieved in 24 of 27 mares (88.9%). Early recognition and individualized multimodal management may contribute to favorable short-term outcomes. Full article

Background: The Baby-Friendly Hospital Initiative (BFHI), developed by the World Health Organization (WHO) and UNICEF, provides an evidence-based framework to protect, promote, and support breastfeeding through implementation of the Ten Steps to Successful Breastfeeding. Despite its global adoption, implementation and scale-up of BFHI remain inconsistent across healthcare systems. In Saskatchewan, Canada, only one healthcare facility currently holds BFHI designation, highlighting the need to understand the health system factors influencing implementation. This study aimed to explore the barriers and facilitators influencing the implementation and scale-up of BFHI within Saskatchewan healthcare settings. Methods: A qualitative descriptive study was conducted using Bronfenbrenner’s socioecological model as a guiding theoretical framework. Semi-structured interviews were conducted with 26 mothers and healthcare professionals with breastfeeding-related experiences in Saskatchewan, including 11 mothers (42.3%), 6 mothers who were also healthcare professionals (23.1%), and 9 healthcare professionals without maternal experience (34.6%). Participants were recruited using purposive and maximum variation sampling. Guided by a socioecological framework, interview data were manually analyzed using an iterative thematic analysis approach. Themes were interpreted across individual, interpersonal, organizational, community, and health system levels. Results: Five interrelated themes characterized BFHI implementation and scale-up in Saskatchewan, including (1) leadership and governance as foundations for BFHI implementation; (2) workforce capacity, competency, and practice consistency as determinants of care delivery; (3) continuity of breastfeeding support across care settings; (4) breastfeeding as a psychosocially embedded maternal experience; and (5) structural and societal factors shaping BFHI scale-up. While supportive leadership, provincial breastfeeding guidelines, skilled healthcare providers, interdisciplinary collaboration, and community-based services facilitated BFHI-aligned care, implementation was challenged by workforce shortages, inconsistent clinical practices, limited access to specialized breastfeeding support, early postpartum discharge, geographic inequities, fragmented care pathways, and inadequate system-level monitoring. Conclusions: In Saskatchewan, BFHI implementation and scale-up are shaped by interconnected organizational, workforce, maternal, and structural factors. The findings provide context-specific qualitative evidence to inform future BFHI planning and implementation. Further research is needed to assess the feasibility, sustainability, and effectiveness of strategies to support BFHI scale-up across diverse healthcare and geographic settings. Full article

The transition period is a physiologically demanding stage in primiparous dairy cows, as the onset of lactation occurs simultaneously with continued growth. This longitudinal study initially enrolled 22 primiparous Holstein dairy cows. Eight cows that developed transition disorders during the monitoring period were excluded according to the predefined study protocol. Therefore, the final analysis included 14 clinically healthy primiparous Holstein dairy cows monitored from four weeks before calving to five weeks postpartum to characterize normal physiological adaptation during the transition period. Cows were monitored using continuous intraruminal sensors and automated milk analysis systems, while blood samples were collected weekly and analysed using linear mixed models with repeated measurements. Milk yield increased from 17.9 kg/day in week +1 to 26.3 kg/day in week +5 (a relative increase of 47%). Significant temporal changes were observed in iron (Fe), phosphorus (P), glucose (GLUC), triglycerides (TRIG), urea (UREA), albumin (ALB), and alanine aminotransferase (ALT). Serum Fe decreased from 30.9 µmol/L at week −2 to 14.5 µmol/L at week +2 (−53%), while P declined from 2.95 mmol/L at week +1 to 1.41 mmol/L at week +2 (−52%). Sensor data showed reduced physical activity (−59%) and increased water intake from 60.6 L/day in week −4 to 99.4 L/day in week +1, whereas rumination time and rumen pH remained relatively stable. Correlation analysis identified significant associations among milk yield, metabolic variables, and behavioural indicators. These findings suggest coordinated physiological adaptation during the transition period and support the use of combined blood and sensor-based monitoring to better understand early-lactation dynamics in primiparous dairy cows. Full article

Background: Maternal bonding is a key determinant of maternal and infant well-being, yet little is known about preconception factors that shape its development. Learned helplessness (LH), a stable cognitive vulnerability characterized by perceived uncontrollability and diminished efficacy, may predispose women to poorer maternal bonding. This study examined whether preconception LH predicts antenatal and postpartum bonding and whether this association is mediated by antenatal bonding and prenatal affective symptoms. Methods: A sample of 151 euthymic, nulliparous women was followed prospectively from preconception through pregnancy and postpartum, completing questionnaires assessing LH, depressive and anxiety symptoms, and antenatal and postpartum bonding. Analyses used structural equation modeling, linear mixed-effects models, hierarchical regression, and parallel mediation. Results: LH showed high stability from preconception to postpartum (r = 0.71), with no mean-level change, whereas affective symptoms increased. Antenatal bonding predicted postpartum bonding (β = 0.52, p < 0.001). Higher preconception LH predicted lower antenatal bonding (b = −0.20, p = 0.002) and lower postpartum bonding (b = −0.29, p < 0.001), beyond affective symptoms in the corresponding period. The LH–postpartum bonding association was partially mediated by antenatal bonding (β = −0.10, p = 0.005), but not by prenatal depression or anxiety symptoms. Conclusions: Preconception LH reflects a stable cognitive vulnerability linked to poorer maternal bonding. Its association with postpartum bonding was partly mediated by antenatal bonding, but not by prenatal affective symptoms, suggesting that LH’s relevance to postpartum bonding begins when the maternal bond develops during pregnancy. Assessing LH before conception or early in pregnancy may help identify vulnerability to lower bonding, beyond current affective symptoms. Full article

