Association between cumulative maternal exposures related to inflammation and child attention-deficit/hyperactivity disorder: A cohort study.

BACKGROUND: Preclinical studies suggest synergistic effects of maternal inflammatory exposures on offspring neurodevelopment, but human studies have been limited. OBJECTIVES: To examine the cumulative association and potential interactions between seven maternal exposures related to inflammation and child attention-deficit/hyperactivity disorder (ADHD). METHODS: We conducted a population-based cohort study of children born from July 2001 to December 2011 in New South Wales, Australia, and followed up until December 2014. Seven maternal exposures were identified from birth data and hospital admissions during pregnancy: autoimmune disease, asthma, hospitalization for infection, mood or anxiety disorder, smoking, hypertension, and diabetes. Child ADHD was identified from stimulant prescription records. Multivariable Cox regression assessed the association between individual and cumulative exposures and ADHD and potential interaction between exposures, controlling for potential confounders. RESULTS: The cohort included 908,770 children, one-third (281,724) with one or more maternal exposures. ADHD was identified in 16,297 children (incidence 3.5 per 1000 person-years) with median age of 7 (interquartile range 2) years at first treatment. Each exposure was independently associated with ADHD, and risk increased with additional exposures: one exposure (hazard ratio (HR) 1.59, 95% confidence interval (CI) 1.54, 1.65), two exposures (HR 2.25, 95% CI 2.13, 2.37), and three or more exposures (HR 3.28, 95% CI 2.95, 3.64). Positive interaction was found between smoking and infection. The largest effect size was found for cumulative exposure of asthma, infection, mood or anxiety disorder, and smoking (HR 6.12, 95% CI 3.47, 10.70). CONCLUSIONS: This study identifies cumulative effects of multiple maternal exposures related to inflammation on ADHD, most potentially preventable or modifiable. Future studies should incorporate biomarkers of maternal inflammation and consider gene-environment interactions.

Neonatal outcomes and follow-up of children born to women with pregnancy-associated cancer: a prospective observational study.

BACKGROUND: During the last decade, there has been a growing number of cases of children born from pregnancy-associated cancer (PAC), however there are currently insufficient data on the follow up to be observed in this category of newborns. Objective of the study was to evaluate the neonatal outcomes of infants born to mother with PAC, the potential adverse effect of chemotherapy during pregnancy and the risk of metastasis to the fetus. METHODS: Maternal clinical data and neonatal outcomes of child born to mothers diagnosed with PAC were collected; infants were divided into those were and were not exposed to chemotherapy during fetal life and their outcomes were compered. RESULTS: A total of 37 newborn infants from 36 women with PAC were analyzed. Preterm delivery occurred in 83.8% of the cases. No significant differences in neonatal outcomes were found between infants who were and were not exposed to chemotherapy during pregnancy. The median follow-up period was 12 months. CONCLUSIONS: PAC treatment during the second or third trimester does not seem to be dangerous for the fetus, however infants born from PAC must be carefully evaluated for to rule out the consequences of chemotherapy and exclude the presence of metastasis. Long-term follow-up, especially in children exposed to chemotherapy, should be encouraged to obtain relevant data on long-term toxicity.

The Pregnancy, Arsenic, and Immune Response (PAIR) Study in rural northern Bangladesh.

BACKGROUND: Arsenic exposure and micronutrient deficiencies may alter immune reactivity to influenza vaccination in pregnant women, transplacental transfer of maternal antibodies to the foetus, and maternal and infant acute morbidity. OBJECTIVES: The Pregnancy, Arsenic, and Immune Response (PAIR) Study was designed to assess whether arsenic exposure and micronutrient deficiencies alter maternal and newborn immunity and acute morbidity following maternal seasonal influenza vaccination during pregnancy. POPULATION: The PAIR Study recruited pregnant women across a large rural study area in Gaibandha District, northern Bangladesh, 2018-2019. DESIGN: Prospective, longitudinal pregnancy and birth cohort. METHODS: We conducted home visits to enrol pregnant women in the late first or early second trimester (11-17 weeks of gestational age). Women received a quadrivalent seasonal inactivated influenza vaccine at enrolment. Follow-up included up to 13 visits between enrolment and 3 months postpartum. Arsenic was measured in drinking water and maternal urine. Micronutrient deficiencies were assessed using plasma biomarkers. Vaccine-specific antibody titres were measured in maternal and infant serum. Weekly telephone surveillance ascertained acute morbidity symptoms in women and infants. PRELIMINARY RESULTS: We enrolled 784 pregnant women between October 2018 and March 2019. Of 784 women who enrolled, 736 (93.9%) delivered live births and 551 (70.3%) completed follow-up visits to 3 months postpartum. Arsenic was detected (≥0.02 µg/L) in 99.7% of water specimens collected from participants at enrolment. The medians (interquartile ranges) of water and urinary arsenic at enrolment were 5.1 (0.5, 25.1) µg/L and 33.1 (19.6, 56.5) µg/L, respectively. Water and urinary arsenic were strongly correlated (Spearman's ⍴ = 0.72) among women with water arsenic ≥ median but weakly correlated (⍴ = 0.17) among women with water arsenic < median. CONCLUSIONS: The PAIR Study is well positioned to examine the effects of low-moderate arsenic exposure and micronutrient deficiencies on immune outcomes in women and infants. REGISTRATION: NCT03930017.

