Maternal caffeine intake during pregnancy is associated with risk of low birth weight: a systematic review and dose-response meta-analysis

Maternal caffeine, coffee and cola drink intake and the risk of gestational diabetes - Kuopio Birth Cohort

AIMS

Coffee intake is associated with a decreased risk of type 2 diabetes among non-pregnant people. We aimed to investigate the association between caffeine, coffee and cola drink intake in early pregnancy and the risk of gestational diabetes (GDM).

METHODS

Kuopio Birth Cohort (KuBiCo) is a prospective cohort study including pregnant women who were followed at the prenatal clinics in outpatient healthcare centers and gave birth in Kuopio University Hospital, Finland (n=2214). Maternal diet during the first trimester of pregnancy was assessed using a 160-item food frequency questionnaire. GDM was diagnosed by oral glucose tolerance test according to the Finnish national guidelines mainly between 24 and 28 gestational weeks.

RESULTS

Women with moderate coffee intake in the first trimester were less likely diagnosed with GDM than women without coffee intake in an age-adjusted model (OR 0.87; 95% CI 0.76-0.99; p = 0.03), but the association was attenuated in multi-adjusted models (p = 0.11). No association was found between caffeine intake and GDM. One third (32.4%) of pregnant women consumed caffeine over the recommendation (> 200 mg/d). Women who consumed cola drinks more than the median (33.3 mL/d) had an increased risk of GDM (OR 1.29; 95% CI 1.02-1.63, p = 0.037) in multi-adjusted model compared to those who consumed less.

CONCLUSIONS

Caffeine intake during the first trimester of pregnancy was not associated with the risk of GDM but a minor non-significant decrease was seen with moderate coffee intake. Although the average consumption of cola drinks was low in the KuBiCo cohort, higher consumption was associated with an increased risk of GDM. Further studies are needed to evaluate the safe amount of coffee during pregnancy, since the recommended caffeine intake was exceeded in almost half of the coffee drinkers.

The neuroprotective effect of exogen melatonin upon fetal hippocampus damage caused by high-dose caffeine administration in pregnant rats

OBJECTIVE

The aim of this study is to evaluate whether exogenous melatonin (MEL) mitigates the deleterious effects of high-dose caffeine (CAF) administration in pregnant rats upon the fetal hippocampus.

MATERIALS AND METHODS

A total of 32 adult Wistar albino female rats were divided into four groups after conception (n = 8). At 9-20 days of pregnancy, intraperitoneal (i.p.) MEL was administered at a dose of 10 mg/kg/day in the MEL group, while i.p. CAF was administered at a dose of 60 mg/kg/day in the CAF group. In the CAF plus MEL group, i.p. CAF and MEL were administered at a dose of 60 and 10 mg/kg/day, respectively, at the same period. Following extraction of the brains of the fetuses sacrificed on the 21st day of pregnancy, their hippocampal regions were analyzed by hematoxylin and eosin and Cresyl Echt Violet, anti-GFAP, and antisynaptophysin staining methods.

RESULTS

While there was a decrease in fetal and brain weights in the CAF group, it was found that the CAF plus MEL group had a closer weight average to that of the control group. Histologically, it was observed that the pyramidal cell layer consisted of 8-10 layers of cells due to the delay in migration in hippocampal neurons in the CAF group, while the MEL group showed similar characteristics with the control group. It was found that these findings decreased in the CAF plus MEL group.

CONCLUSION

It is concluded that high-dose CAF administration causes a delay in neurogenesis of the fetal hippocampus, and exogenous MEL is able to mitigate its deleterious effects.

The maternal factors associated with infant low birth weight: an umbrella review

BACKGROUND

In this umbrella review, we systematically evaluated the evidence from meta-analyses and systematic reviews of maternal factors associated with low birth weight.

METHODS

PubMed, Scopus, and Web of Science were searched to identify all relevant published studies up to August 2023. We included all meta-analysis studies (based on cohort, case-control, cross-sectional studies) that examined the association between maternal factors (15 risk factors) and risk of LBW, regardless of publication date. A random-effects meta-analysis was conducted to estimate the summary effect size along with the 95% confidence interval (CI), 95% prediction interval, and heterogeneity (I2) in all meta-analyses. Hedges' g was used as the effect size metric. The effects of small studies and excess significance biases were assessed using funnel plots and the Egger's test, respectively. The methodological quality of the included studies was assessed using the AMSTAR 2 tool.

RESULTS

We included 13 systematic Review with 15 meta-analysis studies in our study based on the inclusion criteria. The following 13 maternal factors were identified as risk factors for low birth weight: crack/cocaine (odds ratio [OR] 2.82, 95% confidence interval [CI] 2.26-3.52), infertility (OR 1.34, 95% CI 1.2-1.48), smoking (OR 2.00, 95% CI 1.76-2.28), periodontal disease (OR 2.41, 95% CI 1.67-3.47), depression (OR 1.84, 95% CI 1.34-2.53), anemia (OR 1.32, 95% CI 1.13-1.55), caffeine/coffee (OR 1.34, 95% CI 1.14-1.57), heavy physical workload (OR 1.87, 95% CI 1.00-3.47), lifting ≥ 11 kg (OR 1.59, 95% CI 1.02-2.48), underweight (OR 1.79, 95% CI 1.20-2.67), alcohol (OR 1.23, 95% CI 1.04-1.46), hypertension (OR 3.90, 95% CI 2.73-5.58), and hypothyroidism (OR 1.40, 95% CI 1.01-1.94). A significant negative association was also reported between antenatal care and low birth weight.

CONCLUSIONS

This umbrella review identified drug use (such as crack/cocaine), infertility, smoking, periodontal disease, depression, caffeine and anemia as risk factors for low birth weight in pregnant women. These findings suggest that pregnant women can reduce the risk of low birth weight by maintaining good oral health, eating a healthy diet, managing stress and mental health, and avoiding smoking and drug use.

Can mothers consume caffeine? The issue of early life exposure and metabolic changes in offspring

Caffeine is a substance with central and metabolic effects. Although it is recommended that its use be limited during pregnancy, many women continue to consume caffeine. Direct and indirect actions of caffeine in fetuses and newborns promote adaptive changes, according to the Developmental Origins of Health and Diseases (DOHaD) concept. In fact, epidemiological and experimental evidence reveals the impact of early caffeine exposure. Here, we reviewed these findings with an emphasis on experimental models with rodents. The similarity of human and rodent caffeine metabolism allows the comprehension of molecular mechanisms affected by prenatal caffeine exposure. Maternal caffeine intake affects the body weight and endocrine system of offspring at birth and has long-term effects on the endocrine system, liver function, glucose and lipid metabolism, the cardiac system, the reproductive system, and behavior. Interestingly, some of these effects are sex dependent. Thus, the dose of caffeine considered safe for pregnant women may not be adequate for the prenatal period.

Impairment of adenosine signaling disrupts early embryo development: unveiling the underlying mechanisms

Purinergic signaling has been implicated in many biological functions, including development. In this study, we investigate the functions of extracellular adenosine and adenosine receptors using a mouse embryonic stem cell (ESC) line and morula stages isolated from mouse embryos. Feeder-free mouse ESC was investigated in the absence and presence of the leukemia inhibitory factor (LIF), configuring undifferentiated cells and cells undergoing spontaneous differentiation. High alkaline phosphatase (ALPL) and low CD73 levels resulting in low adenosine (eADO) levels were characteristic for pluripotent cells in the presence of the LIF, while LIF deprivation resulted in augmented adenosine levels and reduced pluripotency marker expression, which indicated differentiation. Tracing ESC proliferation by BrdU labeling revealed that the inhibition of ALPL by levamisole resulted in a decrease in proliferation due to less eADO accumulation. Furthermore, caffeine and levamisole treatment, inhibiting adenosine receptor and eADO accumulation, respectively, reduced ESC migration, similar to that observed in the absence of the LIF. Pharmacological approaches of selective adenosine receptor subtype inhibition triggered specific adenosine receptor activities, thus triggering calcium or MAP kinase pathways leading to differentiation. In line with the in vitro data, mouse embryos at the morula stage were sensitive to treatments with A1 and A3 receptor antagonists, leading to the conclusion that A1 receptor and A3 receptor inhibition impairs proliferation and self-renewal and triggers inappropriate differentiation, respectively. The findings herein define the functions of eADO signaling in early development with implications for developmental disorders, in which adenosine receptors or ectonucleotidase dysfunctions are involved, and which could lead to malformations and miscarriages, due to exposure to caffeine.

