Structured Measurement Error in Nutritional Epidemiology

BackgroundWomen with systemic lupus erythematosus (SLE) are known to have more difficulty in achieving a successful pregnancy than healthy women. They have a higher risk for adverse pregnancy outcomes (APOs)...

BackgroundPreterm birth is the most important cause of neonatal morbidity and mortality. Clinical guidelines recommend assessment of risk of preterm birth and implementation of interventions to reduce preterm birth risk through dedicated preterm birth clinics. We hypothesized that a two-tier preterm birth clinic pathway can safely manage women at the highest risk of preterm birth while reducing intervention for women at moderate risk of preterm birth. We aimed to test this hypothesis by evaluating risk factors, management, and outcomes of women attending a two-tier preterm birth prevention service.MethodsWe conducted a retrospective cohort study of women who gave birth between January and June 2021 at a tertiary hospital in Oxford, UK. We included two cohorts: women attending a Cervical Screening Clinic and women attending a Preterm Birth Clinic, and we also reviewed all cases of births before 34 weeks over that time period. At the initial midwife appointment at 8–10 weeks’ gestation, risk factors for preterm birth were assessed. Pregnant women with moderate risk factors (previous preterm birth at 32+ 0 − 33+ 6 weeks, previous preterm prelabour rupture of membranes (PPROM) at 32+ 0 − 33+ 6 weeks, previous LLETZ / cone biopsy, known abnormal uterus, previous caesarean section at 10 cm dilatation, and multiple pregnancy) were referred to the Cervical Screening Clinic for a cervical length scan by a sonographer. Pregnant women with major risk factors (previous preterm birth at 16+ 0 − 31+ 6 weeks, previous PPROM at less than 32+ 0 weeks, radical trachelectomy, previous cervical cerclage) as well as those with a cervix < 25 mm at any scan were referred to the Preterm Birth Clinic for a cervical length scan and counselling by a specialist obstetrician. Detailed information on risk factors, management, and perinatal outcomes were collected from case notes and analysed.Results189 women attended the Cervical Screening Clinic: 79.1% had a moderate risk factor for preterm birth, 100% had a cervical length scan, 7% had a short cervix and 4.2% received an intervention. All 196 infants were live born, with overall preterm birth rates of 14.8% at < 37 weeks, 3.1% at < 32 weeks, and 0% at < 28 weeks. The spontaneous live preterm birth rates were 9.7% at < 37 weeks, 2.6% at < 32 weeks and 0% at < 28 weeks. 79 women attended the Preterm Birth Clinic: 87.3% had a major risk factor for preterm birth, 100% had ≥ 1 cervical length scan, 41.3% had a short cervix, 78.1% received vaginal progesterone, and 39% had a cervical cerclage. Overall preterm birth rates were 33.8% at < 37 weeks, 10.3% at < 32 weeks and 4.4% at < 28 weeks. Spontaneous live preterm birth rates were 22.1% at < 37 weeks, 7.4% at < 32 weeks, and 2.9% at < 28 weeks. 115 women gave birth to 130 babies before 34 weeks: 80% had no major risk factor for preterm birth, 29% had a cervical length scan and less than 15% had an intervention. Over 90% had a live birth, but the neonatal death rate was high (8.5%).ConclusionWomen with moderate risk factors for preterm birth seen in the Cervical Screening Clinic had low rates of intervention and good perinatal outcomes. Most women with major risk factors were appropriately referred and managed by the Preterm Birth Clinic. This two-tier preterm birth prevention service therefore appears safe and effective.

A Semi-Quantitative Food Frequency Questionnaire Validated in Hispanic Infants and Toddlers Aged 0 to 24 Months

Preterm birth is a significant global public health issue. It is defined by the World Health Organization as infants born alive before 37 completed weeks of gestation. The preterm birth rate varies significantly across countries and regions. Globally, an estimated 13.4 million babies were born preterm in 2020 (i.e., 1 in 10 babies worldwide was preterm birth). It is the leading cause of under-5 child mortality worldwide, and preterm infants are particularly vulnerable to respiratory complications, feeding difficulty, poor body temperature regulation, and high risk of infection. Both genetic and nongenetic factors (exposome factors) contribute to the risk of preterm birth. Social and behavioral factors, medical and pregnancy conditions, and environmental exposures are common nongenetic risk factors for preterm birth. Individuals from certain ethnic and racial groups, in low- and middle-income countries, or with a low socioeconomic status are at an increased risk of having preterm birth, and social determinants of health are the root causes of these factors. Existing pregnancy complications, history of preterm birth, and other medical conditions are also common risk factors. Environmental exposures such as air pollution, climate change, and endocrine-disrupting chemicals have been increasingly realized as potential risk factors for preterm birth. Various pathological events in different feto-maternal systems have been reported to be involved in the development of preterm birth. Immunopathogenesis plays a pivotal role, and both pathogenic and nonpathogenic inflammation can induce preterm birth. Oxidative stress, decidual hemorrhage and vascular lesions, uterine overdistension, and cervical insufficiency have all been proposed to contribute to the pathophysiology of preterm birth. Prevention strategies for preterm birth include primary prevention aimed at the modifiable risk factors at the individual and societal levels and therapeutic approaches using pharmaceuticals and mechanical interventions, such as progesterone and cervical cerclage. A comprehensive approach is still needed to reduce the global disease burden of preterm birth.