Associations of prenatal maternal depressive symptoms with cord blood glucocorticoids and child hair cortisol levels in the project viva and the generation R cohorts: a prospective cohort study.

BACKGROUND: Prior studies have reported conflicting results regarding the association of prenatal maternal depression with offspring cortisol levels. We examined associations of high levels of prenatal depressive symptoms with child cortisol biomarkers. METHODS: In Project Viva (n = 925, Massachusetts USA), mothers reported their depressive symptoms using the Edinburgh Postnatal Depression Scale (EPDS) during pregnancy, cord blood glucocorticoids were measured at delivery, and child hair cortisol levels were measured in mid-childhood (mean (SD) age: 7.8 (0.8) years) and early adolescence (mean (SD) age: 13.2 (0.9) years). In the Generation R Study (n = 1644, Rotterdam, The Netherlands), mothers reported depressive symptoms using the Brief Symptom Inventory (BSI) during pregnancy, and child hair cortisol was measured at a mean (SD) age of 6.0 (0.5) years. We used cutoffs of ≥ 13 for the EPDS and > 0.75 for the BSI to indicate high levels of prenatal depressive symptoms. We used multivariable linear regression models adjusted for child sex and age (at outcome), and maternal pre-pregnancy BMI, education, social support from friends/family, pregnancy smoking status, marital status, and household income to assess associations separately in each cohort. We also meta-analyzed childhood hair cortisol results from both cohorts. RESULTS: 8.0% and 5.1% of women respectively experienced high levels of prenatal depressive symptoms in Project Viva and the Generation R Study. We found no associations between high levels of maternal depressive symptoms during pregnancy and child cortisol biomarkers in either cohort. CONCLUSIONS: The present study does not find support for the direct link between high levels of maternal depressive symptoms and offspring cortisol levels.

Maternal autoimmune disease and risk of hospitalization for autoimmune disease, allergy, and cancer in offspring.

BACKGROUND: Children whose mothers have autoimmune disease may be at risk of developing immune-mediated disorders. We assessed the association between maternal autoimmune disease and risk of autoimmune disease, allergy, and cancer in offspring. METHODS: We analyzed a cohort of 1,011,623 children born in Canada between 2006 and 2019. We identified mothers who had autoimmune diseases and assessed hospitalizations for autoimmune disease, allergy, and cancer in offspring between birth and 14 years of age. We estimated hazard ratios (HR) for the association of maternal autoimmune disease with child hospitalization in adjusted Cox regression models. We used within-sibling analysis to control for genetic and environmental confounders. RESULTS: A total of 20,354 children (2.0%) had mothers with an autoimmune disease. Compared with no autoimmune disease, maternal autoimmune disease was associated with the risk of childhood hospitalization for autoimmune disease (HR 1.96, 95% CI 1.66-2.31) and allergy (HR 1.30, 95% CI 1.21-1.40), but was not significantly associated with cancer (HR 1.31, 95% CI 0.96-1.80). Type 1 diabetes, celiac disease, inflammatory arthritis, and systemic lupus erythematosus were among specific maternal autoimmune diseases most strongly associated with childhood hospitalization for autoimmune disease and allergy. The associations disappeared after controlling for genetic and environmental confounders in the within-sibling analysis. CONCLUSIONS: Maternal autoimmune disease is associated with an increased risk of autoimmune disease and allergy hospitalization in offspring, but the relationship appears to be confounded by genetic and environmental factors. Prenatal exposure to immunologic or pharmacologic products is not likely a direct cause of immune-mediated disease in children.

The impact of prenatal alcohol and/or tobacco exposure on brain structure in a large sample of children from a South African birth cohort.

