Publicação
Perinatal consequences of maternal caffeine intake during pregnancy: how much is safe? - A systematic review and meta- analysis
| Resumo: | Introduction: Caffeine is a widely consumed stimulant that can be found in a range of beverages such as coffee, tea, chocolate, and even some medicine, which makes it easily ingested in considerable amounts during pregnancy. This stimulant can freely transfer across all biological membranes, including the blood–placental barrier. The main enzyme involved in caffeine metabolism (cytochrome P450 1A2) is absent in both the placenta and the fetus. Therefore, the fetus depends on maternal caffeine metabolism. However, throughout gestation, there is a delayed maternal clearance of caffeine, and the rate of caffeine metabolism decreases progressively from the first to the third trimester. Consequently, the fetus is exposed to caffeine and its metabolites for a prolonged period, which can lead to caffeine accumulation in fetal tissues and leaves neonates at risk of adverse outcomes.Several authors of observational studies established an association between maternal caffeine intake and adverse fetal, neonatal, and pregnancy outcomes. Nevertheless, conflicting results found in the literature make it difficult for health professionals to advise pregnant women about avoiding caffeine during pregnancy, since the precise level of intake above which the risk increases, remains unknown.Aims: We aimed to systematically review the published literature on the effects of caffeine intake by mother on fetal, neonatal and pregnancy outcomes with the purpose to establish a safe quantity of caffeine that could be ingested during gestational period, without increasing the risk of adverse outcomes.Methods and results: We systematically searched PubMed, EMBASE, and Web of Science on 27, 29, and 31 of January, respectively. The search was limited by language (English and Portuguese), type of subjects (human) and in time (since 1990, in the last 30 years). We searched for articles that related maternal caffeine consumption with fetal, neonatal and pregnancy outcomes under analyses (spontaneous abortion, stillbirth, low birth weight, intrauterine growth restriction, small for gestational age, preterm birth, congenital anomalies, SIDS and gestational diabetes mellitus). A total of 57 studies were included in the review; only 46 were included in the meta-analyses. We conducted a meta-analysis using a random-effects model (heterogeneity evaluated by Higgins e Thompson I2) and selected as a final result the model that separated further cases and control groups, being the one who presented a lower p-value. According to the results, the absence of caffeine consumption seems to increase the chance of occurrence of events such as spontaneous abortion (5 times), intrauterine growth restriction (4 times), small for gestational age (11 times), preterm birth (6 times) or congenital anomalies (43 times); therefore, we can infer that caffeine consumption may have a protective effect on the occurrence of those events in pregnant women and newborns. Additionally, we verified that a maternal caffeine intake higher than 200 mg/day seems to increase the risk of intrauterine growth restriction and congenital anomalies. A caffeine consumption above 300 mg/day also appears to enhance spontaneous abortion and small for gestational age events. Caffeine intake beyond 400 mg/day seems to increase the risk of low birth weight and preterm birth by more than ten times (10. 061 and 12. 825 on average, respectively).Conclusion: According to these results, the ingestion of caffeine until 200 mg/day is secure and protective.KEYWORDS: CAFFEINE; COFFEE; PREGNANCY; PERINATAL OUTCOME; MATERNAL CONSUMPTION; |
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| Autores principais: | Bessa, Margarida Miguel de Paredes |
| Assunto: | CAFFEINE COFFEE PREGNANCY PERINATAL OUTCOME MATERNAL CONSUMPTION CAFEÍNA CAFÉ GRAVIDEZ CONSUMO MATERNO CONSEQUÊNCIAS PERINATAIS |
| Ano: | 2020 |
| País: | Portugal |
| Tipo de documento: | dissertação de mestrado |
| Tipo de acesso: | acesso embargado |
| Instituição associada: | Universidade de Coimbra |
| Idioma: | inglês |
| Origem: | Estudo Geral - Universidade de Coimbra |
| Resumo: | Introduction: Caffeine is a widely consumed stimulant that can be found in a range of beverages such as coffee, tea, chocolate, and even some medicine, which makes it easily ingested in considerable amounts during pregnancy. This stimulant can freely transfer across all biological membranes, including the blood–placental barrier. The main enzyme involved in caffeine metabolism (cytochrome P450 1A2) is absent in both the placenta and the fetus. Therefore, the fetus depends on maternal caffeine metabolism. However, throughout gestation, there is a delayed maternal clearance of caffeine, and the rate of caffeine metabolism decreases progressively from the first to the third trimester. Consequently, the fetus is exposed to caffeine and its metabolites for a prolonged period, which can lead to caffeine accumulation in fetal tissues and leaves neonates at risk of adverse outcomes.Several authors of observational studies established an association between maternal caffeine intake and adverse fetal, neonatal, and pregnancy outcomes. Nevertheless, conflicting results found in the literature make it difficult for health professionals to advise pregnant women about avoiding caffeine during pregnancy, since the precise level of intake above which the risk increases, remains unknown.Aims: We aimed to systematically review the published literature on the effects of caffeine intake by mother on fetal, neonatal and pregnancy outcomes with the purpose to establish a safe quantity of caffeine that could be ingested during gestational period, without increasing the risk of adverse outcomes.Methods and results: We systematically searched PubMed, EMBASE, and Web of Science on 27, 29, and 31 of January, respectively. The search was limited by language (English and Portuguese), type of subjects (human) and in time (since 1990, in the last 30 years). We searched for articles that related maternal caffeine consumption with fetal, neonatal and pregnancy outcomes under analyses (spontaneous abortion, stillbirth, low birth weight, intrauterine growth restriction, small for gestational age, preterm birth, congenital anomalies, SIDS and gestational diabetes mellitus). A total of 57 studies were included in the review; only 46 were included in the meta-analyses. We conducted a meta-analysis using a random-effects model (heterogeneity evaluated by Higgins e Thompson I2) and selected as a final result the model that separated further cases and control groups, being the one who presented a lower p-value. According to the results, the absence of caffeine consumption seems to increase the chance of occurrence of events such as spontaneous abortion (5 times), intrauterine growth restriction (4 times), small for gestational age (11 times), preterm birth (6 times) or congenital anomalies (43 times); therefore, we can infer that caffeine consumption may have a protective effect on the occurrence of those events in pregnant women and newborns. Additionally, we verified that a maternal caffeine intake higher than 200 mg/day seems to increase the risk of intrauterine growth restriction and congenital anomalies. A caffeine consumption above 300 mg/day also appears to enhance spontaneous abortion and small for gestational age events. Caffeine intake beyond 400 mg/day seems to increase the risk of low birth weight and preterm birth by more than ten times (10. 061 and 12. 825 on average, respectively).Conclusion: According to these results, the ingestion of caffeine until 200 mg/day is secure and protective.KEYWORDS: CAFFEINE; COFFEE; PREGNANCY; PERINATAL OUTCOME; MATERNAL CONSUMPTION; |
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