Urinary tract infections and risk of preterm birth: a systematic review and meta-analysis.

This systematic review and meta-analysis assessed the association between urinary tract infections (UTIs) during pregnancy and the risk of preterm birth (PTB). We searched multiple databases for relevant observational studies, categorizing them as UTI-based (comparing PTB incidence in women with and without UTIs) or PTB-based (comparing UTI prevalence in women with and without PTB). Using a random-effects model in Stata software version 17.0, we estimated pooled and adjusted odds ratios (ORs) with 95% confidence intervals (CIs), and performed subgroup, sensitivity, and cumulative analyses to explore heterogeneity. In total, 30 studies comprising 32 datasets were included, involving a total of 249,810 cases and 2,626,985 healthy controls. The meta-analysis revealed a significant positive association between UTIs during pregnancy and PTB occurrence (OR, 1.92; 95% CI, 1.62-2.27). A sub-group analysis based on studies, the participants showed significant association in both PTB-based (OR, 2.01; 95% CI, 1.58-2.56) and UTI-based studies (OR, 1.79; 95% CI, 1.42-2.26). However, Egger's test indicated the presence of publication bias (p=0.020), and substantial heterogeneity was observed across the included studies (I2=96.6; p< 0.001). These findings emphasize the critical importance of early detection and effective management of UTIs in pregnant women to reduce the risk of PTB and its associated adverse outcomes. While the results highlight a robust link between UTIs during pregnancy and PTB risk, the potential influence of publication bias and substantial heterogeneity should be considered to interpret these findings. Further research is needed to better understand the underlying mechanisms and to develop targeted interventions for high-risk pregnant women.

Prevention of preterm birth in twin-to-twin transfusion syndrome: a systematic review and network meta-analysis.

OBJECTIVES: We aimed to perform a systematic review and network meta-analysis to evaluate the preventive strategies for preterm birth in twin-to-twin transfusion syndrome. METHODS: PubMed, Embase and Cochrane Central were searched from inception to December 2023 with no filters. Additionally, the reference lists of the included studies were manually examined to identify any supplementary studies. We selected randomized controlled trials and cohorts comparing interventions to prevent preterm birth in twin pregnancies complicated by twin-to-twin transfusion syndrome. A random-effects frequentist network meta-analysis was performed using RStudio version 4.3.1. Randomized controlled trials and cohorts were assessed respectively using the Risk of Bias in Non-randomized Studies of interventions tool and Cochrane Collaboration's tool for assessing risk of bias in randomized trials. RESULTS: In this systematic review and meta-analysis, we included eight studies comprising a total of 719 patients. Compared with expectant management, cerclage stood out as the only intervention associated with an increase in the survival of at least one twin (risk ratio 1.12; 95 % confidence interval 1.01-1.23). Our subgroup analysis based on different thresholds for short cervix demonstrated a significant reduction in the risk of preterm birth before 32 weeks with ultrasound-indicated cerclage using a 15 mm criterion (risk ratio 0.65; 95 % confidence interval 0.47-0.92). CONCLUSIONS: Our study suggests the potential benefit of cerclage as a preventive strategy for preterm birth in pregnancies complicated by twin-to-twin transfusion syndrome. These findings highlight the necessity for further investigation to corroborate our results and address the optimal threshold for ultrasound-indicated cerclage.

Assessment of obstetric history and cervical length as risk factors for preterm birth / Evaluación de la história obstétrica y la longitud cervical como factores de riesgo para el parto prematuro