BACKGROUND: Neuroimaging studies have emphasized the impact of prenatal alcohol exposure (PAE) on brain development, traditionally in heavily exposed participants. However, less is known about how naturally occurring community patterns of PAE (including light to moderate exposure) affect brain development, particularly in consideration of commonly occurring concurrent impacts of prenatal tobacco exposure (PTE). METHODS: Three hundred thirty-two children (ages 8 to 12) living in South Africa's Cape Flats townships underwent structural magnetic resonance imaging. During pregnancy, their mothers reported alcohol and tobacco use, which was used to evaluate PAE and PTE effects on their children's brain structure. Analyses involved the main effects of PAE and PTE (and their interaction) and the effects of PAE and PTE quantity on cortical thickness, surface area, and volume. RESULTS: After false-discovery rate (FDR) correction, PAE was associated with thinner left parahippocampal cortices, while PTE was associated with smaller cortical surface area in the bilateral pericalcarine, left lateral orbitofrontal, right posterior cingulate, right rostral anterior cingulate, left caudal middle frontal, and right caudal anterior cingulate gyri. There were no PAE × PTE interactions nor any associations of PAE and PTE exposure on volumetrics that survived FDR correction. CONCLUSION: PAE was associated with reduction in the structure of the medial temporal lobe, a brain region critical for learning and memory. PTE had stronger and broader associations, including with regions associated with executive function, reward processing, and emotional regulation, potentially reflecting continued postnatal exposure to tobacco (i.e., second-hand smoke exposure). These differential effects are discussed with respect to reduced PAE quantity in our exposed group versus prior studies within this geographical location, the deep poverty in which participants live, and the consequences of apartheid and racially and economically driven payment practices that contributed to heavy drinking in the region. Longer-term follow-up is needed to determine potential environmental and other moderators of the brain findings here and assess the extent to which they endure over time.

Parental occupational exposures in wood-related jobs and risk of testicular germ cell tumours in offspring in NORD-TEST a registry-based case-control study in Finland, Norway, and Sweden.

OBJECTIVE: We assessed the association between parental prenatal exposures in wood-related jobs and risk of testicular germ cell tumours (TGCT) in offspring. METHODS: NORD-TEST, a registry-based case-control study in Sweden, Finland and Norway, included 8112 TGCT cases diagnosed at ages 14-49 years between 1978 and 2012 with no history of prior cancer, and up to four controls matched to each case on year and country of birth. Parents of cases and controls were identified via linkages with the population registries and their occupational information was retrieved from censuses. The Nordic Occupational Cancer Study Job-Exposure Matrix was used to assign occupational exposures to each parent. Logistic regression models were used to estimate odds ratios (OR) and 95% confidence intervals (CI). RESULTS: Maternal wood-related job was not associated with the risk of TGCT in offspring (OR 1.08, CI 0.55-2.14), while paternal wood-related job was associated with a decreased risk of TGCT in offspring (OR 0.85, CI 0.75-0.96). None of the specific wood-related jobs, such as upholsterers, sawyers, or construction carpenters, were significantly associated with a risk of TGCT. Only exception was observed in a sensitivity analysis which showed an increased risk in the small group of sons of fathers working as 'cabinetmakers and joiners' the year before conception (OR of 2.06, CI 1.00-4.25). CONCLUSION: This large-scale NORD-TEST analysis provided no evidence of an association between parental prenatal exposures in wood-related jobs and TGCT in sons.

Male fetus susceptibility to maternal inflammation: C-reactive protein and brain development.

BACKGROUND: Maternal inflammation in early pregnancy has been identified epidemiologically as a prenatal pathogenic factor for the offspring's later mental illness. Early newborn manifestations of the effects of maternal inflammation on human fetal brain development are largely unknown. METHODS: Maternal infection, depression, obesity, and other factors associated with inflammation were assessed at 16 weeks gestation, along with maternal C-reactive protein (CRP), cytokines, and serum choline. Cerebral inhibition was assessed by inhibitory P50 sensory gating at 1 month of age, and infant behavior was assessed by maternal ratings at 3 months of age. RESULTS: Maternal CRP diminished the development of cerebral inhibition in newborn males but paradoxically increased inhibition in females. Similar sex-dependent effects were seen in mothers' assessment of their infant's self-regulatory behaviors at 3 months of age. Higher maternal choline levels partly mitigated the effect of CRP in male offspring. CONCLUSIONS: The male fetal-placental unit appears to be more sensitive to maternal inflammation than females. Effects are particularly marked on cerebral inhibition. Deficits in cerebral inhibition 1 month after birth, similar to those observed in several mental illnesses, including schizophrenia, indicate fetal developmental pathways that may lead to later mental illness. Deficits in early infant behavior follow. Early intervention before birth, including prenatal vitamins, folate, and choline supplements, may help prevent fetal development of pathophysiological deficits that can have life-long consequences for mental health.

