Aust N Z J Obstet Gynaecol
· 2026 Apr · PMID 41879346
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BACKGROUND: Gestational diabetes mellitus (GDM) is a health concern with growing prevalence internationally. A limited number of studies have explored the differences in neonatal and obstetric outcomes between various GD...BACKGROUND: Gestational diabetes mellitus (GDM) is a health concern with growing prevalence internationally. A limited number of studies have explored the differences in neonatal and obstetric outcomes between various GDM treatment groups with conflicting results. AIMS: The aim of this study is to evaluate the differences in newborn birth parameters, obstetric and neonatal outcomes between mothers with diet-treated and insulin-treated GDM. MATERIAL AND METHODS: Neonatal outcomes and birth parameters from 4188 women and obstetric outcomes from 2356 women were divided into diet-only and insulin treated groups and analysed for differences. RESULTS: Most neonatal and obstetric outcomes were similar between the groups, except for large for gestational age (LGA) neonates (17% vs. 10%, p < 0.001), macrosomia (11% vs. 10%, p < 0.1), neonatal hypoglycaemia (18% vs. 14%, p < 0.01) and gestational age (39.0 vs. 38.6 weeks, p < 0.001), which were higher in the insulin group. Insulin-treated GDM is a positive predictor for birth head circumference (β = 0.3, p < 0.001), length (β = 0.5, p < 0.001), weight (β = 103.3, p < 0.001), LGA (OR 1.6 [95% CI 1.4-2.0], p < 0.001) and macrosomia (OR 1.4 [95% CI 1.1-1.8], p < 0.01) but a negative predictor for gestational age (β = -0.3, p < 0.001) and neonatal hypoglycaemia (OR 0.8 [95% CI 0.7-0.9], p < 0.01). CONCLUSIONS: Insulin-treated GDM was a positive predictor of birth parameters, LGA, and macrosomia. Further studies may compare the outcomes against various treatment selection criteria to evaluate the adequacy of current treatment guidelines.
McGannon C, Au LS, Neil P
… +2 more, Roberts C, Mol BWJ
Aust N Z J Obstet Gynaecol
· 2026 Apr · PMID 41879343
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BACKGROUND: Both twin pregnancy and short cervix are risk indicators for preterm birth. Cervical pessary and progesterone have been suggested to prevent preterm birth. A randomised trial was conducted in individuals carr...BACKGROUND: Both twin pregnancy and short cervix are risk indicators for preterm birth. Cervical pessary and progesterone have been suggested to prevent preterm birth. A randomised trial was conducted in individuals carrying twins with cervix below the 25th centile (less than 38 mm). METHODS: We conducted a single centre open-label randomised clinical trial at Monash Medical Centre in Victoria, Australia (Trial registration number: ACTRN12616000875404). Individuals with a twin pregnancy and mid-trimester (16 to 23 weeks) cervical length < 25th percentile were invited to participate. After informed consent, participants were randomly assigned to placement of cervical pessary or self-administered daily vaginal progesterone (200 mg), until 36 weeks of gestation or until onset of labour, whichever occurred first. Primary outcome was a composite adverse neonatal outcome, with preterm birth before 28 weeks as an important secondary outcome. RESULTS: Between 2 December 2019 and 27 July 2023, 159 individuals were screened, of whom 66 had a cervical length ≤ 38 mm, and 34 were randomised to Arabin pessary (N = 16) or progesterone (N = 18). One woman in the progesterone group withdrew consent after randomisation. The study was halted as studies elsewhere had indicated no benefit from pessary. Composite adverse neonatal outcome occurred in 41% (13/32) of the neonates in the Arabin pessary group compared with 29% (10/34) of the neonates in the progesterone group (risk ratio [RR] 1.38, 95% CI 0.71-2.69). Delivery before 28 weeks occurred in 19% (3/16) and 5.9% (1/17) (RR: 3.19, 95% CI 0.37-27.58). CONCLUSION: In individuals with a twin pregnancy and a short cervix, we could not report benefit from cervical pessary over progesterone.