Several indicators are used in dairy farms to monitor health status during the puerperal period. Uterine disease complex is one of the compromised health issues during this period. This study mainly aims to evaluate the relationship between abnormal vaginal discharge scores (VDS), indicative of uterine health impairment (e.g., metritis), and reproductive and non-reproductive risk factors during the first three weeks postpartum of dairy cows. An ordinal logistic GLMM was used to evaluate the influence of vulvovaginal lacerations, fecal consistency, ketonuria, body condition, parity, day of reproductive evaluation and farm on normal (0–2 points; control group), moderate (3–4), and high (5–9) VDS from 2860 calvings in 14 Danish farms (2023–2025). Vulvar and vaginal lacerations (odds ratio, OR = 2.4 and 17.1, respectively; p < 0.001) and soft feces (OR = 1.7; p < 0.001), ketosis (OR = 1.8; p < 0.001), low body condition score (OR = 1.7; p < 0.01), and multiparous cows (OR = 2.1; p < 0.0001) were associated with moderate and high VDS. These results suggest that vulvovaginal lacerations, even if considered as a potential residual confounder regarding dystocia and other periparturient reproductive abnormalities, and non-reproductive factors, such as fecal consistency, should be included to assess uterine health during postpartum, regarding normal, moderate, and high VDS. A large study involving all relevant reproductive occurrences during puerperium and their impact on further fertility can provide additional information for reproductive herd health management. Full article

Infection by the varicella–zoster virus (VZV) during pregnancy is uncommon but clinically relevant, since it may compromise both the mother and the fetus. Although varicella is generally benign and self-limited in childhood, the physiological and immunological changes in pregnancy predispose individuals to more severe forms of the disease, with pneumonia representing the main maternal complication and a leading cause of morbidity and mortality. Vertical transmission may result in congenital varicella syndrome, the most severe fetal consequence, whose risk is greatest between the 13th and 20th weeks of gestation, or in severe neonatal varicella when maternal infection occurs in the peripartum period. This article presents a narrative review of the literature. To enhance methodological transparency and reproducibility, key principles of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) were applied to the literature search and study selection process. Searches were conducted in the PubMed/MEDLINE and SciELO databases, and 32 studies were included in the narrative synthesis. The review addresses the virology, pathophysiology, and epidemiology of VZV infection, including differences between temperate and tropical regions, as well as its clinical manifestations and maternal, fetal, and neonatal complications. Diagnosis is predominantly clinical, with the polymerase chain reaction being the most sensitive and specific confirmatory method and serology being useful mainly for the assessment of maternal immunity. Management encompasses the assessment of susceptibility, post-exposure prophylaxis according to current guideline recommendations, and early antiviral treatment of established infection. Preconception and postpartum vaccination remain the main preventive strategies. Despite recent advances, important gaps persist regarding prophylactic strategies and the long-term safety of antivirals during pregnancy. Full article

Background and Clinical Significance: Pregnancy-associated melanoma (PAM) is clinically challenging because the physiological pigmentary and naevus changes in pregnancy can obscure early malignancy, and the long-standing assumption that the hormonal milieu of pregnancy drives melanocytic transformation continues to shape clinical expectations. We present a case of postpartum-persistent melanoma in situ and use it to anchor a molecular reappraisal of that hormonal hypothesis. Case Presentation: We describe the clinical, dermoscopic, histopathological, and immunohistochemical findings in a 32-year-old woman with a peri-umbilical naevus that changed during the third trimester and persisted twelve months postpartum, and we review the hormonal, immunological, and diagnostic literature relevant to PAM. Dermoscopy showed a multicomponent pattern with asymmetry, irregular structureless areas, peripheral pseudopods, and central regression; excisional biopsy demonstrated an atypical intraepidermal melanocytic proliferation without dermal invasion (melanoma in situ, pTis cN0 cM0, Stage 0), with Melan-A positivity and reduced p16. The reviewed evidence indicates that melanomas lack classical oestrogen/progesterone receptors and that the dominant oestrogen and α-MSH signals act through non-classical, differentiating pathways (GPER, MC1R) that are growth-suppressive rather than oncogenic, while pregnancy provides an immunologically permissive and diagnostically obscuring context. Conclusions: Pregnancy is better understood not as a hormonal driver of melanoma but as a permissive and obscuring state in which the principal preventable harm is diagnostic delay; suspicious lesions in pregnant or postpartum women warrant the same urgency as in other patients, and structured dermoscopic surveillance of at-risk women is the rational response. Full article