No evidence for a difference in 2D:4D ratio between youth with elevated prenatal androgen exposure due to congenital adrenal hyperplasia and controls.

The second-to-fourth digit ratio (2D:4D) has been associated with sexual dimorphism, with a lower 2D:4D in males. A large body of research has relied on the 2D:4D as a proxy for prenatal androgen exposure, and includes reports of relationships between 2D:4D and a wide range of human traits. Here, we examine the validity of the 2D:4D proxy by studying the association between 2D:4D and classical Congenital Adrenal Hyperplasia (CAH) due to 21-hydroxylase deficiency, a condition characterized by excessive prenatal exposure to androgens during most of the gestational period. To this end, we retrospectively examine 513 serial radiographs of the left hand obtained clinically in 90 youth with classical CAH (45 female) and 70 control youth (31 female). Replicating previous reports, we observe associations of the 2D:4D with sex (lower 2D:4D in males) and age (increase of 2D:4D through development). However, we find no evidence for differences in 2D:4D between CAH and controls (full sample: ß = -0.001 (-0.008, 0.006); females: ß = -0.004 [-0.015, 0.007]; males: ß = 0.001, [-0.008, 0.011]). Although our findings do not rule out a small association between the 2D:4D and CAH, they cast doubt on the usefulness of the 2D:4D as a biomarker for prenatal androgen exposure in behavioral research.

Gestational diabetes and childhood asthma in a racially diverse US pregnancy cohort.

BACKGROUND: Childhood asthma is a common chronic disease that likely has prenatal origins. Gestational diabetes alters maternal physiology and may influence fetal risk for childhood-onset disease. However, the association between gestational diabetes and child asthma is not well characterized. OBJECTIVE: To investigate the association between gestational diabetes and wheeze/asthma at approximately 4 years of age in a racially diverse US cohort. METHODS: We studied mother-child dyads enrolled prenatally in the Conditions Affecting Neurocognitive Development and Learning in Early Childhood study. Gestational diabetes was determined by medical chart review. At approximately 4 years of age, we assessed child respiratory outcomes including parent report of physician-diagnosed asthma (ever), current wheeze (symptoms within the past 12 months), and current asthma (physician diagnosis and/or medication or symptoms within the past 12 months). We used the modified Poisson regression to assess associations between gestational diabetes and child respiratory outcomes, adjusting for maternal age, race, prenatal smoking, pre-pregnancy body mass index, parity, asthma history, socioeconomic status, and infant sex. RESULTS: Among 1107 women, 66% were African American/Black. Six percent (n = 62) had gestational diabetes documented during pregnancy. Gestational diabetes was associated with increased risk of physician-diagnosed asthma (adjusted risk ratio (RR) [95% Confidence Interval]: 2.13 [1.35, 3.38]; prevalence: 14%), current wheeze (RR: 1.85 [1.23, 2.78]; prevalence: 19%), and current asthma (RR: 2.01 [1.30, 3.10]; prevalence: 16%). CONCLUSIONS: Gestational diabetes was associated with increased risk of asthma and wheeze outcomes. Additional studies are needed to elucidate modifiable pathways underlying this association.

Prenatal exposure to non-steroidal anti-inflammatory drugs and risk of attention-deficit/hyperactivity disorder: A follow-up study in the Norwegian mother, father and child cohort.