Introduction: Preterm birth, before 37 weeks of gestation, is the main determinant of neonatal morbidity and mortality and is associated with serious consequences,including compromised quality of life for the affected individual and physical, psychological, and economic costs. Objective: To evaluate the correlation of obstetric history, cervicovaginal infections, and cervical length with preterm birth. A prospective, blind cohort study evaluated 1,370 pregnant women from Ribeirão Preto between 20 and 25 weeks of gestation. Materials and methods: The correlation between obstetric history, cervical length, and gestational age at birth was obtained by calculating the relative risk of the different variables. Results: The distribution of pregnant women according to cervical length (CL) showed a predominance of women with a cervix longer than 2.5 cm (n = 1,308, 95.8%), followed by women with a cervix between 2 and 2.49 cm (n = 42, 3.1%) and < 2 cm (n = 15, 1.1%). Among the 1,370 pregnant women evaluated, 133 had spontaneous preterm birth (< 259 days); 14 (10.5%) preterm births occurred in women under 19 years of age, 105 (79%) in women between 19 and 35 years, and 14 (10.5%) in women older than 35 years. Microbiological analysis showed the growth of Mycoplasma hominis, Ureaplasma urealyticum, and other bacteria in 8, 17, and 16 women with preterm birth, respectively. Among the 133 women with spontaneous preterm birth, CL was < 2.5 cm in 15 women, < 2 cm in 3, < 1.5 cm in 3, and < 1 cm in 2. Conclusion: The identification of pregnant women at high risk for preterm delivery can reduce the incidence of preterm birth. Although no gold standard test exists for the prediction of preterm birth, this study confirms that the measurement of CL is a good individual predictor.

Introducción: El nacimiento pretérmino, antes de las 37 semanas de gestación, es el principal determinante de la morbimortalidad neonatal y se asocia a graves consecuencias,incluyendo el compromiso de la calidad de vida del individuo afectado y costes físicos, psicológicos y económicos. Objetivo: Evaluar la correlación de los antecedentes obstétricos, infecciones cervicovaginales y longitud cervical con el parto prematuro. Estudio de cohorte prospectivo, ciego, evaluando 1.370 gestantes de Ribeirão Preto entre 20 y 25 semanas de gestación. Material y métodos: La correlación entre los antecedentes obstétricos, la longitud cervical y la edad gestacional al nacer se obtuvo calculando el riesgo relativo de las diferentes variables. Resultados: La distribución de las gestantes según la longitud cervical (LC) mostró un predominio de mujeres con cuello uterino mayor de 2,5 cm (n = 1,308, 95.8%), seguidas de mujeres con cuello uterino entre 2 y 2,49 cm (n = 42, 3.1%) y menor de 2 cm (n = 15, 1.1%). De las 1,370 embarazadas evaluadas, 133 tuvieron un parto prematuro espontáneo (< 259 días); 14 (10.5%) partos prematuros se produjeron en mujeres menores de 19 años, 105 (79%) en mujeres de entre 19 y 35 años, y 14 (10.5%) en mujeres mayores de 35 años. Los análisis microbiológicos mostraron la proliferación de Mycoplasma hominis, Ureaplasma urealyticum y otras bacterias en 8, 17 y 16 mujeres con parto prematuro, respectivamente. Entre las 133 mujeres con parto prematuro espontáneo, la CL fue < 2.5 cm en 15 mujeres, < 2 cm en 3, < 1.5 cm en 3 y < 1 cm en 2. Conclusión: La identificación de las gestantes con alto riesgo de parto prematuro puede reducir la incidencia de parto prematuro. Aunque no existe una prueba de referencia para la predicción del parto prematuro, este estudio confirma que la medición de la longitud cervical es una buena predicción individual.

Hypertensive disorders during pregnancy as a major cause of preterm birth and adverse perinatal outcomes: findings from a Brazilian National Survey.

OBJECTIVE: This study aimed to evaluate the prevalence of hypertensive disorders during pregnancy among Brazilian women with preterm births and to compare the epidemiological characteristics and perinatal outcomes among preterm births of women with and without hypertension. METHODS: This was a secondary cross-sectional analysis of the Brazilian Multicenter Study on Preterm Birth. During the study period, all women with preterm births were included and further split into two groups according to the occurrence of any hypertensive disorder during pregnancy. Prevalence ratios were calculated for each variable. Maternal characteristics, prenatal care, and gestational and perinatal outcomes were compared between the two groups using χ2 and t-tests. RESULTS: A total of 4,150 women with preterm births were included, and 1,169 (28.2%) were identified as having hypertensive disorders. Advanced maternal age (prevalence ratio (PR) 2.49) and obesity (PR= 2.64) were more common in the hypertensive group. The gestational outcomes were worse in women with hypertension. Early preterm births were also more frequent in women with hypertension. CONCLUSION: Hypertensive disorders of pregnancy were frequent among women with preterm births, and provider-initiated preterm births were the leading causes of premature births in this group. The factors significantly associated with hypertensive disorders among women with preterm births were obesity, excessive weight gain, and higher maternal age.

