Consequences on the newborn of chronic maternal consumption of coffee during gestation and lactation: a review

Maternal coffee consumption and biomarkers of reproductive health in young, adult sons: a cohort study

It has been proposed that poor semen quality may have its origins from fetal programming due to environmental factors. We investigated whether maternal coffee consumption during early pregnancy was associated with biomarkers of reproductive health in adult sons in the Fetal Programming of Semen Quality (FEPOS) cohort. In 2017-2019, 1058 young men provided a semen and blood sample and self-measured their testis volume. Daily maternal coffee consumption was reported by the mothers around gestational week 17. We estimated relative percentage differences with 95 % confidence intervals (CI) for semen quality measures, testis volume, and reproductive hormone levels according to maternal coffee consumption during pregnancy. Maternal coffee consumption (yes/no (reference)) was associated with lower semen volume (-7.0 % (95 % CI:-12.9;-0.7)), lower proportion of morphologically normal spermatozoa (-8.3 % (95 % CI:-16.5;0.8)), higher proportion of non-progressive and immotile spermatozoa (4.3 % (95 % CI:-1.5;10.3)), and lower testis volume (-4.8 % (95 % CI:-9.0;-0.4)). No indication of a dose-response association or threshold effects was observed in the categorized and continuous analyses. No associations with reproductive hormone levels were observed in any of the analyses. Overall, the study does not provide obvious indications that maternal coffee consumption in early pregnancy deteriorates male offspring fecundity. While some minor changes were observed, most estimates were small with confidence intervals overlapping the null. Future studies, preferably with greater exposure contrast, are warranted before a conclusion can be drawn as to whether maternal coffee consumption during pregnancy constitutes a risk for reproductive health in adult sons.

Nutritional and Non-nutritional Composition of Human Milk Is Modulated by Maternal, Infant, and Methodological Factors

Human milk (HM) is dynamic and shows a high inter- and intra-individual variability. To characterize HM with precision, it is necessary to understand the factors that modulate its composition. The objective of this narrative review is to summarize the maternal, infant and methodological factors that affect HM composition. We searched SCOPUS and PubMed databases for articles related to factors that are known to or could potentially influence HM composition and volume across lactation periods. Our comprehensive review encompasses various maternal-, infant-related, and methodological factors that modulate aspects of HM composition including macro- and micronutrients, vitamins and minerals, as well as volume. The most profound changes were observed in HM lipids and lipophiles. Evidence exists for many of the infant-related factors known to affect the nutritive and non-nutritive components of HM (e.g., birth weight, gestational age, infant age/stage of lactation). In contrast, less is known with respect to maternal factors; where there is either limited research or conflicting evidence (e.g., maternal lifestyle, obstetric history, medical conditions), except for the mother's diet, for which there is a relatively well-established understanding. Equally, although many of the methodological factors (e.g., HM sampling, handling and analytics) are known to impact HM composition, few studies have investigated this as a primary outcome, making it an important area of future research in HM. Here we propose a systematic capture of numerous maternal- and infant-related characteristics to facilitate associative comparisons of HM data within and across studies. Additionally, it would be prudent to standardize the methodological aspects known to affect HM composition in analytics, not only for HM lipids and lipophiles, but also for those nutrients whose variability is yet less well-understood. Defining the factors determining HM composition with accuracy will open perspectives for maternal intervention to optimize milk composition for specific needs of infants.

Potential beneficial effects of caffeine administration in the neonatal period of an animal model of schizophrenia

Obstetric complications, like maternal hypertension and neonatal hypoxia, disrupt brain development, leading to psychiatry disorders later in life, like schizophrenia. The exact mechanisms behind this risk are not yet well known. Spontaneously hypertensive rats (SHR) are a well-established model to study neurodevelopment of schizophrenia since they exhibit behavioral alterations mimicking schizophrenia that can be improved with antipsychotic drugs. SHR mothers are hypertensive, and the SHR offspring develop in preeclampsia-like conditions. Hypoxic conditions increase levels of adenosine, which play an important role in brain development. The enhanced levels of adenosine at birth could be related to the future development of schizophrenia. To investigate this hypothesis adenosine levels of brain neonatal Wistar rats and SHR were quantified. After that, caffeine, an antagonist of adenosinergic system, was administrated on PND (postnatal day) 7 (neurodevelopmental age similar to a human at delivery) and rats were observed at adolescent and adult ages. We also investigated the acute effects of caffeine at adolescent and adult ages. SHR control adolescent and adult groups presented behavioral deficits like hyperlocomotion, deficit in social interaction (SI), and contextual fear conditioning (CFC). In SHR, neonatal caffeine treatment on PND 7 normalized hyperlocomotion, improved SI, and CFC observed at adolescent period and adult ages, showing a beneficial effect on schizophrenia-like behaviors. Wistar rats neonatally treated with caffeine exhibited hyperlocomotion, deficit in SI and CFC when observed at adolescent and adult ages. Acutely caffeine treatment administrated at adolescent and adult ages increased locomotion and decreased SI time of Wistar rats and impair CFC in adult Wistars. No effects were observed in SHR. In conclusion, caffeine can be suggested as a useful drug to prevent behavioral deficits observed in this animal model of prenatal hypoxia-induced schizophrenia profile when specifically administered on PND 7.