PURPOSE: To estimate the association between Attention-Deficit/Hyperactivity Disorder (ADHD) in children in preschool and primary school, and prenatal exposure to non-steroidal anti-inflammatory drugs (NSAIDs) by timing and duration. METHODS: This study was based on the Norwegian Mother, Father and Child Cohort Study linked to the Medical Birth Registry of Norway, the Norwegian Patient Registry (NPR) and the Norwegian Prescription Database (NorPD). NSAID exposure was identified by maternal self-report in pregnancy. Child diagnosis of ADHD was obtained from NPR and NorPD. Symptoms of ADHD at age 5 years were measured using Conners' Parent Rating Scale-Revised, where higher scores correspond to more symptoms. To account for time-varying exposure and confounders, marginal structural models were fitted to estimate hazard ratios and mean difference in z-scores. RESULTS: The analyses on ADHD diagnosis and ADHD symptoms included 56 340 and 34 961 children respectively. Children exposed to NSAIDs prenatally had no increased risk of ADHD diagnosis (first trimester: HR 1.12, 95% CI 0.86;1.45, second trimester: HR 0.98, 95% CI 0.69;1.38, third trimester: HR 0.68, 95% CI 0.31; 1.46) or ADHD symptoms (first trimester: standardized mean difference 0.03, 95% CI -0.03;0.09, second trimester: standardized mean difference 0.03, 95% CI -0.04;0.11, third trimester: standardized mean difference 0.11, 95% CI -0.03; 0.25). There was no duration-response relationship for either outcome. CONCLUSION: Though non-differential misclassification of the exposure may have attenuated results, these findings are reassuring and suggest no substantially increased risk of ADHD diagnosis or symptoms in children prenatally exposed to NSAIDs, regardless of timing or duration.

Early-life exposure to the Chinese famine of 1959-61 and risk of Hyperuricemia: results from the China health and retirement longitudinal study.

BACKGROUND: Short-term starvation has been related to hyperuricemia. However, little is known about the long-term effect of early-life exposure to famine on hyperuricemia risk in adulthood. METHODS: The analysis included 2383 participants from the China Health and Retirement Longitudinal Study in 2015. Hyperuricemia was diagnosed as serum uric acid ≥7 mg/dL in men and serum uric acid ≥6 mg/dL in women. Famine exposure subgroups were defined as unexposed (born between October 1, 1962, and September 30, 1964), fetal-exposed (born between October 1, 1959, and September 30, 1961), and early-childhood exposed (born between October 1, 1956, and September 1, 1958). The association between early-life famine exposure and hyperuricemia risk was assessed using multivariate logistic regression. RESULTS: The prevalence of hyperuricemia in the unexposed, fetal-exposed, and early-childhood exposed participants was 10.7, 14.1, 11.1%, respectively. Compared with unexposed and early-childhood exposed participants combined as an age-balanced control, fetal-exposed participants showed an increased risk of hyperuricemia in adulthood (OR = 1.41; 95% CI: 1.06-1.88), after adjusting for gender, marital status, famine severity, residence, smoking, drinking, BMI, hypertension, and diabetes. The famine effect on hyperuricemia was accentuated by overweight or obesity (P for interaction = 0.042). Compared with unexposed and BMI < 24 kg/m2 participants, the OR (95%CI) of hyperuricemia was 3.66 (2.13-6.30) for fetal-exposed and overweight/obesity participants. However, combined unexposed and early-childhood exposed participants as an age-balanced control, the interaction of famine exposure and BMI was not statistically significant (P for interaction = 0.054). CONCLUSION: Famine exposure in the fetal stage was associated with an increased risk of hyperuricemia in adulthood.

Maternal Mental Disorders before Delivery and the Risk of Dental Caries in Children.

Prevention of childhood caries is an ongoing public health challenge, but the possibility of an association with maternal mental disorders has received limited attention. We estimated the extent to which maternal mental disorders are associated with an increased risk of hospitalization due to dental caries. We conducted a longitudinal cohort study of 790,758 infants born in Quebec, Canada between 2006 and 2016, with follow-up extending to 2018. We identified women with mental disorders before or during pregnancy and computed the incidence of dental caries in their children. We estimated HR and 95% CI for the association of maternal mental disorders with the risk of dental caries, adjusted for personal characteristics. Infants of women with mental disorders before or during pregnancy had a higher incidence of dental caries compared to children of women with no mental disorder (56.1 vs. 27.2 per 10,000 person-years). Maternal stress and anxiety disorders (HR = 1.73; 95% CI 1.60-1.86), depression (HR = 1.81; 95% CI 1.60-2.03), schizophrenia and delusional disorders (HR = 1.69; 95% CI 1.29-2.22), and personality disorders (HR = 1.89; 95% CI 1.70-2.11) were associated with the risk of dental caries. The associations were present throughout childhood, including after 7 years (HR = 1.65; 95% CI 1.38-1.96). Maternal mental disorders were associated with caries of the enamel, dentin, and cementum and caries that reached the dental pulp. Maternal mental disorders before or during pregnancy, especially stress and anxiety, depression, schizophrenia, and personality disorders, are associated with the risk of childhood caries. Women with a history of mental disorders may benefit from enhanced strategies for prevention of dental caries in their children.