Evidence for ethnicity and location as regulators of the newborn blood metabolome: a monozygous twin study

Introduction

Monochorionic, diamniotic (MCDA) monozygotic twins share nearly all genetic variation and a common placenta in utero. Despite this, MCDA twins are often discordant for a range of common phenotypes, including early growth and birth weight. As such, MCDA twins represent a unique model to explore variation in early growth attributable primarily to in utero environmental factors.

Methods

MCDA twins with a range of within-pair birth weight discordance were sampled from the peri/postnatal epigenetic twin study (PETS, Melbourne; n = 26 pairs), Beijing twin study (BTS, Beijing; n = 25), and the Chongqing longitudinal twin study (LoTiS, Chongqing; n = 22). All PETS participants were of European-Australian ancestry, while all Chinese participants had Han ancestry. The average of the birth weight difference between the larger and smaller co-twins for all twin pairs was determined and metabolomic profiles of amino acids, TCA cycle intermediates, fatty acids, organic acids, and their derivatives generated from cord blood plasma by gas chromatograph mass spectrometry. Within and between co-twin pair analyses were performed to identify metabolites specifically associated with discordance in birth weight. Multivariable regression and pathway enrichment analyses between different regions were performed to evaluate the geographical effects on the metabolism of MCDA twin pairs.

Results

PETS twins showed a markedly different metabolic profile at birth compared to the two Chinese samples. Within-pair analysis revealed an association of glutathione, creatinine, and levulinic acid with birth weight discordance. Caffeine, phenylalanine, and several saturated fatty acid levels were uniquely elevated in PETS twins and were associated with maternal BMI and average within pair birth weight, in addition to birth weight discordance. LoTiS twins had higher levels of glutathione, tyrosine, and gamma-linolenic acid relative to PETS and BTS twins, potentially associated with eating habits.

Conclusion

This study highlights the potential role of underlying genetic variation (shared by MZ twins), in utero (non-shared by MZ twins) and location-specific (shared by MZ twins) environmental factors, in regulating the cord blood metabolome of uncomplicated MCDA twins. Future research is needed to unravel these complex relationships that may play a key role in phenotypic metabolic alterations of twins independent of genetic diversity.

Caffeine intake during pregnancy and adverse outcomes: An integrative review

Caffeine intake during pregnancy is common. Caffeine crosses the placenta, raising concerns about its possible deleterious effects on the developing embryo/fetus. Studies on this subject show conflicting results, and still there is no consensus on the recommended dose of caffeine during pregnancy. We performed an integrative review with studies from six databases, using broad MESH terms to allow the identification of publications that addressed the outcomes of caffeine use during pregnancy, with no date limit for publications, in English and Portuguese language. The research returned 16,192 articles. After removing duplicates, screening by title, abstract and full-text, we evaluated 257 and included 59 articles. We found association between caffeine intake and pregnancy loss, low birth weight, cardiac and genital anomalies, higher body mass, and neurodevelopmental and neurobehavioral outcomes. The effects were often dose dependent. No association with prematurity has been demonstrated, but one study showed a small reduction in gestational age with increasing doses of caffeine intake. Defining a safe dose for caffeine intake during pregnancy is a challenging task due to the heterogeneity in study designs and results, as well as the difficulty of reliably assessing the amount of caffeine consumed. In some studies, exposures below the recommended level of caffeine intake during pregnancy (200 mg/day), as suggested by the guidelines, were associated with pregnancy loss, low birth weight, cardiac and genital anomalies, higher body mass, and neurodevelopmental and neurobehavioral outcomes. Well-designed studies with reliable quantification of caffeine intake are needed to assess the safety of low doses during pregnancy.

Prenatal caffeine exposure induces autism-like behaviors in offspring under a high-fat diet via the gut microbiota-IL-17A-brain axis

Prenatal caffeine exposure (PCE) is a significant contributor to intrauterine growth retardation (IUGR) in offspring, which has been linked to an increased susceptibility to autism spectrum disorder (ASD) later in life. Additionally, a high-fat diet (HFD) has been shown to exacerbate ASD-like behaviors, but the underlying mechanisms remain unclear. In this study, we first noted in the rat model of IUGR induced by PCE that male PCE offspring exhibited typical ASD-like behaviors post-birth, in contrast to their female counterparts. The female PCE offspring demonstrated only reduced abilities in free exploration and spatial memory. Importantly, both male and female PCE offspring displayed ASD-like behaviors when exposed to HFD. We further observed that PCE + HFD offspring exhibited damaged intestinal mucus barriers and disturbed gut microbiota, resulting in an increased abundance of Escherichia coli (E. coli). The induced differentiation of colonic Th17 cells by E. coli led to an increased secretion of IL-17A, which entered the hippocampus through peripheral circulation and caused synaptic damage in hippocampal neurons, ultimately resulting in ASD development. Our strain transplantation experiment suggested that E. coli-mediated increase of IL-17A may be the core mechanism of ASD with a fetal origin. In conclusion, PCE and HFD are potential risk factors for ASD, and E. coli-mediated IL-17A may play a crucial role in fetal-originated ASD through the gut-brain axis.

Objective measures of smoking and caffeine intake and the risk of adverse pregnancy outcomes

BACKGROUND

In pregnancy, women are encouraged to cease smoking and limit caffeine intake. We employed objective definitions of smoking and caffeine exposure to assess their association with adverse outcomes.

METHODS

We conducted a case cohort study within the Pregnancy Outcome Prediction study to analyse maternal serum metabolomics in samples from 12, 20, 28 and 36 weeks of gestational age. Objective smoking status was defined based on detectable cotinine levels at each time point and objective caffeine exposure was based on tertiles of paraxanthine levels at each time point. We used logistic and linear regression to examine the association between cotinine, paraxanthine and the risk of pre-eclampsia, spontaneous pre-term birth (sPTB), fetal growth restriction (FGR), gestational diabetes mellitus and birthweight.

RESULTS

There were 914 and 915 women in the smoking and caffeine analyses, respectively. Compared with no exposure to smoking, consistent exposure to smoking was associated with an increased risk of sPTB [adjusted odds ratio (aOR) = 2.58, 95% CI: 1.14 to 5.85)] and FGR (aOR = 4.07, 95% CI: 2.14 to 7.74) and lower birthweight (β = -387 g, 95% CI: -622 g to -153 g). On univariate analysis, consistently high levels of paraxanthine were associated with an increased risk of FGR but that association attenuated when adjusting for maternal characteristics and objective-but not self-reported-smoking status.

CONCLUSIONS

Based on objective data, consistent exposure to smoking throughout pregnancy was strongly associated with sPTB and FGR. High levels of paraxanthine were not independently associated with any of the studied outcomes and were confounded by smoking.

Current therapeutic targets and multifaceted physiological impacts of caffeine

Caffeine, which shares consubstantial structural similarity with purine adenosine, has been demonstrated as a nonselective adenosine receptor antagonist for eliciting most of the biological functions at physiologically relevant dosages. Accumulating evidence supports caffeine's beneficial effects against different disorders, such as total cardiovascular diseases and type 2 diabetes. Conversely, paradoxical effects are also linked to caffeine ingestion in humans including hypertension-hypotension and tachycardia-bradycardia. These observations suggest the association of caffeine action with its ingested concentration and/or concurrent interaction with preferential molecular targets to direct explicit events in the human body. Thus, a coherent analysis of the functional targets of caffeine, relevant to normal physiology, and disease pathophysiology, is required to understand the pharmacology of caffeine. This review provides a broad overview of the experimentally validated targets of caffeine, particularly those of therapeutic interest, and the impacts of caffeine on organ-specific physiology and pathophysiology. Overall, the available empirical and epidemiological evidence supports the dose-dependent functional activities of caffeine and advocates for further studies to get insights into the caffeine-induced changes under specific conditions, such as asthma, DNA repair, and cancer, in view of its therapeutic applications.

Microbiota-indole 3-propionic acid-brain axis mediates abnormal synaptic pruning of hippocampal microglia and susceptibility to ASD in IUGR offspring

BACKGROUND

Autism spectrum disorder (ASD) has been associated with intrauterine growth restriction (IUGR), but the underlying mechanisms are unclear.