Energy Drinks: Implications for the Breastfeeding Mother

Breastfeeding women may experience disrupted sleep schedules and be tempted to turn to popular energy drinks to reduce fatigue and enhance alertness, prompting the question: What are the maternal and child health implications for breastfeeding mothers consuming energy drinks? Caffeine and vitamin-rich energy drinks contain a variety of herbal ingredients and vitamins; however, ingredient amounts may not be clearly disclosed on product labels. Interactions between herbal ingredients and caffeine are understudied and not well defined in the literature. Some infants can be sensitive to caffeine and display increased irritability and sleep disturbances when exposed to caffeine from breastmilk. Breastfeeding women who consume energy drinks may be ingesting herbal ingredients that have not undergone scientific evaluation, and if taking prenatal vitamins, may unknowingly exceed the recommended daily intake. Caffeinated products are marketed in newer ways, fueling concerns about health consequences of caffeine exposure. We present implications associated with consumption of caffeine and vitamin-rich energy drinks among breastfeeding women. Product safety, labeling, common ingredients, potential interactions, and clinical implications are discussed. Healthcare providers should encourage breastfeeding women to read product labels for ingredients, carbohydrate content, serving size, and to discourage consumption of energy drinks when breastfeeding and/or taking prenatal vitamins, to avoid potential vitamin toxicity.

Maternal exposures and risk of oral clefts in South Vietnam

BACKGROUND

Oral clefts are among the most common congenital anomalies. Most studies on risk factors of oral clefts have been carried out in developed countries. We investigated the associations between maternal exposures in the first trimester and oral clefts in South Vietnam.

METHODS

We conducted a hospital-based case-control study during October 2014-November 2015. Cases included 170 patients with nonsyndromic cleft lip with or without cleft palate and those with cleft palate only. Controls were 170 children without oral clefts, matched to each case by age and gender. Mothers were interviewed using structured questionnaire. We performed conditional logistic regression to estimate odds ratios (ORs) and 95% confidence intervals (CIs).

RESULTS

Passive smoking was associated with increased risk of oral clefts in univariate analysis, but not in multivariable analysis (adjusted OR [aOR] = 1.68; 95% CI, 0.53-5.37). No association was observed between liver intake and oral clefts. Compared with nondrinkers, mothers who reported consumption of caffeine-containing beverages were more likely to have an infant with oral cleft (aOR = 5.89; 95% CI, 1.08-32.00). Periconceptional use of folic acid and multivitamins supplementation was associated with reduced risk of oral clefts (aOR = 0.01; 95% CI, 0.00-0.09 and aOR = 0.03; 95% CI, 0.01-0.13, respectively).

CONCLUSIONS

The results suggest no associations of maternal passive smoking or liver intake with oral clefts. Periconceptional use of folic acid or multivitamins may protect against oral clefts. Further studies are warranted to examine the roles of caffeine consumption in pregnant mothers on occurrence of oral clefts in offspring.

Lifestyle INtervention for Diabetes prevention After pregnancy (LINDA-Brasil): study protocol for a multicenter randomized controlled trial

BACKGROUND

Gestational diabetes mellitus (GDM), a hyperglycemic state detected during pregnancy, is an established risk factor for diabetes. However, treatment during pregnancy in and of itself is not able to eliminate this risk, and a considerable fraction of women with GDM will develop frank diabetes in the decade following pregnancy. Our aim is to conduct a multicenter randomized controlled trial to investigate the effectiveness of a lifestyle intervention program implemented after a pregnancy complicated by GDM in delaying or preventing the development of type 2 diabetes.

METHODS

Women aged 18 or older identified as having recent GDM are recruited and followed by telephone to assess eligibility for the trial. To be eligible, women must have used insulin during pregnancy or present intermediate hyperglycemia postpartum. Women are encouraged to enter the trial as early as 10 weeks, and are permitted to do so up to 2 years after a pregnancy with GDM. An estimated 740 women will be randomized to either conventional care or to coach-based interventions focused on breastfeeding, weight loss, healthy eating, and increased physical activity, and predominantly delivered by telephone. Women are followed annually to detect new onset diabetes, the primary outcome, and additional secondary outcomes which include reversion to normoglycemia, weight loss, physical activity and fitness, and insulin resistance.

