No Association Was Found Between Mild Iodine Deficiency During Pregnancy and Pregnancy Outcomes: a Follow-up Study Based on a Birth Registry

Background Severe iodine deficiency during gestation is associated with adverse pregnancy outcomes; however, the impact of mild-to-moderate iodine deficiency, though prevalent in pregnancy, remains unclear. Methods We extracted follow-up data for 7435 pregnant women from a national iodine deficiency disorders monitoring program from 2016 to 2018 and a mother–child cohort study in 2017 based on a birth registry in Shanghai. Birth outcomes were collected from the registry. Spot urine and household salt samples were collected for iodine testing. Single-factor analysis and logistic regression were used to evaluate the association between maternal iodine status and pregnancy outcomes. Results The median urine iodine level in pregnant women was 137.5 μg/L (interquartile range 82.4–211.5), suggesting mild deficiency according to WHO standards. The incidence of pregnancy termination, preterm birth, congenital malformations, low birth weight, and cesarean section was 3.2%, 4.3%, 1.4%, 2.7%, and 45.2% in the mildly iodine-deficient group and 3.4%, 4.5%, 1.4%, 2.7%, and 44.5% in the normal group, respectively. After adjusting for maternal age and education, trimesters, and preterm birth rate in the general population, the odds ratios for any outcome did not differ significantly between the two groups. Conclusion The present study suggests that mild maternal iodine deficiency is not associated with adverse pregnancy outcomes.

Epidemiology of Antepartum Stillbirths in Austria—A Population-Based Study between 2008 and 2020

(1) Background: Across Europe, the incidence of antepartum stillbirth varies greatly, partly because of heterogeneous definitions regarding gestational weeks and differences in legislation. With this study, we sought to provide a comprehensive overview on the demographics of antepartum stillbirth in Austria, defined as non-iatrogenic fetal demise ≥22+0 gestational weeks (/40). (2) Methods: We conducted a population-based study on epidemiological characteristics of singleton antepartum stillbirth in Austria between January 2008 and December 2020. Data were derived from the validated Austrian Birth Registry. (3) Results: From January 2008 through December 2020, the antepartum stillbirth rate ≥20+0/40 was 3.10, ≥22+0/40 3.14, and ≥24+0/40 2.83 per 1000 births in Austria. The highest incidence was recorded in the federal states of Vienna, Styria, and Lower and Upper Austria, contributing to 71.9% of all stillbirths in the country. In the last decade, significant fluctuations in incidence were noted: from 2011 to 2012, the rate significantly declined from 3.40 to 3.07‰, whilst it significantly increased from 2.76 to 3.49‰ between 2019 and 2020. The median gestational age of antepartum stillbirth in Austria was 33+0 (27+2–37+4) weeks. Stillbirth rates ≤26/40 ranged from 164.98 to 334.18‰, whilst the lowest rates of 0.58–8.4‰ were observed ≥36/40. The main demographic risk factors were maternal obesity and low parity. (4) Conclusions: In Austria, the antepartum stillbirth rate has remained relatively stable at 2.83–3.10 per 1000 births for the last decade, despite a significant decline in 2012 and an increase in 2020.

Reproductive history and blood cell DNA methylation later in life: the Young Finns Study

Background Women with a history of complications of pregnancy, including hypertensive disorders, gestational diabetes or an infant fetal growth restriction or preterm birth, are at higher risk for cardiovascular disease later in life. We aimed to examine differences in maternal DNA methylation following pregnancy complications. Methods Data on women participating in the Young Finns study (n = 836) were linked to the national birth registry. DNA methylation in whole blood was assessed using the Infinium Methylation EPIC BeadChip. Epigenome-wide analysis was conducted on differential CpG methylation at 850 K sites. Reproductive history was also modeled as a predictor of four epigenetic age indices. Results Fourteen significant differentially methylated sites were found associated with both history of pre-eclampsia and overall hypertensive disorders of pregnancy. No associations were found between reproductive history and any epigenetic age acceleration measure. Conclusions Differences in epigenetic methylation profiles could represent pre-existing risk factors, or changes that occurred as a result of experiencing these complications.

Maternal Anxiety and Infants Birthweight and Length of Gestation. A sibling design

Background The overall aim of this study is to examine the effect of prenatal maternal anxiety on birthweight and gestational age, controlling for shared family confounding using a sibling comparison design. Methods The data on 77,970 mothers and their 91,165 children from the population-based Mother, Father and Child Cohort Study and data on 12,480 pairs of siblings were used in this study. The mothers filled out questionnaires for each unique pregnancy, at 17th and 30th week in pregnancy. Gestational age and birth weight was extracted from the Medical Birth Registry of Norway (MBRN). Associations between prenatal maternal anxiety (measured across the 17th and 30th weeks) and birth outcomes (birthweight and gestational age) were examined using linear regression with adjustment for shared-family confounding in a sibling comparison design. Results In the population level analysis the maternal anxiety score during pregnancy was inversely associated with new-born’s birthweight (Beta = -63.8 95% CI: -92.6, -35.0) and gestational age (Beta = -1.52, 95% CI: -2.15, -0.89) after adjustment for several covariates. The association of the maternal anxiety score with birthweight was no longer significant, but remained for maternal anxiety at 30th week with gestational age (Beta = -1.11, 95% CI: -1.82, -0.4) after further adjusting for the shared-family confounding in the sibling comparison design. Conclusion No association was found for maternal prenatal anxiety with birth weight after multiple covariates and family environment were controlled. However, there was an association between prenatal maternal anxiety at 30th week only with gestational age, suggesting a timing effect for maternal anxiety in third trimester.