Payne E, Heaney S, Collins C
… +2 more, Rollo M, Brown LJ
Aust N Z J Obstet Gynaecol
· 2026 Apr · PMID 41879340
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BACKGROUND: Management of diabetes in pregnancy requires input from multiple health professionals throughout the course of an individual's pregnancy. Implementing healthcare delivery that suits the local context of a met...BACKGROUND: Management of diabetes in pregnancy requires input from multiple health professionals throughout the course of an individual's pregnancy. Implementing healthcare delivery that suits the local context of a metropolitan or rural region may contribute to improvements in care delivery and pregnancy and birthing outcomes. AIMS: To compare healthcare delivery for people with diabetes in pregnancy in metropolitan and rural areas of Australia. MATERIALS AND METHODS: A cross-sectional survey was conducted, with questions focused on healthcare delivery for women with diabetes in pregnancy, including the multidisciplinary care provided. Data were collected via a nationwide survey of health professionals currently involved in the healthcare management of people with diabetes in pregnancy in Australia. Survey data were analysed using descriptive and inferential statistics. RESULTS: The main aspects of healthcare delivery were similar between metropolitan and rural respondents. The proportion of health professionals offering face-to-face services was greater in rural areas (n = 38, 100%) compared to metropolitan (n = 34, 71%). Rural respondents (21%) reported they were collocated with an endocrinologist and 48% with an obstetrician. This was compared to 71% of metropolitan respondents reporting being collocated with an endocrinologist, and 63% with an obstetrician. CONCLUSIONS: This research offers direction as to potential considerations when planning and implementing models of care in rural areas. Additional research confirming the priorities within the rural context is needed to support the development of optimal care delivery for pregnant people with diabetes living in rural regions.
Aust N Z J Obstet Gynaecol
· 2026 Apr · PMID 41879307
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Neonatal lupus, a condition primarily affecting infants born to mothers with anti-Ro/SSA and/or anti-La/SSB antibodies, is linked to congenital heart block (CHB), a potentially life-threatening complication. Hydroxychlor...Neonatal lupus, a condition primarily affecting infants born to mothers with anti-Ro/SSA and/or anti-La/SSB antibodies, is linked to congenital heart block (CHB), a potentially life-threatening complication. Hydroxychloroquine (HCQ), an antimalarial with immunomodulatory properties, has been shown to reduce CHB recurrence. This review examines current evidence on HCQ's role in preventing CHB in pregnancies affected by those autoantibodies, focusing on overall, primary and secondary prevention. Evidence supports HCQ in overall and secondary prevention, but data on its effectiveness for primary prevention is lacking. Clinical guidelines, antibody titre thresholds, foetal heart rate monitoring and the need for randomised controlled trials are discussed.
BACKGROUND: Ethnic minority patients experience a higher uterine fibroid disease burden and reduced access to minimally invasive myomectomy. Restrictive selection criteria may disproportionately exclude these patients fr...BACKGROUND: Ethnic minority patients experience a higher uterine fibroid disease burden and reduced access to minimally invasive myomectomy. Restrictive selection criteria may disproportionately exclude these patients from laparoscopic surgery. METHODS: This was a prospective service-evaluation database analysed retrospectively, including all conventional (non-robotic) laparoscopic myomectomies performed between January 2004 and December 2024 at a single UK university hospital. Primary outcomes were estimated blood loss (EBL), length of hospital stay (LOS) and operating time. Secondary outcomes were blood transfusion rate, conversion to laparotomy and analysis of fibroid burden by ethnicity. Outcomes were compared between patients with large fibroids (>10 cm), high-order fibroids (>10 fibroids removed), both and neither. We performed inferential descriptive statistics using SPSS v27 (SPSS Inc., Chicago, IL). RESULTS: Among 550 patients, 164 had large fibroids, 30 high-order fibroids, 18 both and 338 neither. Ethnic minority patients represented 77%, 93%, 89% and 72% of these groups, respectively. Mean EBL was higher in large fibroid (345 mL) and combined groups (483 mL) compared with neither (211 mL), without associated increases in transfusion, conversion to laparotomy, or LOS. Black African and Black Caribbean patients had greater fibroid burden and higher blood loss than Caucasian patients, reflecting disease severity rather than ethnicity as an independent determinant of outcome. CONCLUSIONS: In a specialist setting, laparoscopic myomectomy is feasible and safe for patients with large and/or multiple fibroids, including those from ethnic minority backgrounds with higher disease burden. Expansion of access within appropriately resourced centres may help reduce inequities in fibroid care.