RESULTS

We found that the IUGR rat model induced by prenatal caffeine exposure (PCE) showed ASD-like symptoms, accompanied by altered gut microbiota and reduced production of indole 3-propionic acid (IPA), a microbiota-specific metabolite and a ligand of aryl hydrocarbon receptor (AHR). IUGR children also had a reduced serum IPA level consistent with the animal model. We demonstrated that the dysregulated IPA/AHR/NF-κB signaling caused by disturbed gut microbiota mediated the hippocampal microglia hyperactivation and neuronal synapse over-pruning in the PCE-induced IUGR rats. Moreover, postnatal IPA supplementation restored the ASD-like symptoms and the underlying hippocampal lesions in the IUGR rats.

CONCLUSIONS

This study suggests that the microbiota-IPA-brain axis regulates ASD susceptibility in PCE-induced IUGR offspring, and supplementation of microbiota-derived IPA might be a promising interventional strategy for ASD with a fetal origin. Video Abstract.

Maternal caffeine consumption during pregnancy and offspring cord blood DNA methylation: an epigenome-wide association study meta-analysis

Background: Prenatal caffeine exposure may influence offspring health via DNA methylation, but no large studies have tested this. Materials & methods: Epigenome-wide association studies and differentially methylated regions in cord blood (450k or EPIC Illumina arrays) were meta-analyzed across six European cohorts (n = 3725). Differential methylation related to self-reported caffeine intake (mg/day) from coffee, tea and cola was compared with assess whether caffeine is driving effects. Results: One CpG site (cg19370043, PRRX1) was associated with caffeine and another (cg14591243, STAG1) with cola intake. A total of 12-22 differentially methylated regions were detected with limited overlap across caffeinated beverages. Conclusion: We found little evidence to support an intrauterine effect of caffeine on offspring DNA methylation. Statistical power limitations may have impacted our findings.

Assessment of caffeine intake in groups of pregnant and breastfeeding women: A cross-sectional analysis

BACKGROUND & AIMS

Caffeine is commonly consumed by pregnant and breastfeeding women. The maximum safe dose of caffeine in their diet is 200 mg per day, according to the European Food Safety Authority. The purpose of this study was to assess the consumption of caffeinated products by pregnant and breastfeeding women, as well as to estimate their caffeine intake.

METHODS

The number of subjects who qualified for the study was 1112 women, of whom 401 were pregnant and 711 were breastfeeding. The research was conducted with the use of a questionnaire, which included information about food frequency and history of consumption of caffeinated products during the past 3 days.

RESULTS

The median (interquartile range) daily caffeine intake among pregnant women was 114.5 (57.6-202.8) mg, and the level of caffeine intake increased with the duration of pregnancy (p < 0.001). For breastfeeding women it was 193.7 (100.5-324.8) mg/d. The majority of participants (58.9%) were not able to correctly identify the safe amount of caffeine in their diets. It was observed that the intake of 73.8% of pregnant women and 51.9% of breastfeeding women fit within the safe range (0-200 mg/d). The main sources of caffeine were ground coffee, black tea, and instant coffee. For 63,6% of women knowledge about nutrition and supplementation came most often from blogs and social media run by medical professionals. Pleasure was the main reason for drinking coffee and tea.

CONCLUSION

Most pregnant women did not exceed the recommended maximum daily dose of caffeine, while breastfeeding women often did.

Genotoxic effects of caffeine in female mice exposed during pregnancy and lactation period and their offspring

Caffeine is a widely consumed substance, and there is a discussion about its effects when ingested by women during pregnancy and lactation. We aimed to identify the genotoxic effects of caffeine in female mice that consumed it during pregnancy and lactation periods and its consequences in their offspring. Thirty-six couples of Swiss mice received water or caffeine (0.3 and 1.0 mg/mL) treatment during pregnancy and lactation. The male and female offspring were divided into 12 groups according to the treatment administered to the female mice. Genotoxicity was assessed using the comet assay and the micronucleus test. Both doses of caffeine showed genotoxic effects in pregnant and lactating mice groups compared to groups not administered caffeine. In relation to offspring, it can be observed that females and males of the offspring had low weight in early life. In both female and male offspring, genotoxicity was detected in the blood, liver, and kidney tissues. Thus, from the present study, we can suggest that the caffeine consumed by female mice during the periods of pregnancy and lactation led to genotoxic effects in their offspring.

The adenosine hypothesis of schizophrenia into its third decade: From neurochemical imbalance to early life etiological risks

The adenosine hypothesis of schizophrenia was conceptualized about two decades ago in an attempt to integrate two prominent theories of neurochemical imbalance that attribute the pathogenesis of schizophrenia to hyperfunction of the mesocorticolimbic dopamine neurotransmission and hypofunction of cortical glutamate neurotransmission. Given its unique position as an endogenous modulator of both dopamine and glutamate signaling in the brain, adenosine was postulated as a potential new drug target to achieve multiple antipsychotic actions. This new strategy may offer hope for improving treatment, especially in alleviating negative symptoms and cognitive deficits of schizophrenia that do not respond to current medications. To date, however, the adenosine hypothesis has yet led to any significant therapeutic breakthroughs. Here, we address two possible reasons for the impasse. First, neither the presence of adenosine functional deficiency in people with schizophrenia nor its causal relationship to symptom production has been satisfactorily examined. Second, the lack of novel adenosine-based drugs also impedes progress. This review updates the latest preclinical and clinical data pertinent to the construct validity of the adenosine hypothesis and explores novel molecular processes whereby dysregulation of adenosine signaling could be linked to the etiology of schizophrenia. It is intended to stimulate and revitalize research into the adenosine hypothesis towards the development of a new and improved generation of antipsychotic drugs that has eluded us for decades.

Mendelian randomization study of maternal coffee consumption and its influence on birthweight, stillbirth, miscarriage, gestational age and pre-term birth

BACKGROUND

Coffee consumption has been associated with several adverse pregnancy outcomes, although data from randomized-controlled trials are lacking. We investigate whether there is a causal relationship between coffee consumption and miscarriage, stillbirth, birthweight, gestational age and pre-term birth using Mendelian randomization (MR).

METHODS

A two-sample MR study was performed using summary results data from a genome-wide association meta-analysis of coffee consumption (N = 91 462) from the Coffee and Caffeine Genetics Consortium. Outcomes included self-reported miscarriage (N = 49 996 cases and 174 109 controls from a large meta-analysis); the number of stillbirths [N = 60 453 from UK Biobank (UKBB)]; gestational age and pre-term birth (N = 43 568 from the 23andMe, Inc cohort) and birthweight (N = 297 356 reporting own birthweight and N = 210 248 reporting offspring's birthweight from UKBB and the Early Growth Genetics Consortium). Additionally, a one-sample genetic risk score (GRS) analysis of coffee consumption in UKBB women (N up to 194 196) and the Avon Longitudinal Study of Parents and Children (N up to 6845 mothers and 4510 children) and its relationship with offspring outcomes was performed.

RESULTS

Both the two-sample MR and one-sample GRS analyses showed no change in risk of sporadic miscarriages, stillbirths, pre-term birth or effect on gestational age connected to coffee consumption. Although both analyses showed an association between increased coffee consumption and higher birthweight, the magnitude of the effect was inconsistent.

CONCLUSION

Our results suggest that coffee consumption during pregnancy might not itself contribute to adverse outcomes such as stillbirth, sporadic miscarriages and pre-term birth or lower gestational age or birthweight of the offspring.

Diet-associated vertically transferred metabolites and risk of asthma, allergy, eczema, and infections in early childhood

BACKGROUND

Evidence suggests maternal pregnancy dietary intake and nutrition in the early postnatal period to be of importance for the newborn child's health. However, studies investigating diet-related metabolites transferred from mother to child on disease risk in childhood are lacking. We sought to investigate the influence of vertically transferred metabolites on risk of atopic diseases and infections during preschool age.

METHODS

In the Danish population-based COPSAC2010 mother-child cohort, information on 10 diet-related vertically transferred metabolites from metabolomics profiles of dried blood spots (DBS) at age 2-3 days was analyzed in relation to the risk of childhood asthma, allergy, eczema, and infections using principal component and single metabolite analyses.

RESULTS

In 678 children with DBS measurements, a coffee-related metabolite profile reflected by principal component 1 was inversely associated with risk of asthma (odds ratio (95% CI) 0.78 (0.64; 0.95), p = .014) and eczema at age 6 years (0.79 (0.65; 0.97), p = .022). Furthermore, increasing stachydrine (fruit-related), 3-carboxy-4-methyl-5-propyl-2-furanpropanoate (fish-related), and ergothioneine (fruit-, green vegetables-, and fish-related) levels were all significantly associated with reduced risks of infections at age 0-3 years (p < .05).