DISCUSSION

Though previous studies have demonstrated that type 2 diabetes can be delayed or prevented, no study has yet demonstrated the feasibility and effectiveness of similar interventions implemented in the postpartum period for women with recent GDM. If shown to be successful, this approach could become an important means of preventing diabetes in primary care settings.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02327286; Registered 23 December 2014.

Assessing developmental toxicity of caffeine and sweeteners in medaka (Oryzias latipes)

The use of artificial sweeteners (ASWs) has increased and become more widespread, and consequently ASWs have appeared in aquatic environments around the world. However, their safety to the health of humans and wildlife remains inconclusive. In this study, using medaka embryos (Oryzias latipes), we investigated developmental toxicity of aspartame (ASP) and saccharin (SAC). Since ASWs are often consumed with caffeine (CAF) and CAF with sucrose (SUC), we tested biological activities of these four substances and the mixtures of CAF with each sweetener. The embryos were exposed to ASP at 0.2 and 1.0 mM, SAC at 0.005 and 0.050 mM, CAF at 0.05 and 0.5 mM, or SUC at 29 and 146 mM, starting from less than 5 h post fertilization until hatch. Control embryos were treated with embryo solution only. Several endpoints were used to evaluate embryonic development. Some of the hatchlings were also tested for anxiety-like behavior with the white preference test. The results showed that all four substances and the mixtures of CAF with the sweeteners affected development. The most sensitive endpoints were the heart rate, eye density, and hatchling body length. The hatchlings of several treatment groups also exhibited anxiety-like behavior. We then used the Integrated Biological Response (IBR) as an index to evaluate the overall developmental toxicity of the substances. We found that the ranking of developmental toxicity was SAC > CAF > ASP > SUC, and there was a cumulative effect when CAF was combined with the sweeteners.

Executive summary: Evaluating the evidence base to support the inclusion of infants and children from birth to 24 mo of age in the Dietary Guidelines for Americans--"the B-24 Project"

The Dietary Guidelines for Americans (DGA) are the cornerstone of US government efforts to promote health and prevent disease through diet and nutrition. The DGA currently provides guidelines for ages ≥ 2 y. In an effort to determine the strength of the evidence to support the inclusion of infants and children from birth to age 24 mo, the partner agencies led by the Department of Health and Human Services Office of Disease Prevention and Health Promotion and the USDA Center for Nutrition Program and Policy initiated the project entitled "Evaluating the evidence base to support the inclusion of infants and children from birth to 24 months of age in the Dietary Guidelines for Americans--the B-24 Project." This project represents the first step in the process of applying systematic reviews to the process of deciding whether the evidence is sufficient to include this age group in future editions of the DGA. This supplement includes the B-24 Executive Summary, which describes the B-24 Project and the deliberations of the 4 working groups during the process of developing priority topics for the systematic review, and a research agenda to address the critical gaps. Also included in this supplement issue is an article on the Nutrition Evidence Library methodology for developing systematic review questions and articles from the invited content presenters at the B-24 Prime meeting.

The Janus face of caffeine

Caffeine is certainly the psychostimulant substance most consumed worldwide. Over the past years, chronic consumption of caffeine has been associated with prevention of cognitive decline associated to aging and mnemonic deficits of brain disorders. While its preventive effects have been reported extensively, the cognitive enhancer properties of caffeine are relatively under debate. Surprisingly, there are scarce detailed ontogenetic studies focusing on neurochemical parameters related to the effects of caffeine during prenatal and earlier postnatal periods. Furthermore, despite the large number of epidemiological studies, it remains unclear how safe is caffeine consumption during pregnancy and brain development. Thus, the purpose of this article is to review what is currently known about the actions of caffeine intake on neurobehavioral and adenosinergic system during brain development. We also reviewed other neurochemical systems affected by caffeine, but not only during brain development. Besides, some recent epidemiological studies were also outlined with the control of "pregnancy signal" as confounding variable. The idea is to tease out how studies on the impact of caffeine consumption during brain development deserve more attention and further investigation.

Maternal caffeine consumption and infant nighttime waking: prospective cohort study

OBJECTIVE

Coffee and other caffeinated beverages are commonly consumed in pregnancy. In adults, caffeine may interfere with sleep onset and have a dose-response effect similar to those seen during insomnia. In infancy, nighttime waking is a common event. With this study, we aimed to investigate if maternal caffeine consumption during pregnancy and lactation leads to frequent nocturnal awakening among infants at 3 months of age.