In the province of Manitoba, the incidence of preterm birth has been increasing and the rate is higher among Aboriginal than non-Aboriginal women. The purpose of this study was to identify risk factors for spontaneous preterm birth in Manitoba women, and to compare risk factors among Aboriginal and non-Aboriginal women. A case-control study was performed at two tertiary care hospitals in Winnipeg, Manitoba, Canada from October 1999 to December 2000. Cases delivered a live singleton infant at < 37 weeks gestation (n = 226; 36% Aboriginal), while controls delivered between 37 and 42 weeks gestation (n = 458; 38% Aboriginal). An interview was conducted with each subject on the postpartum unit, and information was collected from the health record. Using stratified analyses to control for race/ethnicity, several risk factors for preterm birth had a uniform effect measure across strata, while others demonstrated heterogeneity. After adjusting for other maternal characteristics in a multivariable logistic regression model, significant risk factors for all women included previous preterm birth, two or more previous spontaneous abortions, vaginal bleeding after 12 weeks gestation, gestational hypertension, antenatal hospitalisation, and prelabour rupture of membranes. In addition, potentially modifiable risk factors included low weight gain during pregnancy and inadequate prenatal care for all women, and high levels of perceived stress for Aboriginal women. These modifiable risk factors lend themselves to public health interventions, and should be targeted in future prevention efforts.

Preterm birth constitutes a significant international public health issue, with implications for child and family well-being. High levels of psychosocial stress and negative affect before and during pregnancy are contributing factors to shortened gestation and preterm birth. We developed a cumulative psychosocial stress variable and examined its association with early delivery controlling for known preterm birth risk factors and confounding environmental variables. We further examined this association among subgroups of women with different levels of coping resources. Utilizing the All Our Babies (AOB) study, an ongoing prospective pregnancy cohort study in Alberta, Canada (n = 3,021), multinomial logistic regression was adopted to examine the independent effect of cumulative psychosocial stress and preterm birth subgroups compared to term births. Stratified analyses according to categories of perceived social support and optimism were undertaken to examine differential effects among subgroups of women. Cumulative psychosocial stress was a statistically significant risk factor for late preterm birth (OR = 1.73; 95% CI = 1.07, 2.81), but not for early preterm birth (OR = 2.44; 95% CI = 0.95, 6.32), controlling for income, history of preterm birth, pregnancy complications, reproductive history, and smoking in pregnancy. Stratified analyses showed that cumulative psychosocial stress was a significant risk factor for preterm birth at <37weeks gestation for women with low levels of social support (OR = 2.09; 95% CI = 1.07, 4.07) or optimism (OR = 1.87; 95% CI = 1.04, 3.37). Our analyses suggest that early vulnerability combined with current anxiety symptoms in pregnancy confers risk for preterm birth. Coping resources may mitigate the effect of cumulative psychosocial stress on the risk for early delivery.

Objective. To investigate the prevalence and to identify risk factors for live singleton preterm birth in Omdurman Maternity hospital, Sudan.Methods. Case–control study. Odds ratios were adjusted for the confounding factors using multiple logistic regression models.Results. Among 3240 live birth at maternity hospital during the 3 months period of the study, 126 (3.8%) were a live preterm birth. About 99 live preterm births at a mean (SD) of 32.7 (2.2) gestational weeks were included in the final analyses. About 80 (81.0%) of these 99 preterm births were spontaneous preterm births and the rest 19 (19.0%) were medically indicated preterm births. Univariate and Multivariate analyses showed that those women who had history of miscarriage, preterm birth, cesarean delivery, dental maneuver, and vaginal bleeding in the index pregnancy, both low body mass index (BMI) (<25) and high BMI (>30) and those women who had short interpregancy interval were at higher risk for preterm birth.Conclusions. The study showed that spontaneous preterm birth predominates in this setting. Preterm birth has a tendency to recur. Infections (periodontal) and nutrition were the risk factors for preterm birth. More research is needed especially in the area of nutrition and oral hygiene.