BACKGROUND: Standardised early mobilisation within Enhanced Recovery After Surgery (ERAS) for endometrial cancer is lacking. This study developed and evaluated a protocol. METHODS: This retrospective study analysed outco...BACKGROUND: Standardised early mobilisation within Enhanced Recovery After Surgery (ERAS) for endometrial cancer is lacking. This study developed and evaluated a protocol. METHODS: This retrospective study analysed outcomes of a clinical quality improvement initiative conducted at a tertiary care centre (February 2021-May 2022). : Protocol developed via evidence/expert consensus. : Retrospective analysis of 90 patients who received care in two units during the study period. Patients admitted to unit A ( = 45) received a structured early mobilisation protocol implemented as part of routine clinical practice improvement, whilst patients admitted to unit B ( = 45) received standard care. Ward assignment was determined by bed availability at admission without researcher involvement in allocation. : Pulmonary function, physical capacity (ambulation time/day 5 walking distance) and gastrointestinal recovery. : Complications, LOS, emotional status (Brief Profile of Mood States, BPOMS). Statistical analyses included effect sizes and 95% confidence intervals. RESULTS: The intervention group was associated with significantly better first ambulation (6.8 ± 2.1 h vs. 18.5 ± 4.3 h, mean difference: 11.7 h, 95% CI: 10.3-13.1, < 0.001), day 5 walking distance (385 ± 68 m vs. 142 ± 45 m, mean difference: 243 m, 95% CI: 220-266, < 0.001), time to first flatus (28.5 ± 6.2 h vs. 48.3 ± 8.5 h, mean difference: 19.8 h, 95% CI: 16.9-22.7, < 0.001), fewer pulmonary complications (8.9% vs. 24.4%, OR: 0.30, 95% CI: 0.09-0.96, = 0.047), shorter LOS (4.2 ± 1.1 d vs. 6.8 ± 1.5 d, mean difference: 2.6 d, 95% CI: 2.0-3.2, < 0.001) and improved BPOMS anxiety/depression scores. CONCLUSIONS: This retrospective analysis suggests that the structured early mobilisation protocol, implemented as a clinical quality improvement initiative, was associated with improved recovery, reduced complications/LOS and better emotional wellbeing in endometrial cancer patients within ERAS.