METHODS

All children born in the city of Pelotas, Brazil, during 2004 were enrolled on a cohort study. Mothers were interviewed at delivery and after 3 months to obtain information on caffeine drinking consumption, sociodemographic, reproductive, and behavioral characteristics. Infant sleeping pattern in the previous 15 days was obtained from a subsample. Night waking was defined as an episode of infant arousal that woke the parents during nighttime. Multivariable analysis was performed by using Poisson regression.

RESULTS

The subsample included 885 of the 4231 infants born in 2004. All but 1 mother consumed caffeine in pregnancy. Nearly 20% were heavy consumers (≥300 mg/day) during pregnancy and 14.3% at 3 months postpartum. Prevalence of frequent nighttime awakeners (>3 episodes per night) was 13.8% (95% confidence interval: 11.5%-16.0%). The highest prevalence ratio was observed among breastfed infants from mothers consuming ≥300 mg/day during the whole pregnancy and in the postpartum period (1.65; 95% confidence interval: 0.86-3.17) but at a nonsignificant level.

CONCLUSIONS

Caffeine consumption during pregnancy and by nursing mothers seems not to have consequences on sleep of infants at the age of 3 months.

Evaluation of the reproductive and developmental risks of caffeine

A risk analysis of in utero caffeine exposure is presented utilizing epidemiological studies and animal studies dealing with congenital malformation, pregnancy loss, and weight reduction. These effects are of interest to teratologists, because animal studies are useful in their evaluation. Many of the epidemiology studies did not evaluate the impact of the "pregnancy signal," which identifies healthy pregnancies and permits investigators to identify subjects with low pregnancy risks. The spontaneous abortion epidemiology studies were inconsistent and the majority did not consider the confounding introduced by not considering the pregnancy signal. The animal studies do not support the concept that caffeine is an abortafacient for the wide range of human caffeine exposures. Almost all the congenital malformation epidemiology studies were negative. Animal pharmacokinetic studies indicate that the teratogenic plasma level of caffeine has to reach or exceed 60 µg/ml, which is not attainable from ingesting large amounts of caffeine in foods and beverages. No epidemiological study described the "caffeine teratogenic syndrome." Six of the 17 recent epidemiology studies dealing with the risk of caffeine and fetal weight reduction were negative. Seven of the positive studies had growth reductions that were clinically insignificant and none of the studies cited the animal literature. Analysis of caffeine's reproductive toxicity considers reproducibility and plausibility of clinical, epidemiological, and animal data. Moderate or even high amounts of beverages and foods containing caffeine do not increase the risks of congenital malformations, miscarriage or growth retardation. Pharmacokinetic studies markedly improve the ability to perform the risk analyses.

Maternal consumption of coffee and caffeine-containing beverages and oral clefts: a population-based case-control study in Norway

A large, population-based case-control study of facial clefts was carried out in Norway between 1996 and 2001. The study included 573 cases -- 377 with cleft lip with or without cleft palate and 196 with cleft palate only -- and 763 randomly selected controls. Maternal consumption of coffee and other caffeine-containing beverages in early pregnancy was recorded shortly after birth. Compared with that for no coffee consumption, the adjusted odds ratios for cleft lip with or without cleft palate were 1.39 (95% confidence interval: 1.01, 1.92) for less than 3 cups a day and 1.59 (95% confidence interval: 1.05, 2.39) for 3 cups or more. Coffee consumption was not associated with risk of cleft palate only (for > or = 3 cups vs. none, adjusted odds ratio = 0.96, 95% confidence interval: 0.55, 1.67). Tea consumption was associated with a reduced odds ratio of both cleft lip with or without cleft palate and cleft palate only. There was little evidence of an association between caffeine exposure and clefts when all sources of caffeine were considered. Adjustment for known confounding factors in general had minor effects on risk estimates. Still, the authors could not rule out the possibility of uncontrolled confounding by factors associated with the habit of drinking coffee.

Is coffee a functional food?