Assessment of risk factors and predictors for spontaneous pre-term birth in a South Indian antenatal cohort

In vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI) is associated with an increased risk of preterm (33rd–37th gestational week) and early preterm birth (20th–32nd gestational week). The underlying general and procedure related risk factors are not well understood so far. 4328 infertile women undergoing IVF/ICSI were entered into this study. The study population was divided into three groups: (a) early preterm birth group (n = 66), (b) preterm birth group (n = 675) and (c) full-term birth group (n = 3653). Odds for preterm birth were calculated by stepwise multivariate logistic regression analysis. We identified seven independent risk factors for preterm birth and four independent risk factors for early preterm birth. Older (> 39) or younger (< 25) maternal age (OR: 1.504, 95% CI 1.108–2.042, P = 0.009; OR: 2.125, 95% CI 1.049–4.304, P = 0.036, respectively), multiple pregnancy (OR: 9.780, 95% CI 8.014–11.935, P < 0.001; OR: 8.588, 95% CI 4.866–15.157, P < 0.001, respectively), placenta previa (OR: 14.954, 95% CI 8.053–27.767, P < 0.001; OR: 16.479, 95% CI 4.381–61.976, P < 0.001, respectively), and embryo reduction (OR: 3.547, 95% CI 1.736–7.249, P = 0.001; OR: 7.145, 95% CI 1.990–25.663, P = 0.003, respectively) were associated with preterm birth and early preterm birth, whereas gestational hypertension (OR: 2.494, 95% CI 1.770–3.514, P < 0.001), elevated triglycerides (OR: 1.120, 95% CI 1.011–1.240, P = 0.030) and shorter activated partial thromboplastin time (OR: 0.967, 95% CI 0.949–0.985, P < 0.001) were associated only with preterm birth. In conclusion, preterm and early preterm birth risk factors in patients undergoing assisted IVF/ICSI are in general similar to those in natural pregnancy. The lack of some associations in the early preterm group was most likely due to the lower number of early preterm birth cases. Only embryo reduction represents an IVF/ICSI specific risk factor.

Preterm birth is a heterogeneous condition with multiple underlying causes, and periodontal diseases are one of them. Approximately 900000 preterm births are reported in Pakistan each year. Oral infections such as periodontitis during pregnancy are associated with adverse pregnancy outcomes such as low birth weight and preterm births. However, different studies have reported contradictory findings. We conducted a cross-sectional study to assess the association of preterm birth with oral infection in pregnancy. We conducted a cross-sectional analytical study on 400 postpartum pregnant women in Khyber Teaching Hospital, Peshawar. Only women within the age bracket of 18‒40 years were recruited. Data were collected by an interview-based structured questionnaire. The extent and severity index were used to assess the periodontal health of participants. Frequency tables were generated, and the chi-squared test was used to determine associations between different categorical variables. The mean age of the participants was 25.8±4.9 years. Approximately 87.5% of the women had generalized periodontitis. Approximately 68% of mothers had moderate severity of periodontitis. The extent index showed no notable difference between the preterm and full-term birth groups. In contrast, the severity index displayed a statistically significant difference between the preterm and full-term birth groups. The majority of women had generalized periodontitis. The severity index demonstrated a significant association between maternal periodontitis and preterm births. There was no association between the age of mothers and preterm births. Complications in pregnancy were not associated with preterm births.