BACKGROUND: Regular physical activity during pregnancy is associated with important maternal health benefits, yet the specific impact of walking on labour and neonatal outcomes remains unclear. Although walking is the mo...BACKGROUND: Regular physical activity during pregnancy is associated with important maternal health benefits, yet the specific impact of walking on labour and neonatal outcomes remains unclear. Although walking is the most common form of exercise among pregnant women, evidence linking walking levels to obstetric and neonatal results is still limited. We aim to explore the relationship between walking activity level in the third trimester of pregnancy (T3) and obstetric and neonatal outcomes. METHODS: This was a secondary analysis of the Walking_Preg Project (WPP) randomised clinical trial registered in the U.S. National Library of Medicine Trials registry (https://clinicaltrials.gov/study/NCT03735381). Participants were healthy, low-risk pregnant women who were not previously physically active. They were given pedometers and physical activity recommendations. The sample was classified at T3 as physically active (≥7,500 steps/day) or sedentary (<7,500 steps/day) according to Tudor-Locke and Bassett's index to classify pedometer-determined physical activity in healthy adults. Multivariate analyses were conducted to compare obstetric and neonatal outcomes between active and sedentary women. RESULTS: 41 pregnant women walked at least 7,500 steps per day in T3, while 137 did not reach that activity level. The crude and adjusted multivariate models showed an inverse relationship between walking ≥7,500 steps/day in T3 and unplanned caesarean delivery (adjusted OR 0.27, 95% CI 0.05-1.47) as well as a positive relationship with induction of labour (adjusted OR 1.10, 95% CI 0.46-2.61) and neonatal weight (adjusted B coef = 97.55, 95% CI -64.03-259.14; p = 0.23). However, statistical significance was not reached. CONCLUSIONS: In this secondary analysis, no statistically significant associations were observed between walking activity during the third trimester and obstetric or neonatal outcomes. Given the low adherence to the walking program and the exploratory nature of the analysis, these findings should be interpreted with caution and require confirmation in larger, adequately powered studies.
BACKGROUND: Inadequate childbirth readiness can adversely affect the birthing experience of pregnant women and may even influence their willingness to have further children. This study aimed to explore the determinants o...BACKGROUND: Inadequate childbirth readiness can adversely affect the birthing experience of pregnant women and may even influence their willingness to have further children. This study aimed to explore the determinants of childbirth readiness and the network relationships among these factors, thereby providing evidence to improve childbirth readiness. METHODS: This cross-sectional study surveyed 350 pregnant women attending Wuxi Maternity and Child Health Care Hospital. Latent profile analysis (LPA) was first performed using the four domains of the Childbirth Readiness Scale to identify subgroups of childbirth readiness, and potential associated factors were then screened using univariate analysis and multinomial logistic regression. A Bayesian network model was employed to construct the structural relationships of factors influencing childbirth readiness. RESULTS: Childbirth readiness was categorised into three levels: poor (26%), good (30.9%), and complete (43.1%). Univariate analysis revealed significant differences across the three categories in relation to age, parity, pregnancy complications, antenatal exercise, planned pregnancy, self-efficacy, eHealth literacy, fear of childbirth, and family support ( < 0.2). Multinomial logistic regression indicated that parity, self-efficacy, and eHealth literacy were important predictors of childbirth readiness. The Bayesian model identified self-efficacy, fear of childbirth, eHealth literacy, and parity as the nodes most closely associated with childbirth readiness, while planned pregnancy, antenatal exercise, family support, and age were linked indirectly through other nodes. CONCLUSIONS: Previous studies on childbirth readiness have mainly relied on regression models, which are unable to elucidate the intrinsic interconnections among influencing factors. By constructing a Bayesian model, this study demonstrated that women with high self-efficacy, no fear of childbirth, high eHealth literacy, and multiparity had the highest probability of achieving complete childbirth readiness (83.3%).
BACKGROUND: This study aimed to estimate the global trend of age-standardised incidence rates (ASIR) and age-standardised disability-adjusted life years (AS-DALYs) of pelvic organ prolapse from 1990 to 2021, and analyse...BACKGROUND: This study aimed to estimate the global trend of age-standardised incidence rates (ASIR) and age-standardised disability-adjusted life years (AS-DALYs) of pelvic organ prolapse from 1990 to 2021, and analyse the separate effects of age, period and birth cohort. METHODS: Data of pelvic organ prolapse's ASIR and AS-DALYs were obtained from the Global Burden of Disease (GBD) 2021. The regions were classified by the socio-demographic index (SDI). An age-period-cohort (APC) model was employed to analyse the effect of every age, period and birth cohort on pelvic organ prolapse's ASIR. RESULTS: In 2021, the global ASIR and AS-DALY were 317.51 (95% UI, 267.67-378.25) and 8.68 (95% UI, 4.26-16.38) per 100,000 population, respectively. The rates decreased globally and in five SDI regions from 1990 to 2021. APC analysis demonstrated that ASIR significantly increased with advancing age, exhibiting a bi-peak curve, with one peak appearing around 50 years and the other around 70 years. CONCLUSION: Over the past 32 years, the global ASIR and AS-DALY of pelvic organ prolapse have continued to decrease significantly, while in low SDI regions, the rates remain high. These findings highlight the need for targeted pelvic organ prolapse prevention programs and proper investment in pelvic floor care in low SDI regions.