Definitions of functional food vary but are essentially based on foods' ability to enhance the quality of life, or physical and mental performance, of regular consumers. The worldwide use of coffee for social engagement, leisure, enhancement of work performance and well-being is widely recognised. Depending on the quantities consumed, it can affect the intake of some minerals (K, Mg, Mn, Cr), niacin and antioxidant substances. Epidemiological and experimental studies have shown positive effects of regular coffee-drinking on various aspects of health, such as psychoactive responses (alertness, mood change), neurological (infant hyperactivity, Alzheimer's and Parkinson's diseases) and metabolic disorders (diabetes, gallstones, liver cirrhosis), and gonad and liver function. Despite this, most reviews do not mention coffee as fulfilling the criteria for a functional food. Unlike other functional foods that act on a defined population with a special effect, the wide use of coffee-drinking impacts a broad demographic (from children to the elderly), with a wide spectrum of health benefits. The present paper discusses coffee-drinking and health benefits that support the concept of coffee as a functional food.

Stress in pregnancy and infant HPA axis function: conceptual and methodological issues relating to the use of salivary cortisol as an outcome measure

Problems regulating behaviour and emotions in infancy may be a risk factor for the development of psychopathology later in life. Compelling evidence from animal models suggests that one potential pathway to early dysregulation is fetal programming of the hypothalamic-pituitary-adrenal (HPA) axis. According to this model, prenatal maternal stress and anxiety during sensitive periods of development can lead to enduring changes in fetal and offspring neurodevelopment and behaviour. While there is emerging evidence from human studies to suggest a link between maternal negative mood states in pregnancy and various cognitive, behavioural, and emotional disturbances in offspring, it is not yet clear whether the programming mechanism demonstrated in animal studies also applies to humans. Few studies have directly assessed HPA axis function in the infants of prenatally stressed women. Research in this area has been constrained by a number of measurement challenges unique to the assessment of cortisol in infants. This paper discusses these challenges with a view to stimulating further research in the area.

Effect of postnatal exposure to caffeine on the pattern of adenosine A1 receptor distribution in respiration-related nuclei of the rat brainstem

Caffeine, which belongs to the methylxantine family of compounds, is commonly ingested in a range of beverages such as coffee, tea, and cola drinks. It is also used therapeutically and is frequently employed in the treatment of respiratory disturbances in human neonates. The aim of the present work has been to examine the ontogeny of the adenosine A1 receptor system in the brainstem of the newborn rat following postnatal treatment with caffeine to mimic the therapeutic administration of caffeine to premature human infants. The effect of this postnatal exposure to caffeine on the gradual appearance of adenosine A1 receptors was analysed by determining immunohistochemically the distribution of the receptors. The main difference between control animals and animals exposed to caffeine was the transient increase (only at postnatal day 6) in the number of immunopositive neurons in two brainstem areas, the ventrolateral medulla and the rostral dorsolateral pons, in caffeine-treated rat pups, or more specifically, the parabrachial and Kölliker-Fuse nuclei, both of which are classically associated with respiratory control. With previous research highlighting the important role played by the rostral pons in respiratory modulation by the adenosine A1 receptor system, it is thus possible that postnatal exposure to caffeine modulates the ontogeny of the adenosine A1 receptor network. This could imply that the role of caffeine to decrease the incidence of neonatal respiratory disturbances may be due to the earlier than normal development of the adenosinergic system in the brain.

Caffeine in the milk prevents respiratory disorders caused by in utero caffeine exposure in rats

Consequences of postnatal caffeine exposure by the milk on ponto-medullary respiratory disturbances observed following an in utero caffeine exposure were analysed. Ponto-medullary-spinal cord preparations from newborn rats exposed to caffeine during gestation but not after the birth display an increase in respiratory frequency and an exaggeration of the hypoxic respiratory depression compared to not treated preparations. These data suggest that tachypneic and apneic episodes encountered in human newborns whose mother consumed caffeine during pregnancy are due in large part to central effect of caffeine at the ponto-medullary level. Both baseline respiratory frequency increase and emphasis of hypoxic respiratory depression are not encountered if rat dams consumed caffeine during nursing. Our hypothesis is that newborn rats exposed to caffeine during gestation but not after the birth would be in withdrawal situation whereas, when caffeine is present in drinking fluid of lactating dams, it goes down the milk and is able to prevent ponto-medullary respiratory disturbances.

Chronic caffeine or theophylline intake during pregnancy inhibits A1 receptor function in the rat brain