Pregnancy after kidney transplantation: 40 years single-center experience.

BACKGROUND: Kidney transplantation (KT) improves quality of life, including fertility recovery. OBJECTIVE: to describe outcomes of post-KT pregnancy and long-term patient and graft survival compared to a matched control group of female KT recipients who did not conceive. METHODS: retrospective single-center case-control study with female KT recipients from 1977 to 2016, followed-up until 2019. RESULTS: there were 1,253 female KT patients of childbearing age in the study period: 78 (6.2%) pregnant women (cases), with a total of 97 gestations. The median time from KT to conception was 53.0 (21.5 - 91.0) months. Abortion rate was 41% (spontaneous 21.6%, therapeutic 19.6%), preterm delivery, 32%, and at term delivery, 24%. Pre-eclampsia (PE) occurred in 42% of pregnancies that reached at least 20 weeks. The presence of 2 or more risk factors for poor pregnancy outcomes was significantly associated with abortions [OR 3.33 (95%CI 1.43 - 7.75), p = 0.007] and with kidney graft loss in 2 years. The matched control group of 78 female KT patients was comparable on baseline creatinine [1.2 (1.0 - 1.5) mg/dL in both groups, p = 0.95] and urine protein-to-creatinine ratio (UPCR) [0.27 (0.15 - 0.44) vs. 0.24 (0.02 - 0.30), p = 0.06]. Graft survival was higher in cases than in controls in 5 years (85.6% vs 71.5%, p = 0.012) and 10 years (71.9% vs 55.0%, p = 0.012) of follow-up. CONCLUSION: pregnancy can be successful after KT, but there are high rates of abortions and preterm deliveries. Pre-conception counseling is necessary, and should include ethical aspects.

[Comment on article "Risk factors associated with preterm birth in a second level hospital"]. / Comentario al artículo "Factores de riesgo asociados a parto pretérmino en un hospital de segundo nivel".

Preterm birth is a worldwide problem with a high economic impact and morbimortality in children. Therefore, the literature has focused on finding modifiable factors associated with this entity, such as the study "Risk factors associated with preterm birth in a second level hospital," which concluded that "100% of risk factors associated with preterm birth are potentially preventable". Our team reanalyzed the results and found in the regression model that premature rupture of membranes was the only variable associated with preterm birth. This variable is not 100% preventable, so the results found are different from the authors' conclusions.

El parto pretérmino es un problema a nivel mundial que tiene un alto impacto económico y de morbimortalidad en los niños. Por lo tanto, la literatura se ha centrado en encontrar factores modificables asociados a esta entidad, como el estudio de "Factores de riesgo asociados a parto pretérmino en un hospital de segundo nivel de atención", el cual tiene como conclusión que "El 100% de los factores asociados a parto pretérmino son potencialmente prevenibles". Nuestro equipo volvió a analizar los resultados y encontró en el modelo de regresión que la ruptura prematura de membranas fue la única variable asociada a parto pretérmino. Esta variable no es 100% prevenible, por lo que los resultados encontrados son diferentes a las conclusiones de los autores.

Temporal trends and factors associated with preterm birth in Chile, 1992-2018. / Tendencia temporal y factores asociados al parto prematuro en Chile, 1992-2018.

An analytical study based on Chilean birth records obtained from the Department of Statistics and Health Information (DEIS) was conducted. This study aimed to evaluate temporal trends in preterm births by maternal age in Chile from 1990 to 2018. Results show that the preterm birth rate in 1992 was 5.0% and increased to 7.2% in 2018. The average annual percent change (AAPC) was 1.44. Age groups at the extremes (19 and under and 35 and over) presented the highest rates of preterm birth, both at the beginning and at the end of the study period. The latter group showed a smaller decrease at the beginning (1992 to 1995), with an annual percentage change (APC) of -3.00. The probability of preterm birth in both groups was higher compared to the 20-34 year old group. Although Chile boasts some of the best maternal and child health indicators in the region, repercussions associated with the current postponement of maternity - including preterm birth - must be monitored.