Allin T, Taunton C, Ketchell F
… +1 more, Hempenstall A
Aust N Z J Obstet Gynaecol
· 2026 Feb · PMID 41640179
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Across Australia, cervical cancer incidence and mortality rates is highest in those living in rural and remote areas, First Nations people and those residing in areas of high socioeconomic disadvantage. One such area is...Across Australia, cervical cancer incidence and mortality rates is highest in those living in rural and remote areas, First Nations people and those residing in areas of high socioeconomic disadvantage. One such area is the Torres Strait, Queensland, with 81% of residents identifying as a First Nations person. To date, cervical cancer screening rates have not been examined in this area. This retrospective review aims to review the cervical cancer screening rates among people living in the Torres Strait over a 4-year and 7-month period from December 1, 2017, to June 30, 2022. Our findings revealed that, of those eligible for a cervical screening test, 2060/2920 (70.5%) had one or more cervical screening tests during the study period, resulting in an estimated five-year cervical screening coverage rate of 75.1%. No human papilloma virus was detected in 1935/2060 (93.9%) of tests. These findings we hope will refine local healthcare delivery to achieve the targets in the National Strategy, eliminating cervical cancer as a public health problem by 2035 in Australia.
BACKGROUND: Triage of human papillomavirus (HPV)-positive women with atypical squamous cells of undetermined significance (ASC-US) remains a longstanding clinical challenge in cervical cancer screening, as conventional s...BACKGROUND: Triage of human papillomavirus (HPV)-positive women with atypical squamous cells of undetermined significance (ASC-US) remains a longstanding clinical challenge in cervical cancer screening, as conventional strategies often lead to excessive colposcopy referrals. We conducted a diagnostic cohort study of 195 HPV-positive women who underwent ASC-US cytology. METHODS: Multigene DNA methylation analysis was performed on residual cervical exfoliated cells, using histology from colposcopy-directed biopsy and/or endocervical sampling as the reference standard to minimise colposcopy referrals. RESULTS: Our results showed that methylation levels of PAX1, EPB41L3, and FAM19A4 increased progressively from ≤ CIN1 to CIN2, CIN3, and cervical cancer, with significant decreases in ΔCt values from ≤ CIN1 to CIN3 for all three genes ( < 0.05). For detection of CIN2+, the assay achieved a sensitivity of 85.19%, specificity of 96.43%, positive predictive value (PPV) of 79.31%, negative predictive value (NPV) of 97.59%, and an area under the receiver operating characteristic curve (AUC) of 0.91, thereby avoiding colposcopy referrals in 96.43% (162/168). For CIN3+, the assay demonstrated sensitivity, specificity, PPV, NPV, and AUC values of 94.44%, 93.22%, 58.62%, 99.4%, and 0.94, respectively. Stratified analyses showed high and comparable sensitivity (81.82% vs. 87.50%), specificity (96.92% vs. 96.12%), and AUC (0.89 vs. 0.92) in women with HPV16/18 compared with those with non-16/18 high-risk HPV. Optimal diagnostic accuracy was observed in women aged ≥30 years, with sensitivities ranging from 85.70% to 100%, specificities from 94.44% to 100%, and AUC values ranging from 0.93 to 0.97. In contrast, the performance was suboptimal in women aged <30 years (sensitivity, 33.33%; AUC, 0.64). CONCLUSIONS: The host multigene DNA methylation assay demonstrates high specificity and good sensitivity for triaging HPV-positive ASC-US women, with the potential to reduce colposcopy referrals while maintaining robust detection of high-grade lesions, particularly in those aged ≥30 years.