Although the specific pathogenesis of preterm birth (PTB) has not been thoroughly clarified, it is known to be related to various factors, such as pregnancy complications, maternal socioeconomic factors, lifestyle habits, reproductive history, environmental and psychological factors, prenatal care, and nutritional status. PTB has serious implications for newborns and families and is associated with high mortality and complications. Therefore, the prediction of PTB risk can facilitate early intervention and reduce its resultant adverse consequences. To analyze the risk factors for PTB to establish a PTB risk prediction model and to assess postpartum anxiety and depression in mothers. A retrospective analysis of 648 consecutive parturients who delivered at Shenzhen Bao'an District Songgang People's Hospital between January 2019 and January 2022 was performed. According to the diagnostic criteria for premature infants, the parturients were divided into a PTB group (n = 60) and a full-term (FT) group (n = 588). Puerperae were assessed by the Self-rating Anxiety Scale (SAS) and Self-rating Depression Scale (SDS), based on which the mothers with anxiety and depression symptoms were screened for further analysis. The factors affecting PTB were analyzed by univariate analysis, and the related risk factors were identified by logistic regression. According to univariate analysis, the PTB group was older than the FT group, with a smaller weight change and greater proportions of women who underwent artificial insemination and had gestational diabetes mellitus (P < 0.05). In addition, greater proportions of women with reproductive tract infections and greater white blood cell (WBC) counts (P < 0.05), shorter cervical lengths in the second trimester and lower neutrophil percentages (P < 0.001) were detected in the PTB group than in the FT group. The PTB group exhibited higher postpartum SAS and SDS scores than did the FT group (P < 0.0001), with a higher number of mothers experiencing anxiety and depression (P < 0.001). Multivariate logistic regression analysis revealed that a greater maternal weight change, the presence of gestational diabetes mellitus, a shorter cervical length in the second trimester, a greater WBC count, and the presence of maternal anxiety and depression were risk factors for PTB (P < 0.01). Moreover, the risk score of the FT group was lower than that of the PTB group, and the area under the curve of the risk score for predicting PTB was greater than 0.9. This study highlights the complex interplay between postpartum anxiety and PTB, where maternal anxiety may be a potential risk factor for PTB, with PTB potentially increasing the incidence of postpartum anxiety in mothers. In addition, a greater maternal weight change, the presence of gestational diabetes mellitus, a shorter cervical length, a greater WBC count, and postpartum anxiety and depression were identified as risk factors for PTB.

Background: Preterm birth, delivery prior to 37 completed weeks or 259 days gestation, is a worldwide maternal and perinatal challenge and is a leading cause of neonatal morbidity and mortality. Preterm birth remains the leading cause of perinatal and postnatal mortality and morbidity especially in developing countries where the health care services are suffering from limited resources. Premature babies usually suffer from both immediate and long term consequences. Right after birth, they have difficulties in breathing, temperature regulation, bleeding, infection and other problems due to organ immaturity. Their growth and developmental milestones will also be affected leading poor physical, mental, educational and psychosocial problems as a long term consequences. Preterm deliveries were responsible for 1 million out of the 6.3 million deaths of children under5 in2013 REF _Ref493689700 \r \h \* MERGEFORMAT [1]. In Kenyatta National hospital, few studies have been carried out to determine the prevalence and factors associated with preterm birth. Hence the aim of this study is to determine the prevalence and factors associated with preterm birth at Kenyatta national hospital (KNH), Nairobi, Kenya. Materials and Methods: This was a hospital based descriptive cross-sectional study involving randomly selected respondents (N = 183) from post natal ward of Kenyatta National Hospital. Systematic random sampling method was applied to recruit the study respondents. A pre-tested semi-structured questionnaire was employed to collect information on the possible determinants of Preterm birth. Data was analysed usingSPSSsoftware version 22.0. Descriptive analysis was done using mean and frequency proportion. Inferential analysis using chi-square test was used to establish association different variables. The ethical approval to conduct the study was obtained from KNH-University of Nairobi Ethical Review Committee (KNH-UoN ERC). Permission to collect data was sought from the KNH and consent was obtained from the selected respondents before administering the questionnaire. Result: The prevalence rate of preterm birth was 20.2%. History of urinary tract infection during pregnancy [AOR = 4.62; 95% CI = 1.56 - 4.67; P = 0.013], history of preterm birth [AOR = 5.8; 95% CI = 1.18 - 10.30; P = 0.001], history of abortion [AOR = 3.54; 95% CI = 1.18 - 10.41; P = 0.016], history of hypertension during pregnancy [AOR = 2.04; 95% CI = 1.14 - 3.64; P = 0.012], maternal age (≥31 years) [AOR = 2.81; 95% CI = 1.24 - 5.87; P = 0.012] and alcohol consumption during pregnancy [AOR = 2.56; 95% CI = 0.68 - 9.64; P = 0.014] were determined as significant risk factors for preterm birth. Conclusion and recommendation: The determinants of preterm birth are multifactorial including history of abortion, preterm birth, urinary tract infection, hypertension and alcohol consumption during pregnancy. Most of these risk factors of preterm birth are controllable if reproductive age mothers are educated properly. It is very important for antenatal mothers to adhere to the guidelines of antenatal visits so that those at risk are spotted and close monitoring can done in order to reduce this high rate of preterm birth and its negative consequences. Strategies to avert the high prevalence of preterm birth and its associated morbidity and mortality must be given priority at national, regional and international levels, so that the Millennium Development Goal (MDG) 4 can be achieved.