Se realizó un estudio analítico con base en los registros poblacionales de nacimientos en Chile, obtenidos del Departamento de Estadística e Información en Salud (DEIS), con el objetivo de evaluar la tendencia temporal de los partos prematuros en Chile en el periodo 1990-2018, asociado a la edad de la madre. Los resultados muestran que, para el año 1992, la tasa de parto prematuro fue del 5,0%, aumentando a 7,2% en 2018. El promedio del porcentaje del cambio anual (PPCA) fue de 1,44. Los grupos etarios extremos ­menor o igual de 19 años y 35 y más años­ fueron los que presentaron las tasas de parto prematuro más altas, tanto al inicio y como al término del periodo, siendo este último grupo el que mostró una menor disminución al inicio del periodo (1992-1995), con porcentaje de cambio anual (PCA) de ­3,00. Para ambos grupos, la probabilidad de un parto prematuro fue mayor respecto del grupo de 20 a 34 años. Chile, presenta uno de los mejores indicadores de salud materna e infantil para la región; no obstante, dada la actual postergación de la maternidad, deben vigilarse las repercusiones asociadas, dentro de ellas un nacimiento prematuro.

Serum cytokines in second trimester pregnancy and their relationship with spontaneous preterm births in the Ribeirão Preto and São Luiz cohorts.

OBJECTIVE: To evaluate the association between second trimester plasma cytokine levels in asymptomatic pregnant women and preterm births (PTB) in an attempt to identify a possible predictor of preterm birth. METHODS: The study design was a nested case-control study including women with singleton a gestational age between 20-25(+ 6) weeks from two Brazilian cities. The patients were interviewed, Venous blood samples were collected. The participants were again evaluated at birth. A total of 197 women with PTB comprised the case group. The control group was selected among term births (426 patients). Forty-one cytokines were compared between groups. RESULTS: When only spontaneous PTB were analyzed, GRO, sCD40L and MCP-1 levels were lower in the case group (p < 0.05). Logarithmic transformation was performed for cytokines with discrepant results, which showed increased levels of IL-2 in the group of spontaneous PTB (p < 0.05). In both analyses, the incidence of maternal smoking and of a history of preterm delivery differed significantly between the case and control groups. In multivariate analysis, only serum GRO levels differed between the case and control groups. CONCLUSION: Lower second trimester serum levels of GRO in asymptomatic women are associated with a larger number of PTB. This finding may reflect a deficient maternal inflammatory response.

[Epidemiological characterization of COVID-2019 in Mexican pregnant women: a cohort study]. / Caracterización epidemiológica de la COVID-2019 en población obstétrica mexicana: estudio de cohorte.

Background: COVID-19 in pregnancy can increase the risk of complications due to the cardiorespiratory and immunological changes typical of pregnancy. Objective: To report the epidemiological characterization of COVID-19 in Mexican pregnant women. Material and methods: Cohort study on pregnant women with a positive COVID-19 test, which were followed until delivery and one month later. Results: 758 pregnant women were included in the analysis. Mothers' mean age was 28.8 ± 6.1 years; the majority were workers 497 (65.6%) and with an urban origin (482, 63.6%); the most common blood group was O with 458 (63.0%); 478 (63.0%) were nulliparous women and more than 25% had some comorbidities; the average gestation weeks at infection were 34.4 ± 5.1 weeks; only 170 pregnant women (22.4%) received vaccination; the most frequent vaccine was BioNTech Pfizer (96, 60%); there were no serious adverse events attributed to vaccination. The mean gestational age at delivery was 35.4 ± 5.2 weeks; 85% of pregnancies were cesarean section; the most frequent complication was prematurity (406, 53.5%), followed by preeclampsia (199, 26.2%); there were 5 cases of maternal death and 39 cases of perinatal death. Conclusions: COVID-19 in pregnancy increases the risk of preterm birth, preeclampsia, and maternal death. Vaccination against COVID-19 in this series showed no risk for pregnant women and their newborns.