[Analysis of scoring system of twin pregnancy vaginal delivery].

Objective: To Analyze the prenatal factors and forecast the success rate of vaginal delivery of twin pregnancy. Methods: Totally, 114 cases of twin pregnant women who were under the systematic antenatal care and had deliveries in Beijing Obstetrics and Gynecology Hospital from January 2017 to March 2019 were collected. The inclusive criteria were uncomplicated twin pregnancy with head downward position of the first fetus, not monochorioallantoic twin twins, and the willingness for vaginal delivery. Two groups were classified based on their successful vaginal delivery. 96 cases in vaginal delivery group (study group) and 18 cases in the comparison groupwhich were transferred to Caesarean sections during trial delivery. The evaluated prenatal factors included: (1) Fetal factors: the chorionicity of the twin pregnancy, position of the second fetus, fetal weights and the weight difference of two fetuses. (2) Maternal factors:the maternal age, delivery gestational age, parity, body mass index (BMI), reasonability of weight gain during pregnancy, pregnancy complications, such as gestational diabetes mellitus (GDM), hypertensive disorder of pregnancy, and the application of assisted reproductive technology. (3) The technical title of the delivery doctor, modes of labour (spontaneous labor or induced labour and its mode) and the application of labor analgesia, etc. Single-factor logistic analysis and multiple-factor logistic regression were used to do statistical analysis and nomograms were plotted, finally receiver operating characteristic (ROC) curves and standard curves were formed for internal verifications and Youden index were utilized to determine the cut-off values. Results: Five variables:maternal age,complicated GDM, reasonability of weight gain during pregnancy, parity, and the weight of the second fetus is less than the firsthad obvious influence on the success rate of vaginal delivery in twin pregnancy. After quantifying the influence weight, the influence of each factor was as follows:the age of the mother <35 years old: 64; no GDM: 100, no insulin application in GDM: 47, and application of insulin: 0; reasonability of weight gain during pregnancy: 82; parity≥2: 58; and the weight of the second fetus was less than the first: 57. The ROC curve was plotted and the area under the curve (AUC) is 0.856 1, which were able to forecast the success rates well, the maximum value of the Youden index was 0.564 7 and the corresponding score was 168. Conclusions: maternal age, reasonability of weight gain during pregnancy, the complication of GDM, parity, and the weight of the second fetus less than the first are the influential prenatal factors on vaginal delivery of twin pregnancy. After assigning the influence weight of each influencing factor, when the total score reaches 168 the success rate of vaginal delivery is significantly improved.

Use of Negative Control Exposure Analysis to Evaluate Confounding: An Example of Acetaminophen Exposure and Attention-Deficit/Hyperactivity Disorder in Nurses' Health Study II.

Frequent maternal use of acetaminophen in pregnancy has been linked to attention-deficit/hyperactivity disorder (ADHD) in children, but concerns regarding uncontrolled confounding remain. In this article, we illustrate use of the negative control exposure (NCE) approach to evaluate uncontrolled confounding bias in observational studies on pregnancy drug safety and explain the causal assumptions behind the method. We conducted an NCE analysis and evaluated the associations between maternal acetaminophen use during different exposure periods and ADHD among 8,856 children born in 1993-2005 to women enrolled in the Nurses' Health Study II cohort. Information on regular maternal acetaminophen use was collected prospectively in biennial questionnaires. A total of 721 children (8.1%) in the cohort had been diagnosed with ADHD as reported by the mothers. Our NCE analysis suggested that only acetaminophen use at the time of pregnancy was associated with childhood ADHD (odds ratio = 1.34, 95% confidence interval: 1.05, 1.72), and the effect estimates for the 2 NCE periods (about 4 years before and 4 years after the pregnancy) were null. Our findings corroborate those of prior reports suggesting that prenatal acetaminophen exposure may influence neurodevelopment. The lack of an association between acetaminophen use in the pre- and postpregnancy exposure periods and ADHD provides assurance that uncontrolled time-invariant factors do not explain this association.

Parental time to pregnancy, medically assisted reproduction and pubertal development in boys and girls.