CONCLUSION

This study demonstrates associations between pregnancy diet-related vertically transferred metabolites measured in children in early life and risk of atopic diseases and infections in childhood. The specific metabolites associated with a reduced disease risk in children may contribute to the characterization of a healthy nutritional profile in pregnancy using a metabolomics-based unbiased tool for predicting childhood health.

Maternal Iodine Status and Birth Outcomes: A Systematic Literature Review and Meta-Analysis

Background & aims: Iodine is important for thyroid function during pregnancy to support fetal growth, but studies of maternal iodine status and birth outcomes are conflicting. We aimed to quantify the association between iodine status and birth outcomes, including potential threshold effects using nonlinear dose−response curves. Methods: We systematically searched Medline and Embase to 10 October 2022 for relevant cohort studies. We conducted random-effects meta-analyses of urinary iodine concentration (UIC), iodine:creatinine ratio (I:Cr), and iodide intake for associations with birth weight, birth weight centile, small for gestational age (SGA), preterm delivery, and other birth outcomes. Study quality was assessed using the Newcastle-Ottawa scale. Results: Meta-analyses were conducted on 23 cohorts with 42269 participants. Birth weight was similar between UIC ≥ 150 μg/L and <150 μg/L (difference = 30 g, 95% CI −22 to 83, p = 0.3, n = 13, I2 = 89%) with no evidence of linear trend (4 g per 50 μg/L, −3 to 10, p = 0.2, n = 12, I2 = 80%). I:Cr was similar, but with nonlinear trend suggesting I:Cr up to 200 μg/g associated with increasing birthweight (p = 0.02, n = 5). Birthweight was 2.0 centiles (0.3 to 3.7, p = 0.02, n = 4, I2 = 0%) higher with UIC ≥ 150 μg/g, but not for I:Cr. UIC ≥ 150 μg/L was associated with lower risk of SGA (RR = 0.85, 0.75 to 0.96, p = 0.01, n = 13, I2 = 0%), but not with I:Cr. Conclusions: The main risk of bias was adjustment for confounding, with variation in urine sample collection and exposure definition. There were modest-sized associations between some measures of iodine status, birth weight, birth weight centile, and SGA. In pregnancy, we recommend that future studies report standardised measures of birth weight that take account of gestational age, such as birth weight centile and SGA. Whilst associations were modest-sized, we recommend maintaining iodine sufficiency in the population, especially for women of childbearing age on restricted diets low in iodide.

Association of Maternal Caffeine Consumption During Pregnancy With Child Growth

IMPORTANCE

Greater caffeine consumption in pregnancy is associated with reduced birth size, but potential associations with childhood growth are unclear.

OBJECTIVE

To evaluate the associations of pregnancy caffeine and paraxanthine measures with child growth in a contemporary cohort with low caffeine consumption and a historical cohort with high caffeine consumption.

DESIGN, SETTING, AND PARTICIPANTS

The Environmental Influences on Child Health Outcomes cohort of the National Institute of Child Health and Human Development Fetal Growth Studies (ECHO-FGS; 10 sites, 2009-2013) was a pregnancy cohort with 1 child measurement between ages 4 and 8 years (follow-up in 2017-2019). The Collaborative Perinatal Project (CPP) was a pregnancy cohort (12 sites, 1959-1965) with child follow-up through 8 years (1960-1974). The current secondary analysis was conducted in 2021 and 2022.

EXPOSURES

Concentrations of caffeine and its primary metabolite, paraxanthine, were quantified from plasma (ECHO-FGS) and serum (CPP) collected in the first trimester. Cut points for analyses were defined by quartiles in ECHO-FGS and quintiles in CPP.

MAIN OUTCOMES AND MEASURES

Child z scores for body mass index, weight, and height were evaluated, as well as fat mass index and percentage and obesity risk measured at 1 time between age 4 and 8 years in ECHO-FGS. In a secondary analysis of the CPP cohort, child z scores and obesity risk longitudinally through age 8 years were evaluated.

RESULTS

In ECHO-FGS (median caffeine intake <50 mg/d), 788 children (mean [SD] age, 6.8 [1.0] years; 411 boys [52.2%]) of women in the fourth vs first quartile of plasma caffeine concentrations had lower height z scores (β = -0.21; 95% CI, -0.41 to -0.02), but differences in weight z scores were only observed in the third quartile (β = -0.27; 95% CI, -0.47 to -0.07). In CPP, beginning at age 4 years, 1622 children (805 boys [49.7%]) of women in the highest caffeine quintile group had lower height z scores than their peers from the lowest group, with the gap widening with each successive year of age (β = -0.16 [95% CI, -0.31 to -0.01] at 4 years; β = -0.37 [95% CI, -0.57 to -0.16] at 8 years). There were slight reductions in weight at ages 5 to 8 years for children in the third vs first caffeine quintile (β = -0.16 to -0.22). Results were consistent for paraxanthine concentrations in both cohorts.

CONCLUSIONS AND RELEVANCE

Intrauterine exposure to increasing levels of caffeine and paraxanthine, even in low amounts, was associated with shorter stature in early childhood. The clinical implication of reductions in height and weight is unclear; however, the reductions were apparent even with levels of caffeine consumption below clinically recommended guidelines of less than 200 mg per day.

Health Education about Lifestyle-Related Risk Factors in Gynecological and Obstetric Care: A Qualitative Study of Healthcare Providers' Views in Germany

OBJECTIVE

Lifestyle-related risk factors (LRRFs) during pregnancy and lactation are associated with a range of health problems. However, previous studies have shown a large knowledge gap among pregnant women regarding the effects of LRRFs. This study aimed to investigate the role of health education about LRRFs during pregnancy and lactation in gynecological and obstetric care from healthcare providers' (HCPs) point of view.

METHODS

To explore the views of healthcare providers, a qualitative study was performed. In 2019, 22 in-depth interviews were conducted with a purposive sample of 9 gynecologists and 13 midwives. Participants came from different inpatient and outpatient care settings and from rural, urban, and socially deprived areas in southern Germany. All the interviews were tape-recorded and transcribed verbatim. A combined inductive and deductive approach was applied for data analysis.

RESULTS

Interviews with HCPs showed that they were aware of the possible impacts of LRRFs during pregnancy and lactation. They noted the importance of action, specifically among women with low socioeconomic status (SES), migrants, and women with a concerning medical history or other specific needs. However, the interviews showed that, at present, there is no standardized practice of educating patients on LRRFs in routine care. This was attributed to a lack of guidelines and time, unfavorable regulations, and undefined responsibilities. The priority of health education is lower in inpatient healthcare settings as compared to outpatient healthcare settings. HCPs apply a demand-driven healthcare approach, focusing on a woman's medical history, needs, and personal circumstances. HCPs voiced the importance of implementing pre-conception education across different healthcare settings, garnering support from other health organizations, and setting out clearly defined responsibilities among HCPs.

CONCLUSIONS

This qualitative study explored HCPs' perspectives on health education about LRRFs during pregnancy and lactation. The results from this study emphasize the need for a central strategy for health education about LRRFs during pregnancy and lactation in gynecological and obstetric care.

Behavioral, genetic and biochemical changes in the brain of the offspring of female mice treated with caffeine during pregnancy and lactation

The intrauterine environment is a critical location for exposure to exogenous and endogenous factors that trigger metabolic changes through fetal programming. Among the external factors, chemical compounds stand out, which include caffeine, since its consumption is common among women, including during pregnancy. Thereby, the aim of the present study was to evaluate the behavioral, genetic, and biochemical parameters in the offspring of female mice treated with caffeine during pregnancy and lactation. Swiss female mice (60 days old) received tap water or caffeine at 0.3 or 1.0 mg/mL during copulation (7 days), pregnancy (21 days) and lactation (21 days). After the end of the lactation period, the offspring were divided into groups (water, caffeine 0.3 or 1.0 mg/mL) with 20 animals (10 animals aged 30 days and 10 animals aged 60 days per group per sex). Initially, the offspring were submitted to behavioral tasks and then euthanized for genetic and biochemical analysis in the brain (cortex, striatum, and hippocampus). Behavioral changes in memory, depression, and anxiety were observed in the offspring: 30-day-old female offspring at 1.0 mg /mL dose presented anxiogenic behavior and male offspring the 0.3 mg/mL dose at 30 days of age did not alter long-term memory. Furthermore, an increase in DNA damage and oxidative stress in the brain were observed in the offspring of both sexes. Furthermore, there were changes in Ape-1, BAX, and Bcl-2 in the female offspring hippocampus at 30 days of life. Thus, with this study, we can suggest genotoxicity, oxidative stress, and behavioral changes caused by caffeine during pregnancy and lactation in the offspring that were not treated directly, but received through their mothers; thus, it is important to raise awareness regarding caffeine consumption among pregnant and lactating females.