Introducción: la COVID-19 en el embarazo puede incrementar el riesgo de complicaciones debido a los cambios cardiorrespiratorios e inmunológicos propios de la gestación. Objetivo: reportar la caracterización epidemiológica de la COVID-19 en población obstétrica mexicana. Material y métodos: estudio de cohorte en embarazadas con prueba positiva para COVID-19 que fueron seguidas hasta la resolución del embarazo y un mes después. Resultados: 758 mujeres embarazadas fueron incluidas en el análisis. La media de edad en las madres fue 28.8 ± 6.1 años; la mayoría trabajadoras 497 (65.6%) y de origen urbano (482, 63.6%); el grupo sanguíneo más común fue O 458 (63.0%); 478 (63.0%) fueron primigestas, y más del 25% padecía comorbilidades; las semanas de gestación promedio al contagio fueron 34.4 ± 5.1 semanas; solo 170 gestantes (22.4%) recibieron vacunación; la vacuna más frecuente fue BioNTech Pfizer (96, 60%); no hubo eventos adversos graves atribuibles a la vacunación. La edad gestacional media al nacer fue de 35.4 ± 5.2 semanas; el 85% de los embarazos se interrumpieron por cesárea; la complicación más frecuente fue la prematurez con 406 (53.5%), seguida de preeclampsia con 199 (26.2%); hubo 5 casos de muerte materna y 39 casos de muerte perinatal. Conclusiones: la COVID-19 en el embarazo aumenta el riesgo de parto prematuro, preeclampsia y muerte materna. Al menos en esta serie la vacunación contra COVID-19 no mostró riesgo para las mujeres embarazadas y sus recién nacidos.

COVID-19 mitigation measures increase preterm birth and low birth weight in the public healthcare system in Uruguay.

OBJECTIVE: To evaluate the impact of the COVID-19 pandemic on preterm birth (PB) and low birth weight (LBW), comparing public and private healthcare systems of the National Integrated Health System in Uruguay, where the mitigation measures for the COVID-19 pandemic generated an immediate socioeconomic and psychological crisis, which caused a sharp widening of existing socioeconomic inequalities. METHODS: A national observational study was conducted comparing perinatal outcomes in the first 6 months of 2020 (period of the pandemic without pregnancy infections), which was the beginning of the pandemic, with the same period of the previous year 2019 (pre-pandemic period with no mitigation measures) among pregnant women from the public and private health systems. Data were retrieved from the national database (Informatic Perinatal System) and analyzed by healthcare system category. RESULTS: A total of 36 559 deliveries were assessed: 18 563 in the 2019 study period and 17 996 in the 2020 study period. In the public system, there was a significant increase in the risk of LBW (adjusted relative risk [aRR] 1.12, 95% confidence interval [CI] 1.05-1.36) and of the composite outcome (PB or LBW) (aRR 1.15, 95% CI 1.04-1.26). In the private system, by contrast, there was a non-statistically significant decrease of LBW and there were no changes in the incidence of PB and the composite outcome in 2020. CONCLUSION: The different evolution of birth outcomes in the public and private systems suggests an unequal impact of mitigation measures on populations of different socioeconomic levels. Given that no COVID-19 infections were identified in pregnant women during the study period, this research offers an opportunity to differentiate the biologic effects of the virus from the psychological and social impacts derived from containment measures. GOV IDENTIFIER: NCT05087160.

In vitro fertilization as an independent risk factor for perinatal complications: Single-center 10 years cohort study.