STUDY QUESTION: Does parental fertility, measured by time to pregnancy (TTP), or use of medically assisted reproduction (MAR) affect pubertal development in the offspring? SUMMARY ANSWER: Neither TTP nor type of MAR treatment had clinically relevant implications for mean age at achieving individual pubertal milestones or overall timing of puberty in boys and girls. WHAT IS KNOWN ALREADY: Parental TTP and MAR have been associated with impaired semen quality in adult sons. Timing of puberty reflects earlier signals of reproductive health, but it remains unclear whether parental fertility or MAR affects pubertal development, especially in the growing generation of children conceived by IVF or ICSI. STUDY DESIGN, SIZE, DURATION: In this study, 15 819 children born by mothers in the Danish National Birth Cohort from 2000 to 2003 participated in a nationwide puberty cohort (participation rate = 70%). Parental TTP and use of MAR were reported by mothers in early pregnancy and children's pubertal development data was self-recorded in web-based questionnaires from 11 years of age and 6 monthly throughout puberty (2012-2018). PARTICIPANTS/MATERIALS, SETTING, METHODS: Pubertal development in children (of planned pregnancies, n = 13 285) born by untreated subfecund (TTP: 6-12 months) (n =2038), untreated severely subfeund (TTP: >12 months) (n = 1242), treated subfecund (n = 230) and treated severely subfecund (n = 1234) parents were compared to children born to more fertile parents (TTP: ≤5 months). We estimated mean monthly differences in mean age at achieving individual pubertal milestones (i.e. age at menarche, voice break, first ejaculation and Tanner stages 2, 3, 4 and 5 for breast or genital development and pubic hair growth) and a combined indicator of timing of puberty. Further, we compared mean age at achieving the individual pubertal milestones in children born by use of IVF or ICSI (n = 480) with children born by controlled ovarian stimulation or ovulation induction with or without intrauterine insemination (n = 902). MAIN RESULTS AND THE ROLE OF CHANCE: We found tendencies towards slightly later mean age at male pubertal timing and slightly earlier mean age at female pubertal timing among children born by untreated subfecund, treated subfecund, untreated severely subfecund and treated severely subfecund parents. There were no specific patterns with increasing TTP, use of MAR nor type of MAR treatment, and the magnitude of the mean differences for individual milestones and overall timing of puberty were small, i.e. 0.9 months (95% CI: -1.0; 2.8) for first ejaculation and -0.5 months (95% CI: -2.0; 1.0) months for age at menarche in boys and girls, respectively, born by treated severely subfecund parents when compared with children born by more fertile parents. LIMITATIONS, REASONS FOR CAUTION: Non-differential misclassification of the self-reported information on parental TTP and pubertal development in the offspring may serve as an alternative explanation of the findings, possibly biasing the estimates towards the null. The information on pubertal development was collected from around 11 years of age and onwards. WIDER IMPLICATIONS OF THE FINDINGS: This study adds to the growing body of literature suggesting only limited harmful effects of parental subfecundity and MAR on offspring's long-term growth and development. STUDY FUNDING/COMPETING INTEREST(S): This work was supported by the Danish Council for Independent Research [DFF 4183-00152]; and the Faculty of Health at Aarhus University. The authors have no financial relationships or competing interests to disclose.

In utero exposure to selective serotonin reuptake inhibitors and development of mental disorders: a systematic review and meta-analysis.

OBJECTIVE: Several studies have investigated whether in utero exposure to selective serotonin reuptake inhibitors (SSRIs) is associated with increased risk of developing mental or behavioural disorders. The aim of this study was to perform a systematic review and meta-analysis based on this literature. METHODS: A systematic search of eligible literature in PubMed, EMBASE, and PsycINFO and subsequent meta-analysis was conducted in adherence with the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guideline. RESULTS: A total of 20 studies were included in the review, and results from 18 of these were meta-analyzed. We found a statistically significant positive association between in utero exposure to SSRIs and mental or behavioural disorders such as autism spectrum disorder (hazard ratio (HR) = 1.27; 95% confidence interval (CI) = 1.10-1.47), attention-deficit/hyperactivity disorder (HR = 1.33; 95% CI = 1.06-1.66) and mental retardation (HR = 1.41; 95% CI = 1.03-1.91). Confounding by indication was identified in five of seven studies investigating this aspect. CONCLUSION: Exposure to SSRIs in utero is associated with increased risk of developing mental or behavioural disorders. However, these associations do not necessarily reflect a causal relationship since the results included in this meta-analysis are likely affected by residual confounding by indication, which is likely to account for some (or all) of the positive association.

Prenatal exposure to non-steroidal anti-inflammatory drugs (NSAIDs) and neurodevelopmental outcomes in children.