Intrauterine programming of cartilaginous 11β-HSD2 induced by corticosterone and caffeine mediated susceptibility to adult osteoarthritis

Our previous study reported that prenatal caffeine exposure (PCE) could induce chondrodysplasia and increase the susceptibility to osteoarthritis in offspring rats. However, the potential mechanisms and initiating factors remain unknown. This study aims to investigate whether 11β-HSD2, a glucocorticoid-metabolizing enzyme, is involved in the susceptibility of osteoarthritis induced by PCE and to further explore its potential mechanisms and initiating factors. Firstly, we found that PCE reduced cartilage matrix synthesis (aggrecan/Col2a1 expression) in male adult offspring rats and exhibited an osteoarthritis phenotype following chronic stress, which was associated with persistently reduced H3K9ac and H3K27ac levels at the promoter of 11β-HSD2 as well as its expression in the cartilage from fetus to adulthood. The expression of 11β-HSD2, aggrecan and Col2a1 were all decreased by corticosterone in the fetal chondrocytes, while overexpression of 11β-HSD2 could partially alleviate the decrease of matrix synthesis induced by corticosterone in vitro. Furthermore, the glucocorticoid receptor (GR) activated by glucocorticoids directly bonded to the promoter region of 11β-HSD2 to inhibit its expression. Meanwhile, the activated GR reduced the H3K9ac and H3K27ac levels of 11β-HSD2 by recruiting HDAC4 and promoting GR-HDAC4 protein interaction to inhibit the 11β-HSD2 expression. Moreover, caffeine could reduce the expression of 11β-HSD2 by inhibiting the cAMP/PKA signaling pathway but without reducing the H3K9ac and H3K27ac levels of 11β-HSD2, thereby synergistically enhancing the corticosterone effect. In conclusion, the persistently reduced H3K9ac and H3K27ac levels of 11β-HSD2 from fetus to adulthood mediated the inhibition of cartilage matrix synthesis and the increased susceptibility to osteoarthritis. This epigenetic programming change in utero was induced by glucocorticoids with synergistic effect of caffeine.

Differential expression of placental 11β-HSD2 induced by high maternal glucocorticoid exposure mediates sex differences in placental and fetal development

A variety of adverse environmental factors during pregnancy cause maternal chronic stress. Caffeine is a common stressor, and its consumption during pregnancy is widespread. Our previous study showed that prenatal caffeine exposure (PCE) increased maternal blood glucocorticoid levels and caused abnormal development of offspring. However, the placental mechanism for fetal development inhibition caused by PCE-induced high maternal glucocorticoid has not been reported. This study investigated the effects of PCE-induced high maternal glucocorticoid level on placental and fetal development by regulating placental 11β-hydroxysteroid dehydrogenase 2 (11β-HSD2) expression and its underlying mechanism. First, human placenta and umbilical cord blood samples were collected from women without prenatal use of synthetic glucocorticoids. We found that placental 11β-HSD2 expression was significantly correlated with umbilical cord blood cortisol level and birth weight in male newborns but not in females. Furthermore, we established a rat model of high maternal glucocorticoids induced by PCE (caffeine, 60 mg/kg·d, ig), and found that the expression of 11β-HSD2 in male PCE placenta was decreased and negatively correlated with the maternal/fetal/placental corticosterone levels. Meanwhile, we found abnormal placental structure and nutrient transporter expression. In vitro, BeWo cells were used and confirm that 11β-HSD2 mediated inhibition of placental nutrient transporter expression induced by high levels of glucocorticoid. Finally, combined with the animal and cell experiments, we further confirmed that high maternal glucocorticoid could activate the GR-C/EBPα-Egr1 signaling pathway, leading to decreased expression of 11β-HSD2 in males. However, there was no significant inhibition of placental 11β-HSD2 expression, placental and fetal development in females. In summary, we confirmed that high maternal glucocorticoids could regulate placental 11β-HSD2 expression in a sex-specific manner, leading to differences in placental and fetal development. This study provides the theoretical and experimental basis for analyzing the inhibition of fetoplacental development and its sex difference caused by maternal stress.

Prenatal caffeine exposure induced renal developmental toxicity and transgenerational effect in rat offspring

Epidemiological studies revealed that prenatal caffeine exposure (PCE) is associated with adverse gestational outcomes and susceptibility to chronic diseases in offspring, yet the effects of PCE on glomerulosclerosis susceptibility in adult female offspring and its intergenerational transmission remain to be further investigated. Here, we found that PCE caused fetal kidney dysplasia and glomerulosclerosis of the female offspring. Besides, the kidney of F1 offspring in PCE group exhibited the "low expressional programming of AT2R" and "GC-IGF1 programming" alteration. Intergenerational genetic studies revealed that the renal defect and GC-IGF1 programming alteration was inherited to F2 adult female offspring derived from the female germ line, but Low expression of AT2R did not extend to the F2 female offspring. Taken together, PCE caused renal dysplasia and adult glomerulosclerosis in the F1 female offspring, which might be mediated by renal AT2R low expressional programming and GC-IGF1 axis alteration. Furthermore, PCE induced transgenerational toxicity on kidney, and GC-IGF1 programming alteration might be the potential molecular mechanism. This study provided experimental evidence for the mechanism study of the intergenerational inheritance of kidney developmental toxicity caused by PCE.

Prenatal caffeine exposure: association with neurodevelopmental outcomes in 9- to 11-year-old children

BACKGROUND

Despite the widespread use of caffeine including consumption during pregnancy, the effect of prenatal caffeine exposure on child brain development and behavior is unclear.

METHODS

To address this, we used data from the Adolescent Brain and Cognitive Development Study (n = 11,875 children aged 9-11 years from 22 sites across the United States). We explored the associations between prenatal caffeine exposure and various developmental outcomes including birth outcomes, physical health, behavior problems, cognition, substance use and brain structure in children, and evaluated dose effects.

RESULTS

Among 9,978 children (4,745 females) who had valid data for prenatal caffeine exposure and whose mothers did not use drugs of abuse after knowing of pregnancy, 4,170 (41.79%) had no prenatal caffeine exposure, 2,292 (22.97%) had daily, 1,933 (19.37%) had weekly, and 1,583 (15.86%) had less than weekly exposures. Prenatal caffeine exposure including the widely recommended 'safe' dose was associated with greater externalizing problems, whereas greater BMI and soda consumption were only observed in children with high dose exposures (3+ per day). Notably, the effect size for association of externalizing problems with prenatal caffeine exposure was comparable with that reported for prenatal alcohol (The American Journal of Psychiatry, 177, 2020 and 1060) and prenatal cannabis (JAMA Psychiatry, 78, 2020 and 64) exposures from previous ABCD publications. Additionally, prenatal caffeine exposure was associated with brain structural changes that included greater posterior and lower frontal cortical thickness and altered parietooccipital sulcal depth.

CONCLUSIONS

The recommended 'safe' dose of caffeine during pregnancy should be carefully studied to assess whether the behavioral and brain correlates observed here are clinically relevant and determine whether it needs adjustment. Because of the high prevalence of caffeine use in the general population, studies on prenatal exposure to drugs of abuse should include prenatal caffeine use as a covariate.

The impact of socioeconomic deprivation on congenital hand differences: A retrospective cohort study

Socioeconomic deprivation is an established risk factor for a range of adverse perinatal and infant outcomes. The primary aim of this study was to investigate any association between socioeconomic deprivation and the prevalence of Congenital Hand Differences (CHDs). This retrospective cross-sectional study was undertaken at a single tertiary referral center over a five year period (March 2015 to February 2020). The inclusion criterion was all patients referred for a review at a CHD clinic. As a measure of socioeconomic status, patients were assigned to a deprivation quintile using the Scottish Index of Multiple Deprivation (SIMD): quintile 1 indicates the most deprived area and quintile 5 indicates the least deprived area. CHDs were classified according to the Oberg-Manske-Tonkin (OMT) Classification. During the study period 259 patients were identified. The overall prevalence of CHD was 15 per 100,000 per year, mean referral age was 2.6 years (Standard Deviation: 4 years) and 135 patients (52%) were female. Areas of greater social deprivation had a significantly higher prevalence of CHD (22 per 100,000 per year in quintile 1 vs. 13 per 100,000 per year in quintile 5; p < 0.001), surgery (75% of patients in quintile 1 vs 43% of patients in quintile 5; p = 0.003), and younger referral age (1.5 years in quintile 1 vs 4.4 years in quintile 5; p = 0.003). This study has shown a greater CHD prevalence rate amongst patients from more socially deprived areas. In the most deprived group, the patient referral age was also significantly younger and surgical intervention rate was higher.