Lameness is a major welfare and economic disorder in dairy production and a clinical sign with multiple causes. This review focuses on claw horn disruption lesions (CHDL), a major cause of periparturient lameness. Although hoof-centered prevention and treatment remain essential, preclinical systemic alterations, recurrence, and clustering with other transition-period disorders suggest that CHDL may sometimes represent the local expression of broader pathophysiology. We propose the Lameness Triad, in which three mechanisms converge: sustained endotoxemic pressure and TLR4-mediated innate immune activation, endothelial glycocalyx degradation and vascular dysfunction, and metabolic triage that reallocates resources from production toward defense. Their combined pathogenic pressure is proposed to produce clinical disease when it exceeds a cow-specific Susceptibility–Resilience Gate comprising mucosal barrier integrity, hepatic endotoxin clearance, immune calibration, redox reserve, hoof structural reserve, and prior damage. Ruminal dysbiosis, mammary involution, and postpartum uterine contamination may contribute to inflammatory and endotoxemic pressure, whereas the confined, continuously loaded digital corium may become a principal site of clinical expression. Longitudinal multi-omics studies identified inflammatory, urinary, and milk-metabolite alterations before diagnosis, with within-cohort serum and urine models discriminating cows that later became lame as early as eight weeks prepartum. These findings require prospective validation and do not establish the complete causal sequence. The framework extends, rather than replaces, established hoof-health programs and provides testable hypotheses for earlier detection, prevention, and selection for resilience. Full article

Background: During intrauterine life, the fetus is continuously exposed to rhythmic sensory stimuli; among these, the maternal heartbeat is one of the earliest and most biologically salient, contributing to the early organization of physiological regulation. This exploratory longitudinal observational study examined whether exposure to the maternal heartbeat influences neonatal autonomic activity and whether this response is moderated by prenatal maternal psychological distress. Methods: Sixteen dyads of mother–child were included in the analyses. Pregnant women were first assessed between 24 and 28 weeks of gestation: maternal distress was measured using the Depression Anxiety Stress Scales—21 (DASS-21), and maternal heartbeat recordings were obtained. At 3–4 weeks postpartum, neonates were exposed to recordings of their own mother’s heartbeat. Neonatal heart rate variability (HRV) was assessed using electrocardiography at rest and during the hearing of the maternal heartbeat. Results: Exposure to the heartbeat significantly reduced high-frequency (HF) HRV compared to baseline (p = 0.037), providing evidence for modulation of parasympathetic activity. Importantly, an interaction between condition and maternal distress was observed (p = 0.021), suggesting that neonatal autonomic responses differ as a function of maternal psychological state. Conclusions: Overall, these preliminary findings suggest that neonatal autonomic responses to maternal heartbeat exposure may not be uniform but may vary according to maternal psychological distress, highlighting the potential role of the maternal psychophysiological context in shaping early autonomic regulation. Full article

To delineate the serum proteomic profile of persistent subclinical hypocalcemia (pSCH) in periparturient dairy cows, elucidate its molecular pathogenesis, and provide a theoretical basis for early warning and precision prevention and control, we selected 12 Holstein dairy cows of similar age (2.92 ± 0.12 years), parity (1.56 ± 0.21), body condition score (BCS) (2.84 ± 0.04), milk yield (26.81 ± 0.22 kg/d), and day in milk (DIM) (6.60 ± 0.24 d) and no significant between-group differences as experimental animals. Based on serum calcium concentrations on postpartum days 1 to 4 and clinical presentation, the cows were divided into a healthy control group (serum calcium > 1.77 mmol/L on day 1 and >2.20 mmol/L on day 4 postpartum, n = 6) and a persistent subclinical hypocalcemia group (serum calcium ≤ 1.77 mmol/L on day 1 and ≤2.20 mmol/L on day 4 postpartum, n = 6). Serum samples were collected on postpartum days 1, 2, and 4 and analyzed using 4D-DIA quantitative proteomics. A total of 178 significantly differentially expressed proteins were identified (fold change > 1.2, p < 0.05), including 59 up-regulated and 119 down-regulated proteins. These differentially expressed proteins were mainly enriched in pathways involving endocrine and other factor-regulated calcium reabsorption, regulation of actin cytoskeleton, the tricarboxylic acid cycle (TCA cycle), and lipoic acid metabolism. The results indicate that the pathological state of pSCH is closely associated with abnormalities in calcium reabsorption regulation, actin cytoskeleton maintenance, and mitochondrial energy metabolism-related signaling pathways. The key proteins and pathways identified in this study provide a theoretical foundation for future in-depth research on the pathogenesis, prevention, and treatment of pSCH. Full article