PURPOSE: Non-steroidal anti-inflammatory drugs (NSAIDs) are commonly used during pregnancy. Findings that prenatal NSAID exposure may affect offspring neurodevelopment have been inconsistent. We investigated the effect of prenatal NSAID exposure on childhood neurodevelopment and explored the susceptibility of our effect estimates to forms of bias via negative exposure, negative outcome, and multi-informant analyses. METHODS: In a cohort of pregnant women (n = 6876), perinatal NSAID use was assessed by prescriptions and self-report. Primary neurodevelopmental outcomes included attention problems using maternal reports at 1½, 3, and 5 years. To explore potential systematic biases, we compared estimates from maternally reported attention problems to a teacher's report and a measure of nonverbal intelligence assessed at a clinic visit at age 6 years; we also used NSAID use before pregnancy and somatic problems as a "negative" exposure and outcome, respectively. RESULTS: Maternal reports suggested that prenatal exposure to NSAIDs was associated with more attention problems at younger ages (eg, at age 3: mean difference in attention problems score: 0.30; 95% CI 0.12, 0.48). However, no strong association with attention problems was found in the teacher report, and a similarly strong association between prenatal NSAID exposure and somatic complaints suggests residual confounding by indication likely remains. Moreover, prenatal exposure to NSAIDs was not associated with an observed measure of IQ (mean difference in IQ score: -0.32; 95% CI: -1.82, 1.19). CONCLUSIONS: Jointly, our results suggest that the observed associations between prenatal exposure to NSAIDs and child attention problems reflect systematic biases of a null or small effect.

Residential exposure to electromagnetic fields during pregnancy and risk of child cancer: A longitudinal cohort study.

OBJECTIVE: We assessed whether exposure to electromagnetic fields during pregnancy increases the risk of childhood cancer. METHODS: We studied a retrospective cohort of 784,944 newborns in Quebec, Canada between 2006 and 2016 who were followed for cancer one decade after birth. The exposures were residential distance to the nearest high voltage power transformer station and transmission line. We determined the incidence of childhood cancer, and estimated hazard ratios and 95% confidence intervals (CI) in Cox proportional hazards regression models adjusted for maternal and birth characteristics. RESULTS: There were 1114 incident cases of cancer during 4,647,472 person-years of follow-up. Residential proximity to transformer stations was associated with a somewhat greater risk of cancer, but there was no association with transmission lines. Compared with 200 m, a distance of 80 m from a transformer station was associated with a hazard ratio of 1.08 (95% CI 0.98, 1.20) for any cancer, 1.04 (95% CI 0.88, 1.23) for hematopoietic cancer, and 1.11 (95% CI 0.99, 1.25) for solid tumours. CONCLUSIONS: Residential proximity to transformer stations is associated with a borderline risk of childhood cancer, but the absence of an association with transmission lines suggests no causal link.

Prenatal selenium status, neonatal cerebellum measures and child neurodevelopment at the age of 18 months.

OBJECTIVES: The aim of this study was to evaluate the association of maternal blood selenium (Se) levels and cord blood Se levels with neonatal cerebellum measures and child neurodevelopment at the age of 18 months. Moreover, to investigate whether the neonatal cerebellum measures could be used as a potential biomarker for selenium homeostasis during pregnancy. STUDY GROUP AND METHODS: The study population consisted of 205 mother-child pairs from Croatian Mother and Child Cohort. Maternal blood and cord blood were obtained at delivery and selenium level was analyzed by Inductively Coupled Plasma Mass Spectrometry. Cranial ultrasonography examination was performed on 49 newborns - cerebellum length and width have been measured. Neurodevelopmental assessment of cognitive, language and motor skills were conducted on 154 children, using The Bayley Scales of Infant and Toddler Development, Third Edition (BSID-III), at the age of 18 months. RESULTS: The mean levels of selenium in maternal blood and cord blood were 92.6 ng/g and 97.0 ng/g, respectively. Maternal blood selenium levels were moderately and negatively correlated (r = -0.372; p = 0.008) with cerebellum length, while cord blood selenium levels were positively correlated with cerebellum width (r = 0.613; p = 0.007) among female children group. Maternal blood selenium levels were weakly and positively correlated (r = 0.176; p = 0.029) with child's cognitive abilities. CONCLUSION: To the best of our knowledge, our study is the first one investigating the association between neonatal brain measures and selenium levels in mother-child pairs. Our results indicate that prenatal selenium intake correlated with cerebellum length and width measured by cranial ultrasonography. Hence, cerebellum may be used as a potential biomarker and a target "organ" for early detection of possible adverse effects of prenatal status to various micronutrients.