Maternal caffeine consumption during pregnancy and risk of low birth weight: a dose-response meta-analysis of cohort studies

BACKGROUND & OBJECTIVES

Earlier published studies on maternal caffeine intake during pregnancy in relation to the risk of low birth weight (LBW) (birth weight <2500 g) have indicated conflicting findings. Therefore, the present systematic review and meta-analysis was conducted to examine the association between maternal caffeine intake and risk of LBW.

METHODS

We searched for relevant articles published up to Jan 2021 through PubMed and Scopus. For this purpose, we used MESH (Medical Subject Heading) and non-MESH keywords. Cohort studies that considered maternal caffeine intake as the exposure variable and LBW as the main outcome variable were included in the systematic review. Finally, seven cohort studies were considered in this systematic review and meta-analysis.

RESULTS

Combining seven effect sizes, we found a significant positive association between maternal caffeine intake and risk of LBW (RR: 1.70; 95% CI: 1.19-2.43). We also found that each additional 100-mg per day of maternal caffeine intake was significantly associated with an increased risk of LBW (RR: 1.12; 95% CI: 1.03-1.22; P_{heterogeneity} = 0.020). In addition, nonlinear dose-response analysis showed a significant relationship (P_nonlinearity < 0.001) between maternal caffeine intake and risk of LBW.

CONCLUSIONS

In this systematic review and meta-analysis, we found a significant positive association between maternal caffeine intake and risk of LBW.

Maternal caffeine consumption and pregnancy outcomes: a narrative review with implications for advice to mothers and mothers-to-be

OBJECTIVES

Caffeine is a habit-forming substance consumed daily by the majority of pregnant women. Accordingly, it is important that women receive sound evidence-based advice about potential caffeine-related harm. This narrative review examines evidence of association between maternal caffeine consumption and negative pregnancy outcomes, and assesses whether current health advice concerning maternal caffeine consumption is soundly based.

METHODS

Database searches using terms linking caffeine and caffeinated beverages to pregnancy outcomes identified 1261 English language peer-reviewed articles. Screening yielded a total of 48 original observational studies and meta-analyses of maternal caffeine consumption published in the past two decades. The articles reported results for one or more of six major categories of negative pregnancy outcomes: miscarriage, stillbirth, low birth weight and/or small for gestational age, preterm birth, childhood acute leukaemia, and childhood overweight and obesity.

RESULTS

Of 42 separate sets of findings reported in 37 observational studies, 32 indicated significantly increased caffeine-related risk and 10 suggested no or inconclusive associations. Caffeine-related increased risk was reported with moderate to high levels of consistency for all pregnancy outcomes except preterm birth. Of 11 studies reporting 17 meta-analyses, there was unanimity among 14 analyses in finding maternal caffeine consumption to be associated with increased risk for the four outcome categories of miscarriage, stillbirth, low birth weight and/or small for gestational age, and childhood acute leukaemia. The three remaining meta-analyses were also unanimous in reporting absence of a reliable association between maternal caffeine consumption and preterm birth. No meta-analyses were identified for childhood overweight and obesity, although four of five original observational studies reported significant associations linking maternal caffeine consumption to that outcome category.

CONCLUSIONS

The substantial majority finding from observational studies and meta-analyses is that maternal caffeine consumption is reliably associated with major negative pregnancy outcomes. Reported findings were robust to threats from potential confounding and misclassification. Among both observational studies and meta-analyses, there were frequent reports of significant dose-response associations suggestive of causation, and frequent reports of no threshold of consumption below which associations were absent. Consequently, current evidence does not support health advice that assumes 'moderate' caffeine consumption during pregnancy is safe. On the contrary, the cumulative scientific evidence supports pregnant women and women contemplating pregnancy being advised to avoid caffeine.

The Medicinal Chemistry of Caffeine

The purine alkaloid caffeine is the most widely consumed psychostimulant drug in the world and has multiple beneficial pharmacological activities, for example, in neurodegenerative diseases. However, despite being an extensively studied bioactive natural product, the mechanistic understanding of caffeine's pharmacological effects is incomplete. While several molecular targets of caffeine such as adenosine receptors and phosphodiesterases have been known for decades and inspired numerous medicinal chemistry programs, new protein interactions of the xanthine are continuously discovered providing potentially improved pharmacological understanding and a molecular basis for future medicinal chemistry. In this Perspective, we gather knowledge on the confirmed protein interactions, structure activity relationship, and chemical biology of caffeine on well-known and upcoming targets. The diversity of caffeine's molecular activities on receptors and enzymes, many of which are abundant in the CNS, indicates a complex interplay of several mechanisms contributing to neuroprotective effects and highlights new targets as attractive subjects for drug discovery.

Smoking Cessation during the Second Half of Pregnancy Prevents Low Birth Weight among Australian Born Babies in Regional New South Wales

Smoking during pregnancy is a modifiable risk behavior of adverse health outcomes including low birth weight (LBW), and LBW is a key marker of newborns immediate and future health. This study aimed to examine the association between smoking cessation during the second half of pregnancy and LBW among babies born in Southern New South Wales Local Health District (SNSWLHD). Routinely collected perinatal data on singleton live births for the period 2011–2019 in five public hospitals of SNSWLHD were utilized. Multivariate logistic regression models were fitted to examine the association between smoking cessation during the second half of pregnancy and LBW. Analyses showed that mothers who ceased smoking during the second half of pregnancy were 44% less likely to have LBW babies (adjusted odds ratio (aOR) = 0.56; 95% confidence interval (CI): 0.34, 0.94) compared to those who continued smoking throughout pregnancy. Mothers who reported an average daily dose of 1–10 or >10 cigarettes during the second half of pregnancy were significantly more likely to have babies with LBW than those who ceased smoking during the second half of pregnancy. Early identification of smoking behavior and promotion of smoking-cessation intervention for risk populations including pregnant women within the older age bracket (35–49 years) is imperative to reduce LBW.

Caffeine and Its Neuroprotective Role in Ischemic Events: A Mechanism Dependent on Adenosine Receptors

Ischemia is characterized by a transient, insufficient, or permanent interruption of blood flow to a tissue, which leads to an inadequate glucose and oxygen supply. The nervous tissue is highly active, and it closely depends on glucose and oxygen to satisfy its metabolic demand. Therefore, ischemic conditions promote cell death and lead to a secondary wave of cell damage that progressively spreads to the neighborhood areas, called penumbra. Brain ischemia is one of the main causes of deaths and summed with retinal ischemia comprises one of the principal reasons of disability. Although several studies have been performed to investigate the mechanisms of damage to find protective/preventive interventions, an effective treatment does not exist yet. Adenosine is a well-described neuromodulator in the central nervous system (CNS), and acts through four subtypes of G-protein-coupled receptors. Adenosine receptors, especially A₁ and A_2A receptors, are the main targets of caffeine in daily consumption doses. Accordingly, caffeine has been greatly studied in the context of CNS pathologies. In fact, adenosine system, as well as caffeine, is involved in neuroprotection effects in different pathological situations. Therefore, the present review focuses on the role of adenosine/caffeine in CNS, brain and retina, ischemic events.

Association Between Maternal Caffeine Consumption and Metabolism and Neonatal Anthropometry: A Secondary Analysis of the NICHD Fetal Growth Studies-Singletons

IMPORTANCE

Higher caffeine consumption during pregnancy has been associated with lower birth weight. However, associations of caffeine consumption, based on both plasma concentrations of caffeine and its metabolites, and self-reported caffeinated beverage intake, with multiple measures of neonatal anthropometry, have yet to be examined.

OBJECTIVE

To evaluate the association between maternal caffeine intake and neonatal anthropometry, testing effect modification by fast or slow caffeine metabolism genotype.

DESIGN, SETTING, AND PARTICIPANTS

A longitudinal cohort study, the National Institute of Child Health and Human Development Fetal Growth Studies-Singletons, enrolled 2055 nonsmoking women at low risk for fetal growth abnormalities with complete information on caffeine consumption from 12 US clinical sites between 2009 and 2013. Secondary analysis was completed in 2020.