BACKGROUND: Postoperative voiding dysfunction is common after nerve-sparing radical hysterectomy (NSRH); therefore, we examined whether adjunct transcutaneous electrical nerve stimulation (TENS) could improve bladder man...BACKGROUND: Postoperative voiding dysfunction is common after nerve-sparing radical hysterectomy (NSRH); therefore, we examined whether adjunct transcutaneous electrical nerve stimulation (TENS) could improve bladder management, pelvic floor muscle strength, and quality of life (QoL) in this population. METHODS: A total of 78 NSRH patients from May 2023 to May 2024 were divided into conventional catheter management (control group, = 39) and conventional management + TENS (intervention group, = 39). Outcomes including urinary retention incidence, postvoid residual urine volume (PVR), catheter indwelling duration, intervention compliance, pelvic floor muscle strength grading, voiding function parameters, QoL scores, and safety were assessed. RESULTS: The intervention group demonstrated significantly lower urinary retention incidence, reduced PVR, and shorter catheter duration versus controls (all < 0.05). Both groups maintained > 90% intervention compliance ( > 0.05). Post-intervention voiding parameters (FD, BC, MCC) improved more significantly in the intervention group (all < 0.05), with superior pelvic floor muscle strength grading ( < 0.001). QoL assessment revealed lower functional domain scores and higher symptom/global health scores in the intervention group (all < 0.001). Safety analysis showed only mild dermal reactions in the intervention group, without significant between-group difference in complication rates ( > 0.05). CONCLUSIONS: TENS would significantly improves bladder function, pelvic floor muscle strength, and QoL in post-NSRH patients with a favourable safety profile, demonstrating substantial clinical value.
BACKGROUND: Gushen Antai recipe (GSAT), known herbal medicine, has long been used in China to treat early pregnancy loss. Several randomised controlled trials have demonstrated its efficacy in improving clinical pregnanc...BACKGROUND: Gushen Antai recipe (GSAT), known herbal medicine, has long been used in China to treat early pregnancy loss. Several randomised controlled trials have demonstrated its efficacy in improving clinical pregnancy rates. This study aimed to elucidate the mechanism of GSAT in patients undergoing in vitro fertilisation-embryo transfer (IVF-ET). METHODS: Patients undergoing IVF-ET were recruited on day 14 after embryo transfer. Participants either received GSAT alongside hormonal medication for 2 weeks (intervention group) or received hormonal treatment (control group). Plasma metabolites and inflammatory factors was analysed by gas chromatography-mass spectrometry and enzyme-linked immunosorbent assay, respectively. Faecal microbiota was assessed by 16S rRNA sequencing. RESULTS: GSAT was found to contain 56.44% flavonoids, primarily come from Scutellariae Radix, including baicalin, baicalein, wogonoside, wogonin, oroxylin A and Chrysin 6-C-glucoside 8-C-arabinoside. At the end of the fourth week after embryo transfer, plasma levels of interleukin (IL)-2 and tumour necrosis factor-α were significantly lower in the intervention group than in the control group, whereas the anti-inflammatory cytokine IL-10 were markedly higher (687.3 vs. 448.5 pg/mL, < 0.01). Moreover, the plasma IL-10 levels and proportion of four kinds of fatty acids (lauric acid, myristic acid, palmitic acid, linoleic acid) in plasma correlated with each other. These fatty acids were not directly detected in GSAT and may originate from biosynthesis by gut microbiota. CONCLUSIONS: The alteration of plasma cytokine levels (IL-10, TNF-α and IL-2) associated with GSAT intervention was linked to specific fatty acids produced by characteristic intestinal microbiota. These results provide insights into the mechanism underlying the role of the GSAT in improving clinical pregnancy rates.