The aim of this work was to study whether caffeine or theophylline chronically consumed during pregnancy affect inhibitory adenylyl cyclase pathway mediated by adenosine, in rat brain of both mothers and full-term fetuses. Immunoblotting analysis revealed a significant decrease in alphaGi(1,2) subunit level (27-29% in mothers, 15-18% in fetuses), associated with a significant increase in the mRNA level coding alphaGi(1) in both maternal and fetal rat brain (12-22%) after methylxanthine intake. No significant differences in alphaGi(3) level were detected in any case. On the other hand, forskolin- and forskolin plus guanosine-5'-O(3-thiotriphosphate) tetralithium salt-stimulated adenylyl cyclase activity was significantly decreased (30-36%) in maternal brain. Moreover, adenylyl cyclase inhibition elicited by N(6)-cyclohexyladenosine, specific adenosine A(1) receptor agonist, was also significantly decreased in caffeine- (40.5%) and theophylline- (55.0%) treated mothers, suggesting a desensitization of adenosine A(1) receptor/adenylyl cyclase pathway in maternal brain. However, no significant differences were detected in fetal brain between control and treated animals. Therefore, caffeine or theophylline chronic intake during pregnancy differently modulates inhibitory adenylyl cyclase pathway mediated by adenosine in maternal and fetal brain causing a loss of the system responsiveness only in maternal brain but down-regulating Gi(1) protein in both mother and fetus brain.

Involvement of adenosinergic A1 systems in the occurrence of respiratory perturbations encountered in newborns following an in utero caffeine exposure. a study on brainstem–spinal cord preparations isolated from newborn rats

Involvement of adenosinergic A1 systems in the occurrence of respiratory perturbations encountered in newborns following an in utero caffeine exposure has been investigated on pontomedullary-spinal cord, caudal pons-medullary-spinal cord and medullary-spinal cord preparations isolated from newborn rats. According to the drinking fluid of dams (tap water or 0.02% caffeine), two groups of preparations were distinguished, no-caffeine and caffeine. In the no-caffeine group, adenosine A1 receptor activation induces a decrease in respiratory frequency (Rf) in caudal pons-medullary-spinal cord and medullary-spinal cord preparations whereas, in presence of the rostral pons, an increase is observed. A parallel Fos detection indicates that this discrepancy may be due to the excitatory action of the medial parabrachial nucleus at the rostral pontine level that surpasses inhibitory influence of the adenosine A1 receptor activation at the medullary level particularly in the ventrolateral reticular nucleus of the medulla. In caffeine group, an increase in the baseline Rf in presence of the pons and no change in medullary-spinal cord preparations have been observed. Depending on Fos detection, we assume that the medial parabrachial nucleus is the main region involved in the exaggeration of Rf. Moreover, adenosine A1 receptor activation was modified by in utero caffeine exposure with an overcharge of the Rf increase in pontomedullary-spinal cord preparations and an exaggeration of the Rf decrease in medullary-spinal cord preparations. Based on Fos detection, we link the overcharge in Rf of pontomedullary spinal cord preparations to an increase in the medial parabrachial nucleus neuronal activity. Similarly, exaggeration of Rf decrease observed without the pons is linked with a decrease in activity of the ventrolateral reticular neurons. This study brings evidence for the involvement of adenosinergic A1 systems in the occurrence of respiratory perturbations in newborns following in utero caffeine exposure and the importance of rostral pons in the adenosinergic A1 modulation of the respiratory control.

Consequences of in utero caffeine exposure on respiratory output in normoxic and hypoxic conditions and related changes of Fos expression: a study on brainstem-spinal cord preparations isolated from newborn rats

Several aspects of the central regulation of respiratory control have been investigated on brainstem-spinal cord preparations isolated from newborn rats whose dam was given 0.02% caffeine in water as drinking fluid during the whole period of pregnancy. Analysis of the central respiratory drive estimated by the recording of C4 ventral root activity was correlated to Fos ponto-medullary expression. Under normoxic conditions, preparations obtained from the caffeine-treated group of animals displayed a higher respiratory frequency than observed in the control group (9.2 +/- 0.5 versus 7.2 +/- 0.6 burst/min). A parallel Fos detection tends to indicate that the changes of the respiratory rhythm may be due to a decrease in neuronal activity of medullary structures such as the ventrolateral subdivision of the solitary tract, the area postrema, and the nucleus raphe obscurus. Under hypoxic conditions, the preparations displayed a typical hypoxic respiratory depression associated with changes in the medullary Fos expression pattern. In addition, the hypoxic respiratory depression is clearly emphasized after in utero exposure to caffeine and coincides with an increased Fos expression in the area postrema and nucleus raphe obscurus, two structures in which it is not increased in the absence of caffeine. Taken together, these results support the idea that in utero caffeine exposure could affect central respiratory control.