EXPOSURES

Caffeine was evaluated by both plasma concentrations of caffeine and paraxanthine and self-reported caffeinated beverage consumption measured/reported at 10-13 weeks gestation. Caffeine metabolism defined as fast or slow using genotype information from the single nucleotide variant rs762551 (CYP1A2*1F).

MAIN OUTCOMES AND MEASURES

Neonatal anthropometric measures, including birth weight, length, and head, abdominal, arm, and thigh circumferences, skin fold and fat mass measures. The β coefficients represent the change in neonatal anthropometric measure per SD change in exposure.

RESULTS

A total of 2055 participants had a mean (SD) age of 28.3 (5.5) years, mean (SD) body mass index of 23.6 (3.0), and 580 (28.2%) were Hispanic, 562 (27.4%) were White, 518 (25.2%) were Black, and 395 (19.2%) were Asian/Pacific Islander. Delivery occurred at a mean (SD) of 39.2 (1.7) gestational weeks. Compared with the first quartile of plasma caffeine level (≤28 ng/mL), neonates of women in the fourth quartile (>659 ng/mL) had lower birth weight (β = -84.3 g; 95% CI, -145.9 to -22.6 g; P = .04 for trend), length (β = -0.44 cm; 95% CI, -0.78 to -0.12 cm; P = .04 for trend), and head (β = -0.28 cm; 95% CI, -0.47 to -0.09 cm; P < .001 for trend), arm (β = -0.25 cm; 95% CI, -0.41 to -0.09 cm: P = .02 for trend), and thigh (β = -0.29 cm; 95% CI, -0.58 to -0.04 cm; P = .07 for trend) circumference. Similar reductions were observed for paraxanthine quartiles, and for continuous measures of caffeine and paraxanthine concentrations. Compared with women who reported drinking no caffeinated beverages, women who consumed approximately 50 mg per day (~ 1/2 cup of coffee) had neonates with lower birth weight (β = -66 g; 95% CI, -121 to -10 g), smaller arm (β = -0.17 cm; 95% CI, -0.31 to -0.02 cm) and thigh (β = -0.32 cm; 95% CI, -0.55 to -0.09 cm) circumference, and smaller anterior flank skin fold (β = -0.24 mm; 95% CI, -0.47 to -0.01 mm). Results did not differ by fast or slow caffeine metabolism genotype.

CONCLUSIONS AND RELEVANCE

In this cohort study, small reductions in neonatal anthropometric measurements with increasing caffeine consumption were observed. Findings suggest that caffeine consumption during pregnancy, even at levels much lower than the recommended 200 mg per day of caffeine, are associated with decreased fetal growth.

Relationship between Intraocular Pressure and Coffee Consumption in a Japanese Population without Glaucoma: The Nagahama Study

PURPOSE

To evaluate the association between daily coffee consumption and intraocular pressure (IOP) in healthy persons without glaucoma and the association between daily coffee consumption and history of glaucoma.

DESIGN

Cross-sectional study.

PARTICIPANTS

A total of 9850 individuals participated in the first follow-up of the Nagahama Prospective Cohort for Comprehensive Human Bioscience (the Nagahama Study) conducted between 2013 and 2016.

METHODS

All participants underwent a standardized ophthalmic examination. Self-reporting questionnaires were completed by all participants. First, the association between habitual coffee consumption and IOP among nonglaucoma individuals was evaluated by a multivariate linear regression analysis, adjusting for possible confounders. Second, the association between habitual coffee consumption and history of glaucoma also was evaluated using a multivariate logistic regression analysis.

MAIN OUTCOME MEASURES

The association between habitual coffee consumption and IOP among nonglaucoma individuals.

RESULTS

Of 9850 participants, 9418 did not have history of glaucoma. Among these participants, the mean ± standard deviation IOP of both eyes was 14.7 ± 2.9 mmHg. The multivariate regression analysis revealed that habitual coffee consumption was associated significantly with IOP (P < 0.001): the higher the consumption of coffee, the lower the IOP of an individual. The IOP of the group who consumed coffee most frequently (3 times daily or more) was 0.4 mmHg lower (95% confidence interval, 0.2-0.5 mmHg lower) than that of the group that consumed coffee least frequently (less than once daily). However, the logistic regression analysis showed that habitual coffee consumption was not associated significantly with history of glaucoma (P = 0.53).

CONCLUSIONS

Frequent coffee consumption was associated with a slightly lower IOP in people without glaucoma but was not associated with a decreased risk of glaucoma developing. Additional experimental studies are needed to examine the effects of coffee on IOP and glaucoma risk.

Caffeine: A potential strategy to improve survival of neonatal pigs and sheep

Caffeine is commonly used to treat pre-and postnatal injuries, including apnoea in premature infants, as well as neurological impairment caused by hypoxia or asphyxiation often associated with difficult birthing. As an adenosine antagonist, caffeine is metabolised rapidly and transported into many tissues. Caffeine stimulates the brain respiratory centre, improving respiratory function in immature infants or neonates, provides neuroprotection to the fetal brain, and initiates non-shivering thermoregulation increasing metabolic rates. Recently, potential benefits of caffeine for animal production have been investigated. This has particularly occurred in pig production, where large litters are associated with relatively long parturition durations, and piglets born near the end of the parturition period have an increased risk of mortality due to asphyxia-related birthing injury. Similarly, in sheep, dystocia or prolonged parturition is a significant problem, where neonatal injury, dystocia and death in utero contributes to approximately 46 % of lamb mortalities. Within these two livestock production systems, large prevalence's of neonatal mortality is a persistent issue contributing to lost revenue, as well as being a significant animal welfare concern. Pre-partum maternal caffeine supplementation is a promising strategy to reduce neonatal mortality; however, there needs to be refinement of appropriate quantities administered, duration and administration pathway to provide producers with an efficient and cost-effective method to reduce mortality rates and increase production output. The information in this review details effects, benefits and important considerations regarding caffeine use in animal production, and identifies areas of limited knowledge where further research is needed.

Maternal Metabolome in Pregnancy and Childhood Asthma or Recurrent Wheeze in the Vitamin D Antenatal Asthma Reduction Trial

The in utero environment during pregnancy has important implications for the developing health of the child. We aim to examine the potential impact of maternal metabolome at two different timepoints in pregnancy on offspring respiratory health in early life. In 685 mother-child pairs from the Vitamin D Antenatal Asthma Reduction Trial, we assessed the prospective associations between maternal metabolites at both baseline (10–18 weeks gestation) and third trimester (32–38 weeks gestation) and the risk of child asthma or recurrent wheeze by age three using logistic regression models accounting for confounding factors. Subgroup analyses were performed by child sex. Among 632 metabolites, 19 (3.0%) and 62 (9.8%) from baseline and third trimester, respectively, were associated with the outcome (p-value < 0.05). Coffee-related metabolites in the maternal metabolome appeared to be of particular importance. Caffeine, theophylline, trigonelline, quinate, and 3-hydroxypyridine sulfate were inversely associated with asthma risk at a minimum of one timepoint. Additional observations also highlight the roles of steroid and sphingolipid metabolites. Overall, there was a stronger relationship between the metabolome in later pregnancy and offspring asthma risk. Our results suggest that alterations in prenatal metabolites may act as drivers of the development of offspring asthma.

Maternal intake of caffeinated products and birth defects: a systematic review and meta-analysis of observational studies

Caffeinated products are frequently consumed by women of childbearing age worldwide. It still unclear that whether maternal intake of caffeine associated with an increased risk of birth defects. We searched the databases of PubMed, Embase, the Cochrane Library, and Web of Science for eligible studies through July 2020. All studies examining the association between maternal consumption of caffeine or caffeinated products and birth defects were included. Twenty-nine studies were included in this meta-analysis. Among all the birth defects, maternal caffeine consumption was associated with a higher risk of cardiovascular defects, [odds ratio (OR) 1.17; 95% confidence interval (CI), 1.07-1.28], craniofacial defects (OR 1.09; 95% CI, 1.02-1.17), alimentary tract defects (OR 1.35; 95% CI, 1.16-1.56), and abdominal-wall defects and hernia (OR 1.13; 95% CI, 1.03-1.25). No association was found between maternal caffeine intake and musculoskeletal system defects, genitourinary system defects, nervous system defects, or chromosomal abnormalities. Meanwhile, all three of the caffeine consumption categories (low, moderate, and high) were associated with a higher risk of cardiovascular defects and alimentary tract defects.

