Caffeine suppresses the expression of the Bcl-2 mRNA in BeWo cell culture and rat placenta

Maternal chronic caffeine intake impairs fertility, placental vascularization and fetal development in mice

Caffeine is commonly consumed by pregnant women to avoid fatigue or as a habit. However, it is not clearly determined its side effects to the conceptuses. This study evaluated placental morphofunctional alterations after maternal chronic caffeine intake and the effects on fetal growth. Female Swiss mice received, via gavage, caffeine doses (either 60, 120 or 240 mg/kg/day) seven days before mating until gestational days-(GD) 11.5 or 17.5. Fetal biometrical parameters were assessed, and placentae were either submitted to histomorphometrical or molecular evaluation of angiogenesis (placental growth factor-1[PlGF-1]), apoptosis (Caspase-3) and proliferation (Ki-67) markers (evaluated in Swiss dams) and to intravital microscopy (evaluated in C57BL/6 dams). Caffeine exposed fetuses exhibited intrauterine growth restriction in a sex-dependent manner, with greater commitment of female fetuses (P < 0.05). In addition, placentae from dams that received 120 mg/kg/day showed less irrigation by maternal blood and greater development of fetal vasculature, characterized by higher number of larger vessels (P < 0.05). Although no effects on apoptosis (Caspase-3) and angiogenesis (PlGF-1) were observed, dams treated with 60 mg/kg/day showed greater placental cell proliferation (Ki-67 staining) at GD 11.5 (P < 0.05). The group treated with 240 mg/kg/day exhibited only one pregnant dam for each gestational age, suggesting that this high caffeine consumption may compromise fertility. Taken together, even in the doses currently ingested by many pregnant women, caffeine has detrimental effects on placental vasculature and fetal development in mice. Therefore, our results strongly suggest that caffeine consumption in human pregnancies greater than the recommended doses should be avoided.

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.

The impact of periconceptional maternal lifestyle on clinical features and biomarkers of placental development and function: a systematic review

BACKGROUND

Worldwide, placenta-related complications contribute to adverse pregnancy outcomes, such as pre-eclampsia, fetal growth restriction and preterm birth, with implications for the future health of mothers and offspring. The placenta develops in the periconception period and forms the interface between mother and embryo/fetus. An unhealthy periconceptional maternal lifestyle, such as smoking, alcohol and under- and over-nutrition, can detrimentally influence placental development and function.

OBJECTIVE AND RATIONALE

The impact of maternal lifestyle on placental health is largely unknown. Therefore, we aim to summarize the evidence of the impact of periconceptional maternal lifestyle on clinical features and biomarkers of placental development and function throughout pregnancy.

SEARCH METHODS

A comprehensive search in Medline, Embase, Pubmed, The Cochrane Library Web of Science and Google Scholar was conducted. The search strategy included keywords related to the maternal lifestyle, smoking, alcohol, caffeine, nutrition (including folic acid supplement intake) and body weight. For placental markers throughout pregnancy, keywords related to ultrasound imaging, serum biomarkers and histological characteristics were used. We included randomized controlled trials and observational studies published between January 2000 and March 2017 and restricted the analysis to singleton pregnancies and maternal periconceptional lifestyle. Methodological quality was scored using the ErasmusAGE tool. A protocol of this systematic review has been registered in PROSPERO International prospective register of systematic reviews (PROSPERO 2016:CRD42016045596).

OUTCOMES

Of 2593 unique citations found, 82 studies were included. The median quality score was 5 (range: 0-10). The findings revealed that maternal smoking was associated with lower first-trimester placental vascularization flow indices, higher second- and third-trimester resistance of the uterine and umbilical arteries and lower resistance of the middle cerebral artery. Although a negative impact of smoking on placental weight was expected, this was less clear. Alcohol use was associated with a lower placental weight. One study described higher second- and third-trimester placental growth factor (PlGF) levels after periconceptional alcohol use. None of the studies looked at caffeine intake. Adequate nutrition in the first trimester, periconceptional folic acid supplement intake and strong adherence to a Mediterranean diet, were all associated with a lower resistance of the uterine and umbilical arteries in the second and third trimester. A low caloric intake resulted in a lower placental weight, length, breadth, thickness, area and volume. Higher maternal body weight was associated with a larger placenta measured by ultrasound in the second and third trimester of pregnancy or weighed at birth. In addition, higher maternal body weight was associated with decreased PlGF-levels.