OBJECTIVES: Assisted Reproductive Technology (ART) has made great strides in the past forty-years, but no medical treatment comes without side effects. Despite several studies reporting high incidences of perinatal complications, the association is inconclusive. Also, the effect of racially and ethnically distinguished Asian population undergoing ART on perinatal outcomes is not well studied. Therefore, this study attempts to compare various perinatal outcome parameters in ART, and spontaneously conceived singleton pregnancies from a single high-volume tertiary care center. METHODS: This is a retrospective cohort study from a single tertiary infertility center, carried out from January 2011 to September 2020. The study included 1,125 IVF conceived babies (AB group) and 7,193 spontaneous conceived babies (SB group). The groups were compared using the Pearson Chi-square test and adjusted odds ratio, calculated using the multivariate analysis. RESULTS: Most of the perinatal complications, such as preterm birth (PTB), early preterm birth, low birth weight (LBW), extremely low birth weight, small for gestational age, large for gestational age babies, neonatal intensive care unit (NICU) admission, need for surfactant, meconium aspiration syndrome, neonatal seizures, intraventricular hemorrhage, hypoxic-ischemic encephalopathy, and patent ductus arteriosus was significantly increased in the AB group when compared to the SB group (p<0.05). In-vitro fertilization (IVF) independently increases the risk of LBW (aOR 2.530; 95% CI 2.194-2.917), PTB (aOR 4.004; 95% CI 3.496-4.587), NICU admission (aOR 2.003; 95% CI 1.610-2.492) and neonatal seizures (aOR 9.805; 95% CI 5.755-16.706).Conclusions: All ART-conceived pregnant patients should receive antenatal counselling regarding perinatal complications and should deliver at a tertiary care center with appropriate NICU support.

A meta-analysis of the effect of Sjögren's syndrome on adverse pregnancy outcomes.

OBJECTIVE: This study aimed to assess the correlation between Sjögren's Syndrome (SS) and adverse pregnancy outcomes, with the aim of providing a basis for preconception and pregnancy interventions in women with SS. METHODS: A search of electronic databases in English and Chinese databases from January 2005 to December 2021, was conducted to collect the literature of case-control studies or cohort studies on the association between SS and pregnancy outcome studies. Literature inclusion and data extraction were performed according to established criteria, and the Newcastle-Ottawa scale was used to evaluate the quality of the literature. Stata 15 software was used for meta-analysis. RESULTS: A total of nine papers were included in this study. Meta-analysis results showed that SS was associated with spontaneous abortion (RR = 8.85, 95% CI 3.10‒25.26), preterm birth (RR = 2.27, 95% CI 1.46‒3.52), low birth mass (RR = 1.99, 95% CI 1.34‒2.97), and birth defects (RR = 4.28, 95% CI 3.08‒5.96). CONCLUSION: SS can increase the incidence of adverse pregnancy outcomes.

Association between preterm births and socioeconomic development: analysis of national data.

BACKGROUND: The increasing prevalence of preterm birth, which is a global phenomenon, is attributable to the increased medical indications, artificial gestations, and some socioeconomic factors. This study was conducted to identify whether development and equality indices are associated with the incidence of preterm birth, specifically, spontaneous and elective preterm births. METHODS: This retrospective observational study comprised an analysis of data on live births from 2019 in Brazil and on socioeconomic indices that were derived from census information in 2017. Data were summarised using absolute and relative frequencies. Spearman's correlation was used to determine the correlation between socioeconomic factors and the preterm birth rate. Multiple beta regression analysis was performed to determine the best model of socioeconomic covariates and preterm birth rate. The significance level was set at 5%. RESULTS: In 2019 in Brazil, the preterm birth rate was 11.03%, of which 58% and 42% were spontaneous and elective deliveries, respectively. For all preterm births, Spearman's correlation varied from ρ = 0.4 for the Gini Index and ρ = - 0.24 for illiteracy. The best fit modelled the spontaneous preterm birth fraction as a negative function of the Human Development Index (HDI). The best-fit model considered the expected elective preterm birth fraction as a positive function of the HDI and as a negative function of the Gini Index, which was used as a precision parameter. CONCLUSIONS: We observed a reduction in the fraction of spontaneous preterm births; however, the distribution was not uniform in the territory: higher rates of spontaneous preterm birth were noticed in the north, northeast, and mid-west regions. Thus, areas with lower education levels and inequal income distribution have a higher proportion of spontaneous preterm birth. The fraction of elective preterm birth was positively associated with more advantaged indices of socioeconomic status.