Consumption of non-nutritive sweeteners during pregnancy

In an effort to reduce sugar consumption to prevent diabetes mellitus and cardiovascular diseases, "sugar-free" or "no added sugar" products that substitute sugar with non-nutritive sweeteners (NNSs) (eg, Splenda, Sweet'N Low, and Stevia) have become increasingly popular. The use of these products during pregnancy has also increased, with approximately 30% of pregnant women reporting intentional NNS consumption. In clinical studies with nonpregnant participants and animal models, NNSs were shown to alter gut hormonal secretion, glucose absorption, appetite, kidney function, in vitro insulin secretion, adipogenesis, and microbiome dysbiosis of gut bacteria. In pregnant animal models, NNS consumption has been associated with altered sweet taste preference later in life and metabolic dysregulations in the offspring (eg, elevated body mass index, increased risk of obesity, microbiome dysbiosis, and abnormal liver function tests). Despite the accumulating evidence, no specific guidelines for NNS consumption are available for pregnant women. Furthermore, there are limited clinical studies on the effects of NNS consumption during pregnancy and postpartum and long-term outcomes in the offspring.

Caffeine, alcohol, khat, and tobacco use during pregnancy in Butajira, South Central Ethiopia

Background

The use of excessive caffeine and consumption of alcohol, cigarette, and khat during pregnancy can result in adverse health effects on the fetus. The World Health Organization (WHO) recommends a daily caffeine intake not exceeding 300 mg. Likewise, pregnant women are recommended to avoid alcohol, khat and tobacco use. However, the prevalence’s of the use of substances among pregnant women were not well studied in developing countries such as Ethiopia. Therefore, the study aimed to estimate the prevalence of caffeine and alcohol consumption, khat chewing, and tobacco use during pregnancy and identify key factors associated with excess caffeine consumption.

Methods

We conducted a community based cross-sectional study and used a random sampling technique to recruit 352 pregnant women. We adapted a questionnaire from Caffeine Consumption Questionnaire-Revised (CCQ-R), Alcohol Use Disorder Identification Test (AUDIT), Global Adult Tobacco Survey (GATS), and Ethiopian Demographic Health Survey 2016 for caffeine, alcohol consumption, tobacco use, and khat chewing assessment, respectively. We conducted non-consecutive two days 24-hour recall to determine the habitual intake of caffeine from caffeinated beverages and foods. Prevalence with 95% confidence interval was estimated for excess caffeine intake per day, alcohol consumption, khat chewing, and passive tobacco smoking. We ran a multivariable binary logistic regression model to identify factors associated with excess caffeine intake.

Results

Almost all pregnant women (98.2%) consumed caffeine as estimated using the 2 days 24-hour average. The median daily caffeine intake was 170.5 mg and ranged from 0.00 mg to 549.8 mg per day. In addition, 17.6% (95% CI: 13.9%, 22.0%) of them had a daily caffeine consumption of 300 mg and above exceeding the WHO recommended daily caffeine intake during pregnancy. The prevalence of alcohol consumption and Khat chewing were 10.0% (95% CI: 7.2%, 13.7%) and 35.8% (95% CI: 30.8, 41.0%) respectively. None of the pregnant women were active tobacco smokers. However, 23.2% (95% CI: 19.0, 28.0%) were passive tobacco smokers. We found that pregnant women in the richest wealth quintile (AOR = 3.66; 95% CI: 1.13, 11.88), and the first trimester of pregnancy (AOR = 4.04; 95% CI: 1.26, 13.05) had higher odds of consuming excessive caffeine.

Conclusions

The study showed a considerable magnitude of substance use among pregnant women in the study area. Given this findings, we recommend, programs and services focusing on pregnant women to consider addressing substance use.

Associations of maternal caffeine intake during pregnancy with abdominal and liver fat deposition in childhood

BACKGROUND

Maternal caffeine intake during pregnancy is associated with an increased risk of childhood obesity. Studies in adults suggest that caffeine intake might also directly affect visceral and liver fat deposition, which are strong risk factors for cardio-metabolic disease.

OBJECTIVE

To assess the associations of maternal caffeine intake during pregnancy with childhood general, abdominal, and liver fat mass at 10 years of age.

METHODS

In a population-based cohort from early pregnancy onwards among 4770 mothers and children, we assessed maternal caffeine intake during pregnancy and childhood fat mass at age 10 years.

RESULTS

Compared with children whose mothers consumed <2 units of caffeine per day during pregnancy, those whose mothers consumed 4-5.9 and ≥6 units of caffeine per day had a higher body mass index, total body fat mass index, android/gynoid fat mass ratio, and abdominal subcutaneous and visceral fat mass indices. Children whose mothers consumed 4-5.9 units of caffeine per day had a higher liver fat fraction. The associations with abdominal visceral fat and liver fat persisted after taking childhood total body fat mass into account.

CONCLUSIONS

High maternal caffeine intake during pregnancy was associated with higher childhood body mass index, total body fat, abdominal visceral fat, and liver fat. The associations with childhood abdominal visceral fat and liver fat fraction were independent of childhood total body fat. This suggests differential fat accumulation in these depots, which may increase susceptibility to cardio-metabolic disease in later life.

Impacts of Caffeine during Pregnancy

Epidemiological studies have revealed that caffeine consumption during pregnancy is associated with adverse gestational outcomes, yet the underlying mechanisms remain obscure. Recent animal studies with physiologically relevant dosages have begun to dissect adverse effects of caffeine during pregnancy with respect to oviduct contractility, embryo development, uterine receptivity, and placentation that jointly contribute to pregnancy complications. Interestingly, caffeine's effects are highly variable between individual animals under well-controlled experimental settings, suggesting the possibility of epigenetic regulation of these phenotypes, in addition to genetic variants. Moreover, caffeine exposure during sensitive windows of pregnancy may induce epigenetic changes in the developing fetus or even the germ cells to cause adult-onset diseases in subsequent generations. We discuss these research frontiers in light of emerging data.

Mother-Infant Bonding and Emotional Availability at 12-Months of Age: The Role of Early Postnatal Bonding, Maternal Substance Use and Mental Health

INTRODUCTION

The quality of the mother-child relationship in the first year of life has far reaching implications across the life course (Bornstein in Annu Rev Psychol 65:121-158, 2014). Yet little is known about predictors of maternal bonding and emotional availability in early infancy. In this study we examined the extent to which postnatal bonding, maternal mental health, and substance use at 8-weeks postpartum predicted mother-infant bonding (self-report) and mother emotional availability (observational) at 12-months of age.

METHODS

Data were obtained from an Australian longitudinal cohort study of pregnancy (n = 308). Data were collected during pregnancy, at birth, and postnatally at 8-weeks and 12-months.

RESULTS

The results show strong continuity between postnatal bonding at 8-weeks and 12-months. Early postpartum stress and depression were associated with bonding at 12-months; however, the effect did not persist after adjustment for bonding at 8-weeks. Tobacco use at 8-weeks, but no other indicators of mental health, predicted lower emotional availability scores at 12-months.

DISCUSSION

Results suggest that the mother's felt bond to her child is stable across the first year of life and that early bonding is a more robust indicator of bonding at 12-months than a mother's mental health or substance use. These findings point to the importance of clinical and public health investments in establishing a strong bond between mother and child in the early postpartum period.

Caffeine consumption during early pregnancy impairs oviductal embryo transport, embryonic development and uterine receptivity in mice

Caffeine consumption has been widely used as a central nervous system stimulant. Epidemiological studies, however, have suggested that maternal caffeine exposure during pregnancy is associated with increased abnormalities, including decreased fertility, delayed conception, early spontaneous abortions, and low birth weight. The mechanisms underlying the negative outcomes of caffeine consumption, particularly during early pregnancy, remain unclear. In present study, we found that pregnant mice treated with moderate (5 mg/kg) or high (30 mg/kg) dosage of caffeine (intraperitoneally or orally) during preimplantation resulted in retention of early embryos in the oviduct, defective embryonic development, and impaired embryo implantation. Transferring normal blastocysts into the uteri of caffeine-treated pseudopregnant females also showed abnormal embryo implantation, thus indicating impaired uterine receptivity by caffeine administration. The remaining embryos that managed to implant after caffeine treatment also showed increased embryo resorption rate and abnormal development at mid-term stage, and decreased weight at birth. In addition to a dose-dependent effect, significant variations between individual mice under the same caffeine dosage were also observed, suggesting different sensitivities to caffeine, similar to that observed in human populations. Collectively, our data revealed that caffeine exposure during early pregnancy impaired oviductal embryo transport, embryonic development, and uterine receptivity, which are responsible for abnormal implantation and pregnancy loss. The study raises the concern of caffeine consumption during early stages of pregnancy.