Validating machine learning models for the prediction of labour induction intervention using routine data: a registry-based retrospective cohort study at a tertiary hospital in northern Tanzania

ObjectivesWe aimed at identifying the important variables for labour induction intervention and assessing the predictive performance of machine learning algorithms.SettingWe analysed the birth registry data from a referral hospital in northern Tanzania. Since July 2000, every birth at this facility has been recorded in a specific database.Participants21 578 deliveries between 2000 and 2015 were included. Deliveries that lacked information regarding the labour induction status were excluded.Primary outcomeDeliveries involving labour induction intervention.ResultsParity, maternal age, body mass index, gestational age and birth weight were all found to be important predictors of labour induction. Boosting method demonstrated the best discriminative performance (area under curve, AUC=0.75: 95% CI (0.73 to 0.76)) while logistic regression presented the least (AUC=0.71: 95% CI (0.70 to 0.73)). Random forest and boosting algorithms showed the highest net-benefits as per the decision curve analysis.ConclusionAll of the machine learning algorithms performed well in predicting the likelihood of labour induction intervention. Further optimisation of these classifiers through hyperparameter tuning may result in an improved performance. Extensive research into the performance of other classifier algorithms is warranted.

Joint Modeling of Singleton Preterm Birth and Perinatal Death Using Birth Registry Cohort Data in Northern Tanzania

Understanding independent and joint predictors of adverse pregnancy outcomes is essential to inform interventions toward achieving sustainable development goals. We aimed to determine the joint predictors of preterm birth and perinatal death among singleton births in northern Tanzania based on cohort data from the Kilimanjaro Christian Medical Center (KCMC) zonal referral hospital birth registry between 2000 and 2017. We determined the joint predictors of preterm birth and perinatal death using the random-effects models to account for the correlation between these outcomes. The joint predictors of higher preterm birth and perinatal death risk were inadequate (<4) antenatal care (ANC) visits, referred for delivery, experiencing pre-eclampsia/eclampsia, postpartum hemorrhage, low birth weight, abruption placenta, and breech presentation. Younger maternal age (15–24 years), premature rupture of membranes, placenta previa, and male children had higher odds of preterm birth but a lessened likelihood of perinatal death. These findings suggest ANC is a critical entry point for delivering the recommended interventions to pregnant women, especially those at high risk of experiencing adverse pregnancy outcomes. Improved management of complications during pregnancy and childbirth and the postnatal period may eventually lead to a substantial reduction of adverse perinatal outcomes and improving maternal and child health.

Caesarean section and its relationship to offspring general cognitive ability: a registry-based cohort study of half a million young male adults

BackgroundA relationship between caesarean section and offspring cognitive ability has been described, but data are limited, and a large-scale study is needed.ObjectiveTo determine the relationship between mode of delivery and general cognitive ability.MethodsA cohort of 579 244 singleton males, born between 1973 and 1987 who conscripted before 2006, were identified using the Swedish population-based registries. Their mode of delivery was obtained from the Swedish Medical Birth registry. The outcome measure was a normalised general cognitive test battery (mean 100, SD 15) performed at military conscription at around age 18.FindingsMales born by caesarean section performed poorer compared with those born vaginally (mean score 99.3 vs 100.1; adjusted mean difference −0.84; 95% CI −0.97 to −0.72; p<0.001). Both those born by elective (99.3 vs 100.2; −0.92; 95% CI −1.24 to −0.60; p<0.001) and non-elective caesarean section (99.2 vs 100.2; −1.03; 95% CI −1.34 to −0.72; p=0.001), performed poorer than those born vaginally. In sibling analyses, the association was attenuated to the null (100.9 vs 100.8; 0.07; 95% CI −0.31 to 0.45; p=0.712). Similarly, neither elective nor non-elective caesarean section were associated with general cognitive ability in sibling analyses.ConclusionBirth by caesarean section is weakly associated with a lower general cognitive ability in young adult males. However, the magnitude of this association is not clinically relevant and seems to be largely explained by familial factors shared between siblings.Clinical implicationClinicians and gravidas ought not to be concerned that the choice of mode of delivery will impact offspring cognitive ability.

Variation in disease in children according to immigrant background

Background: A growing proportion of children born in Europe are born to immigrant parents. Knowledge about their health is essential for preventive and curative medicine and health services planning. Objective: To investigate differences in diagnoses given in secondary and tertiary healthcare between Norwegian-born children to immigrant and non-immigrant parents. Methods: Data from the Medical Birth Registry of Norway, the Norwegian Patient Registry and Statistics Norway were linked by the national personal identification number. The study population included children born in Norway aged 0–10 years between 2008 and 2018 ( N=1,015,267). Diagnostic categories from three main domains of physical health, given in secondary or tertiary care; infections, non-infectious medical conditions and non-infectious neurological conditions were included from 2008 onwards. Hazards of diagnoses by immigrant background were assessed by Cox regressions adjusted for sex and birth year. Results: Children of immigrants generally had higher hazards than children with Norwegian background of some types of infections, obesity, nutrition-related disorders, skin diseases, blood disease and genital disease. Children of immigrants from Africa also had higher hazards of cerebral palsy, cerebrovascular diseases and epilepsy. Conversely, most groups of children of immigrants had lower hazards of acute lower respiratory tract infections, infections of the musculoskeletal system, infections of the central nervous system, diseases of the circulatory system, hearing impairment, immune system disorders, chronic lower respiratory disease and headache conditions. Conclusions: Children of immigrants did not present with overall worse health than children without immigrant background, but the distribution of health problems varied between groups.