Influence of overweight and obesity on perinatal outcomes in assisted reproduction: a retrospective cohort study.

BACKGROUND: In spontaneous pregnancies, maternal weight and gestational diabetes are independent risk factors for macrosomia and large-for-gestational-age newborns. Furthermore, maternal body mass index (BMI) of ≥25 kg/m2 is associated with worse neonatal vitality, classified as an Apgar score of < 7 at the fifth minute of life. However, few studies have evaluated the influence of BMI on perinatal outcomes in pregnancies resulting from assisted reproduction. Therefore, this study aimed to analyze whether the perinatal outcomes of assisted reproduction are influenced by BMI. METHODS: This was a retrospective cohort study performed at a reproductive medicine center. Patients undergoing assisted reproduction (2013-2020) were divided into three groups according to their BMI (kg/m2): group 1, < 25; group 2, 25-29.9, and group 3, ≥30. In total, 1753 in vitro fertilization embryo transfer cycles were analyzed. Data were expressed as mean ± standard deviation or frequency (%). The analysis of variance and chi-square test were performed for comparison. To determine the participants and number of cycles for these analyses, generalized estimating equations were used, considering p < 0.05. RESULTS: In groups 1, 2, and 3, the rates of live birth were 33.5, 32.3, and 29.9% (p = 0.668); preeclampsia were 2.9, 6.1, and 6.3% (p = 0.268); small-for-gestational-age newborns were 23, 23.2, and 21.7% (p = 0.965); macrosomia were 1.9, 0.9, and 2.7% (p = 0.708); Apgar score > 7 at the fifth minute were 97.6, 98.2, and 100% (p = 0.616); and preterm birth were 29.6, 30.1, and 35.1% (p = 0.970), respectively. CONCLUSIONS: In conclusion, although the three groups had similar perinatal outcomes in this study, the study population was too small for conclusive results. The higher the BMI, the lower the chances of clinically relevant LBR and the higher the chances of premature labor and preeclampsia.

Unsupervised Learning Applied to the Stratification of Preterm Birth Risk in Brazil with Socioeconomic Data.

Preterm birth (PTB) is a phenomenon that brings risks and challenges for the survival of the newborn child. Despite many advances in research, not all the causes of PTB are already clear. It is understood that PTB risk is multi-factorial and can also be associated with socioeconomic factors. Thereby, this article seeks to use unsupervised learning techniques to stratify PTB risk in Brazil using only socioeconomic data. Through the use of datasets made publicly available by the Federal Government of Brazil, a new dataset was generated with municipality-level socioeconomic data and a PTB occurrence rate. This dataset was processed using various unsupervised learning techniques, such as k-means, principal component analysis (PCA), and density-based spatial clustering of applications with noise (DBSCAN). After validation, four clusters with high levels of PTB occurrence were discovered, as well as three with low levels. The clusters with high PTB were comprised mostly of municipalities with lower levels of education, worse quality of public services-such as basic sanitation and garbage collection-and a less white population. The regional distribution of the clusters was also observed, with clusters of high PTB located mostly in the North and Northeast regions of Brazil. The results indicate a positive influence of the quality of life and the offer of public services on the reduction in PTB risk.

Differences in risk factors for incident and recurrent preterm birth: a population-based linkage of 3.5 million births from the CIDACS birth cohort.