WIDER IMPLICATIONS

Evidence of the impact of periconceptional maternal lifestyle on placental health was demonstrated. However, due to poorly defined lifestyle exposures and time windows of investigation, unstandardized measurements of placenta-related outcomes and small sample sizes of the included studies, a cautious interpretation of the effect estimates is indicated. We suggest that future research should focus more on physiological consequences of unhealthy lifestyle during the critical periconception window. Moreover, we foresee that new evidence will support the development of lifestyle interventions to improve the health of mothers and their offspring from the earliest moment in life.

Efeitos da ingestão de cafeína durante a gestação e a lactação sobre a pele de ratas e de filhotes e sua relação com as concentrações séricas do cortisol materno

O objetivo deste trabalho foi verificar os efeitos da ingestão materna de diferentes doses de cafeína durante a gestação e a lactação, na pele de ratas-mães e filhotes, bem como sua relação com as concentrações séricas do cortisol materno. Vinte e quatro ratas Wistar adultas foram distribuídas em quatro grupos, representados pelo controle e tratados, com cafeína nas doses de 25, 50 e 100mg/kg. Os grupos tratados receberam cafeína por sonda orogástrica durante toda a gestação e a lactação. O controle recebeu água destilada como placebo. Foram avaliados e quantificados os diferentes tipos de folículos pilosos e a espessura da epiderme. A técnica de imuno-histoquímica, com o uso do anticorpo anti-CDC47, foi utilizada para avaliar a proliferação celular da epiderme e dos folículos pilosos das mães. Na mãe, também foram mensurados os níveis séricos de cortisol pela técnica da quimioluminescência. Os dados foram submetidos à análise de variância com comparação das médias pelos testes Kruskal-Wallis e SNK. Nos grupos tratados com cafeína nas doses de 25 e 50mg/kg, tanto as mães quanto seus filhotes apresentaram hipotricose e/ou alopecia focal. Apesar de a frequência de alterações macroscópicas das mães ter sido superior a dos filhotes, nestes as lesões, quando presentes, foram difusas. A análise histológica demonstrou calcinose de folículos pilosos nas mães e nos filhotes. Mas a morfometria somente revelou diferença significativa no número de folículos pilosos das mães, bem como redução significativa da proliferação celular dos folículos pilosos do grupo tratado com 50mg/kg de cafeína. Os níveis de cortisol materno somente foram significativamente elevados no grupo tratado com 100mg/kg de cafeína. Conclui-se que a cafeína ingerida pelas ratas gestantes e lactantes pode causar lesões cutâneas tanto nas mães quanto nos filhotes, caracterizadas por hipotricose e/ou alopecia, independentemente dos níveis séricos do cortisol materno.

Role of p53-dependent placental apoptosis in the reproductive and developmental toxicities of caffeine in rodents

The aim of the present study was to evaluate the role of placental apoptosis in mediating the reproductive and developmental toxicity of caffeine in rodents. Female Kunming mice were treated with caffeine (60, 120 and 240 mg/kg per day) before and during pregnancy. The conception rate, maternal bodyweight gain, placental weight and indices of fetal developmental, including the rate of intrauterine growth retardation (IUGR; i.e. the actual number of fetuses exhibiting IUGR as a percentage of the total number of fetuses), were determined on gestational day (GD) 18. Female Wistar rats were treated with caffeine (20, 60 and 180 mg/kg per day) from GD11 to GD20. The IUGR rate, maternal plasma angiotensin (Ang) II and prolactin concentrations, placental pathology, expression of angiotensin AT(1) and AT(2) receptors and apoptosis-related proteins were measured on GD20. In mice, caffeine treatment dose-dependently reduced the total conception rate, delayed conception and decreased maternal bodyweight gain, placental weight, fetal bodyweight and fetal body and tail lengths, whereas the IUGR rate was increased. In rats, caffeine treatment dose-dependently decreased placental weight and fetal bodyweight and increased the IUGR rate. Abnormal placental structures and decreased maternal plasma prolactin concentrations were observed following 180 mg/kg per day caffeine treatment, which resulted in increases in renin-angiotensin system (RAS) activity, including maternal plasma AngII concentrations and placental AT(1B) and AT(2) receptor expression, and Bax and p53 expression, but decreases in placental Bcl-2 expression. On the basis of the results of the present study, it appears that caffeine ingestion has detrimental effects on the reproductive system and fetal development in rodents that are associated with chronic activation of the maternal and placental RAS, and induction of p53-dependent placental apoptosis.