BACKGROUND: Diastasis recti abdominis (DRA) is characterised by a separation of the rectus abdominis muscles, which is common in the postpartum period. This randomised controlled trial investigated the effects of a physi...BACKGROUND: Diastasis recti abdominis (DRA) is characterised by a separation of the rectus abdominis muscles, which is common in the postpartum period. This randomised controlled trial investigated the effects of a physiotherapy protocol combining abdominal exercises and physical agents-namely electromagnetic shock waves, transfer of energy capacitive and resistive (TECAR) therapy, and neuromuscular electrical stimulation-on reducing the inter-rectus distance in women with DRA six months after childbirth. METHODS: Sixty women diagnosed with DRA were randomised into three groups: kinesiotherapy (Group A); electromagnetic shock waves, TECAR therapy, and neuromuscular electrostimulation (Group B); and a combination of both (Group C). The inter-rectus distance (IRD) of participants was assessed before and after treatment, with re-evaluation conducted sixty days after the initial assessment, using ultrasound and abdominal perimeter measurements. RESULTS: group C showed a 0.80 cm reduction in supraumbilical IRD when compared with Group B. In the infraumbilical region, Group C had a 0.74 cm reduction compared to Group A and 0.85 cm compared to Group B. Regarding abdominal perimeter, Groups B and C showed greater reductions in the infraumbilical circumference than Group A, with mean differences of approximately 10 cm. No significant differences were observed in the supraumbilical and umbilical regions. CONCLUSIONS: the combination of kinesiotherapy and physical agents is more effective in reducing inter-rectus distance and abdominal circumference than either approach alone in postpartum women with diastasis recti abdominis.
BACKGROUND: Pelvic inflammatory disease (PID) is a common gynaecologic condition linked to infertility, ectopic pregnancy, and reproductive tract cancers. While active smoking has been associated with PID, the impact of...BACKGROUND: Pelvic inflammatory disease (PID) is a common gynaecologic condition linked to infertility, ectopic pregnancy, and reproductive tract cancers. While active smoking has been associated with PID, the impact of environmental tobacco smoke (ETS) on non-smoking women remains unclear. Most studies rely on self-reported exposure, which may be inaccurate. Cotinine, a stable nicotine metabolite, serves as an objective biomarker of tobacco exposure. This study investigated the association between serum cotinine levels and PID risk in non-smoking women using data from the National Health and Nutrition Examination Survey (NHANES). METHODS: This cross-sectional study included 3,718 non-smoking women aged ≥18 years from NHANES 2013-2020. ETS exposure was assessed using serum cotinine measured by isotope dilution high-performance liquid chromatography with tandem mass spectrometry. Cotinine levels were categorised as unexposed, low, or high exposure. PID was identified based on self-reported treatment for pelvic infections. Weighted logistic regression was used to examine associations between cotinine and PID, adjusting for confounders identified by a directed acyclic graph. Restricted cubic spline and subgroup analyses were also conducted. RESULTS: Among participants, 3.1% reported a history of PID. Those with PID had higher serum cotinine levels. In fully adjusted models, each one-unit increase in log-transformed cotinine was associated with a 10% increase in PID risk (OR = 1.10; 95% CI: 1.02-1.19). High ETS exposure (≥3 ng/mL) was linked to a significantly higher risk of PID compared to unexposed individuals (OR = 2.53; 95% CI: 1.05-6.08). A linear dose-response relationship was observed. Subgroup analyses showed consistent results across all strata. CONCLUSION: Serum cotinine-defined ETS exposure was significantly associated with increased PID risk in non-smoking women. Reducing ETS exposure may help prevent reproductive tract infections.