BACKGROUND: Preterm birth (PTB) is a syndrome resulting from a complex list of underlying causes and factors, and whether these risk factors differ in the context of prior PTB history is less understood. The aim of this study was to explore whether PTB risk factors in a second pregnancy were different in women with versus without previous PTB. METHODS: We conducted a population-based cohort study using data from the birth cohort of the Center for Data and Knowledge Integration for Health (CIDACS) for the period 2001 to 2015. We used longitudinal transition models with multivariate logistic regression to investigate whether risk factors varied between incident and recurrent PTB. RESULTS: A total of 3,528,050 live births from 1,764,025 multiparous women were analyzed. We identified different risk factors (Pdifference <0.05) between incident and recurrent PTB. The following were associated with an increased chance for PTB incidence, but not recurrent: household overcrowding (OR 1.09), maternal race/ethnicity [(Black/mixed-OR 1.04) and (indigenous-OR 1.34)], young maternal age (14 to 19 years-OR 1.16), and cesarean delivery (OR 1.09). The following were associated with both incident and recurrent PTB, respectively: single marital status (OR 0.85 vs 0.90), reduced number of prenatal visits [(no visit-OR 2.56 vs OR 2.16) and (1 to 3 visits-OR 2.44 vs OR 2.24)], short interbirth interval [(12 to 23 months-OR 1.04 vs OR 1.22) and (<12 months, OR 1.89, 95 vs OR 2.58)], and advanced maternal age (35-49 years-OR 1.42 vs OR 1.45). For most risk factors, the point estimates were higher for incident PTB than recurrent PTB. CONCLUSIONS: The risk factors for PTB in the second pregnancy differed according to women's first pregnancy PTB status. The findings give the basis for the development of specific prevention strategies for PTB in a subsequent pregnancy.

Hyperandrogenism and Polycystic ovary syndrome: Effects in pregnancy and offspring development.

Polycystic ovary syndrome (PCOS) is one of the major endocrine disorders affecting women of reproductive age. Its etiology remains unclear. It is suggested that environmental factors, and particularly the intrauterine environment, play key roles in PCOS development. Besides the role of androgens in PCOS pathogenesis, exposure to endocrine disruptors, as is Bisphenol A, could also contribute to its development. Although PCOS is considered one of the leading causes of ovarian infertility, many PCOS patients can get pregnant. Some of them by natural conception and others by assisted reproductive technique treatments. As hyperandrogenism (one of PCOS main features) affects ovarian and uterine functions, PCOS women, despite reaching pregnancy, could present high-risk pregnancies, including implantation failure, an increased risk of gestational diabetes, preeclampsia, and preterm birth. Moreover, hyperandrogenism may also be maintained in these women during pregnancy. Therefore, as an altered uterine milieu, including hormonal imbalance, could affect the developing organisms, monitoring these patients throughout pregnancy and their offspring development is highly relevant. The present review focuses on the impact of androgenism and PCOS on fertility issues and pregnancy-related outcomes and offspring development. The evidence suggests that the increased risk of pregnancy complications and adverse offspring outcomes of PCOS women would be due to the factors involved in the syndrome pathogenesis and the related co-morbidities. A better understanding of the involved mechanisms is still needed and could contribute to a better management of these women and their offspring. This article is categorized under: Reproductive System Diseases > Molecular and Cellular Physiology Reproductive System Diseases > Environmental Factors.

Association Between Neonatal Phototherapy Exposure and Childhood Neoplasm.

OBJECTIVE: To study the association between phototherapy for the treatment of neonatal jaundice and the risk of childhood neoplasms. STUDY DESIGN: This population-based retrospective cohort study included all infants born at ≥32 weeks of gestation at a single medical center between 1988 and 2018. The incidence of neoplastic diseases was compared between infants exposed to phototherapy and those unexposed. Kaplan-Meier curves and log-rank tests were used for cumulative incidence comparison, and multivariable Cox and Weibull survival analysis were used to adjust for confounding or clinically significant variables. RESULTS: The study population included 342 172 infants, of whom 18 797 (5.5%) were exposed to phototherapy. The median duration of follow-up was 9.5 years (range, birth to 18 years). Phototherapy was associated with a significantly increased risk for childhood malignancies and benign tumors (preterm birth and maternal age-adjusted hazard ratio, 1.89 [95% CI, 1.35-2.67] for malignancies and 1.27 [95% CI, 1.02-1.57] for benign tumors) Specifically, phototherapy was associated with hematopoietic cancers and leukemia (hazard ratio, 2.29 [95% CI, 1.48-3.54; P < .01] for hematopoietic cancers and 2.51 [95% CI, 1.52-4.14; P < .001] for leukemia), but not with solid tumors and lymphoma. CONCLUSIONS: Phototherapy may be associated with a slightly increased childhood risk of neoplasm. It is important to strictly follow phototherapy treatment guidelines to minimize unnecessary exposure.