A review of the literature relating caffeine consumption by women to their risk of reproductive hazards

From this detailed review of the literature, several conclusions can be drawn: (a) An association between caffeine consumption and a reproductive hazard is more likely to be seen in lower-quality studies than in studies that come closer to approximating the ideal. This is especially evident for "lower" birthweight and congenital anomalies. (b) The association between caffeine consumption and spontaneous abortion may well reflect the Stein-Susser epiphenomenon (women with prominent nausea tend to reduce caffeine consumption and nausea appears to be a marker of good implantation, perhaps reflecting a favorable balance of hormones produced by a healthy placenta). (c) The claim that caffeine consumption by women delays conception has not been followed by convincing support. (d) Reproductive hazards associated with cigarette smoking tend to be associated with caffeine/coffee consumption. Sometimes this appears to be a consequence of residual confounding associated with inadequate adjustment for cigarette smoking, which is over-represented among those who drink the most coffee/caffeine. Sometimes this reflects the tendency of women to underreport socially undesirable behaviors (e.g. smoking) while accurately reporting socially neutral behaviors (e.g. coffee and caffeine consumption). Thus, it seems reasonable to conclude that no convincing evidence has been presented to show that caffeine consumption increases the risk of any reproductive adversity.

Adenosine A1 receptor down-regulation in mothers and fetal brain after caffeine and theophylline treatments to pregnant rats

Pregnant rats were treated daily with 1 g/L of caffeine or theophylline in their drinking water during pregnancy and the effect of these methylxanthines on adenosine A1 receptor was assayed using binding and reverse transcription polymerase chain reaction (RT-PCR) assays in brains from both mothers and full-term fetuses. In plasma membranes from pregnant rat brain, caffeine and theophylline caused a significant decrease in total receptor numbers, of the same order in both cases (30%), with no significant changes on receptor affinity. The effect of these adenosine receptor antagonists on plasma membranes from fetal brains was more marked, being detected at approximately 50% of the total receptors detected in control conditions. However, in this tissue, a significant increase in the receptor affinity, of the same order in both cases, was also detected after antagonist administration. No significant variation on the potency of caffeine and theophylline as antagonists was detected after treatments in mothers; however, higher affinities were detected in fetuses. A decrease in the total receptor numbers in fetal brain was associated with an increase in the mRNA coding A1 receptor, as determined by RT-PCR assays, not having detected any mRNA difference in maternal brain. No variation in the levels of mRNA coding A2A receptor was detected in any case. These results suggest that maternal caffeine or theophylline intake modulates adenosine A1 receptor, causing a down-regulation of adenosine A1 receptor in brain in both mothers and fetuses.

Distinct pharmacological mechanisms leading to c-fos gene expression in the fetal suprachiasmatic nucleus

Maternal treatment with cocaine or a D1-dopamine receptor agonist induces c-fos gene expression in the fetal suprachiasmatic nuclei (SCN). Other treatments that induce c-fos expression in the fetal SCN include caffeine and nicotine. In the current article, the authors assessed whether these different pharmacological treatments activate c-fos expression by a common neurochemical mechanism. The results indicate the presence of at least two distinct pharmacological pathways to c-fos expression in the fetal rat SCN. Previous studies demonstrate that prenatal activation of dopamine receptors affects the developing circadian system. The present work shows that stimulant drugs influence the fetal brain through multiple transmitter systems and further suggests that there may be multiple pathways leading to entrainment of the fetal biological clock.

Effects of discontinuing coffee intake on iron deficient Guatemalan toddlers' cognitive development and sleep

Coffee is commonly given daily to toddlers in Guatemala. Possible negative effects of coffee ingestion on cognitive development and sleep patterns were assessed in 132 children 12-24 months of age who had received coffee for > 2 months and were iron deficient on at least one indicator. Children were stratified by initial hemoglobin (A= anemic, Hgb < 10.5 g/dl; NA = 'non-anemic', Hgb > or = 10.5 g/dl) and were randomly assigned to an experimental group (S = substitute consisting of sugar and coloring), and a control group (C = continuation of coffee) (42 C-NA; 53 S-NA; 18 C-A; and 19 S-A). Anemic children were provided Fe supplements for 2-3 months. Compliance was assessed every 2 weeks. After 5 months, testers masked to treatment group and anemia evaluated children with the Bayley Scales of Infant Development II in a central location. Scores were the Mental Development Index (MDI), the Psychomotor Development Index (PDI), and scales from the Behavior Rating Scale (BRS). The child's sleep in the previous 24 h was assessed with a set of standardized sleep questions to the care giver on the first visit and every 2 weeks thereafter. No significant effects of treatment on test scores or BRS ratings were found. In the 24 h period reported on at the final visit, children in the Substitute group slept more during the night and overall (night plus naps) than children in the Coffee group, a difference not found at the first visit. No differences were found in sleep difficulty or number of times waking at night. Women's reported coffee intake per day during pregnancy was associated with lower BRS ratings, even after controlling for SES and child age. The effects of postnatal coffee ingestion in Guatemala were seen for sleep duration, but not for cognitive development. Prenatal coffee ingestion was negatively associated with Behavior Rating Scales and should be investigated further.