BackgroundPreterm birth, the birth of an infant prior to 37 completed weeks of gestation, is the leading cause of perinatal morbidity and mortality. Preterm infants are at greater risk of respiratory, gastrointestinal and neurological diseases. Despite significant research in developed countries, little is known about the causes of preterm birth in many developing countries, especially China. This study investigates the association between sciodemographic data, obstetric risk factor, and preterm birth in five Maternal and Child Health hospitals in Beijing, China.Methods and FindingsA case-control study was conducted on 1391 women with preterm birth (case group) and 1391 women with term delivery (control group), who were interviewed within 48 hours of delivery. Sixteen potential factors were investigated and statistical analysis was performed by univariate analysis and logistic regression analysis. Univariate analysis showed that 14 of the 16 factors were associated with preterm birth. Inter-pregnancy interval and inherited diseases were not risk factors. Logistic regression analysis showed that obesity (odds ratio (OR) = 3.030, 95% confidence interval (CI) 1.166–7.869), stressful life events (OR = 5.535, 95%CI 2.315–13.231), sexual activity (OR = 1.674, 95%CI 1.279–2.191), placenta previa (OR 13.577, 95%CI 2.563–71.912), gestational diabetes mellitus (OR = 3.441, 95%CI1.694–6.991), hypertensive disorder complicating pregnancy (OR = 6.034, 95%CI = 3.401–10.704), history of preterm birth (OR = 20.888, 95%CI 2.519–173.218) and reproductive abnormalities (OR = 3.049, 95%CI 1.010–9.206) were independent risk factors. Women who lived in towns and cities (OR = 0.603, 95%CI 0.430–0.846), had a balanced diet (OR = 0.533, 95%CI 0.421–0.675) and had a record of prenatal care (OR = 0.261, 95%CI 0.134–0.510) were less likely to have preterm birth.ConclusionsObesity, stressful life events, sexual activity, placenta previa, gestational diabetes mellitus, hypertensive disorder complicating pregnancy, history of preterm birth and reproductive abnormalities are independent risk factors to preterm birth. Identification of remedial factors may inform local health and education policy.

Twin birth weight discordance and risk of preterm birth

This study aimed to compare the similarities and differences among Food Frequency Questionnaire(FFQ), 24-hour dietary recall method, and weighing method in assessing the intakes of foods, energy, and nutrients in pregnant women, and to evaluate the validity of the FFQ. From June to September in 2017, a total of 82 pregnant women were recruited across the entire Wuqiang County in Hebei Province. The subjects were surveyed using the FFQ for the most recent week, 24-hour dietary recall for 3 consecutive days, and in-home weighing for 3 consecutive days. The differences in the average daily intakes of food, energy, and nutrients obtained by the FFQ and the other two method were calculated and compared. The correlation and consistency between the FFQ and the other two method were evaluated through the Spearman correlation coefficient and the Bland-Altman plot, respectively. There was no statistically significant difference between the FFQ and 24-hour dietary recall method in assessing the average daily intakes of soybeans and their products, fruits, dairy products and nuts. The intakes of fruits and dairy products evaluated by the two method were all positively correlated(r=0.34-0.56, P&lt;0.05). There was no statistically significant difference between the FFQ and the weighing method in assessing the average daily intakes of cereals, soybeans and their products, vegetables, fruits, aquatic products, eggs, dairy products and nuts. Among them, the intakes obtained by the two method for cereals, vegetables and nuts were all positively correlated(r=0.53-0.58, P&lt;0.05). There was no statistically significant difference between the FFQ and 24-hour dietary recall method in evaluating average daily intakes of energy, protein, carbohydrates, the ratio of carbohydrates to energy supply, dietary fiber, total vitamin A, thiamine, riboflavin, vitamin C, calcium, phosphorus, potassium, magnesium, iron and zinc. Among them, intakes of energy, protein, fat and carbohydrates were all positively correlated(r=0.41-0.58, P&lt;0.05). There was no statistically significant difference between FFQ and weighing method in evaluating the average daily intakes of energy, fat, the ratio of fat to energy supply, carbohydrates, the ratio of carbohydrates to energy supply, total vitamin A, thiamine, riboflavin, vitamin C, calcium, potassium, sodium and magnesium. Among them, the intakes of energy, protein and carbohydrates obtained by the two method were all positively correlated(r=0.49-0.52, P&lt;0.05). Bland-Altman analysis showed that for most subjects, the intakes of energy, protein, fat and carbohydrates were within the 95% consistency limits between FFQ and 24-hour recall method(91.1%-94.9%)or weighing method(92.9%-100%). FFQ can relatively accurately evaluate the intakes of food and nutrients among pregnant women.