Sources of caffeine: 1. Caffeine is not only found in coffee, but also in a variety of foods and beverages (including tea, chocolate, cocoa products, cola, milk tea), and is also added to some soft drinks and most “energy” drinks. Caffeine is also found in some prescription and over-the-counter medications, such as cold and flu medications, allergy and headache treatments, diet pills, diuretics, and stimulants. 3, Nowadays, caffeine is increasingly found as an additive in snacks, sports supplements, and dietary supplements. Second, the effects of caffeine intake during pregnancy 1, the fetus: after pregnancy, the maternal caffeine metabolism is significantly weakened. Caffeine and its metabolites can easily cross the placenta and can be detected in the amniotic fluid and fetal blood at high levels. Higher maternal plasma caffeine levels appear to be associated with prolonged fetal wakefulness, increased fetal heart rate variability, decreased basal fetal heart rate, increased fetal respiratory activity, and inconsistent effects on fetal and placental blood flow. 2. Spontaneous abortion: The intake of caffeinated beverages at levels less than or equal to 5-6 mg/(kg-d) during pregnancy does not increase the risk of spontaneous abortion. Although some animal studies have found that higher caffeine intake slightly increases this risk, even a woman consuming 10 cups of coffee (about 1000mg of caffeine) in 8-10 hours does not reach this harmful level. 3. Congenital anomalies: Caffeine intake in the maternal diet slightly increases the risk of congenital limb defects, NTDs, and absent/microtia ears, esophageal atresia, small bowel atresia, and premature closure of cranial sutures. Maximum caffeine intake (300 mg/d or more) was associated with anorectal atresia. There is also no evidence of increased risk for cardiovascular malformations, orofacial clefts, bilateral renal agenesis or hypoplasia, diaphragmatic hernia, umbilical bulge, and abdominal clefts. 4, preterm birth: A systematic evaluation meta-analysis in 2010 included 15 cohort studies and 7 case-control studies and did not find a significant association between maternal caffeine intake at any time during pregnancy and preterm birth. 5, Gestational diabetes: Moderate pre-pregnancy coffee intake appears to prevent the development of gestational diabetes. 6, neonatal withdrawal: Several case reports have reported neonatal caffeine withdrawal symptoms, including irritability, convulsions and vomiting. These symptoms begin immediately after birth and can subside within 84 hours without intervention. All such cases have been associated with chronic high maternal caffeine intake. There is no information on withdrawal symptoms in newborns born to mothers who consumed less than 6 cups of caffeinated beverages per day. III. Recommendations for drinking coffee during pregnancy 1. Drinking coffee after pregnancy is not recommended. 2. Due to limitations and inconsistencies in the available data, we recommend that women who are preparing for pregnancy, are pregnant or breastfeeding limit their caffeine intake to less than 200-300 mg/d. 3, A standard cup of coffee contains 100mg of caffeine;, analysis of different coffees from different coffee shops found that the caffeine content varied between 72-130mg/cup. In the case of strong coffee, the caffeine content was 200-322mg/cup.