The effects of prenatal exposure to methylxanthines

This review discusses epidemiology and laboratory studies on the effects of prenatal methylxanthine administration on some systems developing organisms. They are mainly absorbed from coffee, tea and cocoa products such as cola beverages and chocolate bars. Prenatal methylxanthine exposure can induce several unfavourables changes in the developing organism, which are persistent even in later phases of life. Based on results obtained from animal studies, the effect on embryogenesis is not only poorly understood but also controversial. It is therefore important to study interspecies differences as results may differ depending on animals used and administration methods.

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.

Expression of the endocannabinoid system in human first trimester placenta and its role in trophoblast proliferation

The endocannabinoid, anandamide, which binds to two major receptor proteins, the cannabinoid receptors (CBs) 1 and 2 (CB1 and CB2), has been shown to play a role in first trimester miscarriage possibly through impairment of the developing trophoblast. Although the precise molecular mechanisms underlying this are unknown, plasma anandamide levels are known to be regulated by the progesterone-induced enzyme, fatty acid amide hydrolase (FAAH). Here, we tested the hypothesis that temporal-spatial expression of FAAH, CB1, and CB2 is regulated during early pregnancy and that anandamide detrimentally alters trophoblast proliferation. Transcripts for CB1, CB2, and FAAH were demonstrated in first trimester trophoblast extracts with only the CB1 transcript being significantly regulated. The significant 4.7-fold increase in expression at wk 10 gestation was reduced to 8.9% of the peak value by wk 12. Transcripts for CB2 showed a similar pattern of expression but were not significantly induced. By contrast, FAAH transcript levels appeared to increase toward the end of the first trimester, but again did not reach significance. These observations were supported by immunohistochemical studies that demonstrated a similar pattern of expression at the protein level, with cellular localization for all three proteins concentrated within the syncytiotrophoblast layer. Anandamide also prevented BeWo trophoblast cell proliferation in a dose-dependent manner, with a 50-60% significant inhibition of cell proliferation with concentrations in excess of 3 mum. This effect was mediated through CB2. Together, these data provide insights into how elevated plasma anandamide levels increase the risk of first trimester miscarriage.

Coffee and fetal death: a cohort study with prospective data

The authors conducted a cohort study within the Danish National Birth Cohort to determine whether coffee consumption during pregnancy is associated with late fetal death (spontaneous abortion and stillbirth). A total of 88,482 pregnant women recruited from March 1996 to November 2002 participated in a comprehensive interview on coffee consumption and potentially confounding factors in pregnancy. Information on pregnancy outcome was obtained from the National Hospital Discharge Register and medical records. The authors detected 1,102 fetal deaths. High levels of coffee consumption were associated with an increased risk of fetal death. Relative to nonconsumers of coffee, the adjusted hazard ratios for fetal death associated with coffee consumption of 1/2-3, 4-7, and > or =8 cups of coffee per day were 1.03 (95% confidence interval (CI): 0.89, 1.19), 1.33 (95% CI: 1.08, 1.63), and 1.59 (95% CI: 1.19, 2.13), respectively. Reverse causation due to unrecognized fetal demise may explain the association between coffee intake and risk of fetal death prior to 20 completed weeks' gestation but not the association with fetal loss following 20 completed weeks' gestation. Consumption of coffee during pregnancy was associated with a higher risk of fetal death, especially losses occurring after 20 completed weeks of gestation.