Effects of coffee consumption on iron, zinc and copper status in nonpregnant and pregnant Sprague-Dawley rats

To investigate the influence of coffee consumption on iron, zinc and copper status, 64 Sprague-Dawley female rats were assigned to four treatment groups: nonpregnant-given coffee, nonpregnant-given water, pregnant-given coffee and pregnant-given water. The coffee groups received a freeze-dried coffee solution (1.1% w/v) as the sole source of liquids during the 18-day study period; all groups were provided a purified diet marginal in iron ad libitum. On day 18 (of gestation in the pregnant rats), rats were intubated with 0.033 MBq59Fe after an 8 h fast and killed 4, 8, 12 or 24 h post-gavage. Fluid intake was significantly lower in the coffee groups. Coffee did not affect food consumption, weight gain, hemoglobin or hematocrit in either pregnant or nonpregnant rats. In nonpregnant rats, the percentage of 59Fe was lower in plasma and higher in the spleen and erythrocytes in the coffee group than in controls; in pregnant rats the coffee group had a higher percentage of 59Fe in the stomach (at 4 h only), blood, spleen and bone than controls. There were no significant effects of coffee on tissue concentrations of Fe, Zn or Cu in the nonpregnant group, but pregnant rats given coffee had high concentrations of Fe in the liver, bone and placenta, and low placenta Zn concentrations compared to controls. In fetuses, there were trends towards lower weight, length and percentage 59Fe, but higher liver Fe, in the coffee group than in the controls. The results suggest that coffee intake leads to (a) increased attempts at erythropoeisis, an indication of iron deficiency, in both nonpregnant and pregnant rats, and (b) impaired placental Fe transport.

A randomized intervention study of the effects of discontinuing coffee intake on growth and morbidity of iron-deficient Guatemalan toddlers

Coffee is widely consumed by children in Guatemala. To evaluate whether coffee has an adverse effect on growth or morbidity, 160 children 12-24 mo of age who had received coffee for > or = 2 mo and had at least one indicator of iron deficiency were stratified by initial hemoglobin (Hb) (A = anemic vs. NA = "nonanemic", i.e., Hb > or = 105 g/L) and randomly assigned to a control (C = continuation of coffee) or intervention group (S = provided with a substitute consisting of sugar and coloring) for 5 mo. Anemic children were provided iron supplements for 2-3 mo. Hematological and anthropometric measurements were made before and after the intervention, and dietary and morbidity data were collected every 2 wk. A total of 139 children completed the intervention: 45 C-NA, 56 S-NA, 19 C-A and 19 S-A. Compliance with the intervention was good: median coffee intake was 127 mL/d in group C vs. 3 mL/d in group S (P = 0.0001). There were no significant differences between C vs. S groups in food intake before or after the intervention. In the total sample, there was no effect of the intervention on weight or length gain. However, in children initially consuming more than 100 mL/d of coffee (n = 96), length gain was 22% greater in the S vs. the C group (P = 0.07), and weight gain was 46% greater in the S-A vs. the C-A group (P < 0.05; NS in the NA groups). Total illness prevalence (particularly respiratory illness) was significantly lower in the S-NA vs. the C-NA group (P < 0.05), but somewhat higher in the S-A vs. the C-A group (P = 0.09). Morbidity differences did not explain the effect of the intervention on growth. These results indicate a modest increase in growth associated with discontinuation of coffee consumption by toddlers with initial intakes >100 mL/d.

Autism, Asperger's syndrome and the Crick-Mitchison theory of the biological function of REM sleep

Autism, Asperger's syndrome and other autistic syndromes are developmental brain disorders that cause serious impairments in communication, social interaction, empathy, mood and play. In addition to such deficits, the autistic syndromes involve pathologically high levels of repetitive, stereotypic, ritualistic, compulsive or obsessive behavior, together with extreme resistance to change. According to the Crick-Mitchison theory of the biological function of rapid eye movement sleep, normal brain development in the fetus and infant depends on undisrupted function of a 'reverse learning' mechanism during rapid eye movement sleep. Could abnormalities in this hypothetical reverse learning during rapid eye movement sleep in the fetus explain some aspects of the autistic syndromes? Does the Crick-Mitchison theory suggest if a drug could interfere with rapid eye movement sleep and cross the placental barrier, then that drug might cause developmental brain disorders in the fetus? Should all pregnant women completely avoid caffeine or any agent that might disrupt serotonergic or cholinergic systems?