For this reason, it’s a good idea to limit caffeine intake during pregnancy and speak with your doctor for specific recommendations. In small doses, caffeine can make you feel refreshed and focused. In large doses, caffeine can make you feel anxious and have difficulty sleeping. Caffeine is a stimulant, which means it increases activity in your brain and nervous system. It also increases the circulation of chemicals such as cortisol and adrenaline in the body.

http://newsnetwork.mayoclinic.org/discussion/energy-drinks-raise-resting-blood-pressure-with-effect-most-dramatic-in-those-not-used-to-caffeine-m/This difference is most likely caused by a small loss of antioxidants during the decaffeination process. Studies have suggested that more than 300 mg a day of caffeine, or the amount equal to around three cups of coffee, could lead to:

Drinkers who consume alcohol mixed with energy drinks are three times more likely to binge drink than drinkers who do not report mixing alcohol with energy drinks.One longitudinal study found that participants who increased their coffee intake by more than one cup a day over a 4-year period had a 1 percent lower risk of developing type 2 diabetes compared with people who did not change their intake. Song, F., Qureshi, A. A., & Han, J. (2012, July 1). Increased caffeine intake is associated with reduced risk of basal cell carcinoma of the skin. Cancer Research Much of the data collected on caffeine is observational in nature. There have been few randomized, controlled studies.

Some research suggests that caffeine may reduce muscle activity in the fallopian tubes, which carry eggs from the ovaries to the womb. a b Luo, Lin; Lane, Majella E. (July 2015). "Topical and transdermal delivery of caffeine". International Journal of Pharmaceutics. 490 (1–2): 155–164. doi: 10.1016/j.ijpharm.2015.05.050. PMID 26004004.Studies have also reported that people with a higher coffee consumption have a lower risk of Parkinson’s disease. Memory

However, it’s worth mentioning again that the research on regular coffee is way more extensive than what’s available for decaf. Summary: O’Keffe J, et al. (2013). Effects of habitual coffee consumption on cardiometabolic disease, cardiovascular health, and all-cause mortality. Otberg, Nina; Patzelt, Alexa; Rasulev, Utkur; Hagemeister, Timo; Linscheid, Michael; Sinkgraven, Ronald; Sterry, Wolfram; Lademann, Jürgen (April 2008). "The role of hair follicles in the percutaneous absorption of caffeine". British Journal of Clinical Pharmacology. 65 (4): 488–492. doi: 10.1111/j.1365-2125.2007.03065.x. ISSN 0306-5251. PMC 2291387. PMID 18070215.Bhupathiraju, S. N., Pan A., Manson, J. E., Willett, W. C., van Dam, R. M., & Hu, F. B. (2014, April 26). Changes in coffee intake and subsequent risk of type 2 diabetes: three large cohorts of US men and women [Abstract]. Diabetologia. 57(7),1346-54 Caffeine increases the release of acid in the stomach, sometimes leading to an upset stomach or heartburn. According to the National Institutes of Health (NIH), the weeks before pregnancy also count. Research shows that if both parents consume more than two caffeinated drinks a day in the weeks before they conceive, a loss of pregnancy may be more likely.