Increased caffeine consumption during pregnancy has been of main concern in regard to maternal nutrition and a hot topic of research in regard to the association with fetal pre-term birth and low birth weight. Previous studies found a correlation with women who consume caffeine at greater than 300 mg per day during pregnancy and babies born at 100-200g below the birth weights of babies from mothers who consumed little caffeine. In addition, other studies have found a correlation with caffeine and pre-term births. (Bech et al., 2007) Due to research focused on caffeine and pregnancy, the World Health Organization (WHO) recommended that women consume an intake of caffeine below 300mg/day during pregnancy. Other organizations, such as the American College of Obstetricians and Gynecologists and Norwegian Food Safety Authority recommend a maximum of 200 mg of caffeine. (Bacelis, 2013)
Caffeine is a chemical compound that is found in various drinks such as coffee, tea, energy drinks, as well as in chocolate. Caffeine is known to have biological effects such as neurological stimulation, increased release at catecholamine’s, increased heart rate, and increased smooth muscle relaxation. In addition, it reaches a peak level 30-60 minutes after consumption and it’s half-life occurs 2.5-4.5 hours after ingestion. (Etherton and Kochar, 1993) In addition, increased estrogen in pregnancy increases the half-life of caffeine to 7 hr-10.5hr during the last weeks of pregnancy. (Ware, 1995). Furthermore, caffeine has the ability to pass through the placenta to the fetus. The fetus does not express the enzymes needed in order to inactivate caffeine molecules and the metabolites formed from the breakdown of caffeine are stored in the fetal brain.(Andersson et al., 2004; Wilkinson and Pollard, 2004)
Studies have tried to obtain evidence linking caffeine to low birth weights; however, there are other factors associated with people who intake caffeine, such as smoking and alcohol. One study by Bech et al. (2007), measured the effect of caffeine on birth weight. The study used a population of Danish women who consumed at least three cups of coffee per day. The study found that a moderate decrease in caffeine during the second half of pregnancy had no significant effect on birth weight or length of pregnancy. Therefore, it can be suggested that caffeine does in fact have an effect on birth weight and gestation period. Another study conducted by Forteir et al. (1993) found that caffeine can influence a low birth weight through growth retardation. Growth retardation is diagnosed when an infant is less than 10th percentile for both sex and gestational age. In Forteir et al (1993), it was found that for each increase in average caffeine consumption per day, there was a correlation with an increase in growth retardation.
Overall, studies have linked caffeine with fetal development and gestation. There are known physiological effects of caffeine and these effects are increased during pregnancy; therefore, further research should focus on controlled studies in order to further confirm the correlation and provide more educational awareness to women considering getting pregnant.
The search engine that was used in order to find articles related to caffeine and pregnancy was Google Chrome. I initially used, “Pregnancy and caffeine pdf”, in order to obtain peer-reviewed articles. From that search engine, I was referred to PubMed articles. In addition, once in PubMed, I was able to find articles from the “related articles” section in PubMed.
Andersson H., Hallström H., Kihlman B.A. (2004). In Intake of caffeine and other methylxanthines during pregnancy and risk for adverse effects in pregnantwomen and their fetuses. Volume 2004. Copenhagen, Denmark: NordicCouncil of Ministers.
Bacelis, J., Nilsson, S., Grove, J., Mygre, R., Haugen, M., Meltzer, M., Alexander, J., Jacobsson,
B., Brantsaeter, A. (2013). Maternal caffeine intake during pregnancy isassociated with birth weight but not withgestational length: results from a largeprospective observational cohort study. BMC Medicine. 11:42.
Bech, B.H., Obel, C., Henriksen, T.B., Olsen, J. (2007). Effect of reducing caffeine intake on birth weight and lengthof gestation: randomised controlled trial. BMJ:1-6.
Etherton, G.M., Kochar, M.S. (1993). Coffee: Facts and Controversies. Arch Fam Medicine. March. 2(3):317:322.
Forteir I., Marcoux S., Beaulac-Baillargeon, L. (1993). Relation of caffeine intake during pregnancy to intrauterine growth retardation and preterm birth. American Journal of Epidemiology 1. 137(9):931-939.
Ware, K. (1995). Caffeine and Pregnancy Outcome. University of Los Angeles. Nutrition Bytes. 1(1).
Wilkinson J.M., Pollard I. (1993). Accumulation of theophylline, theobromine andparaxanthine in the fetal rat brain following a single oral dose ofcaffeine. Brain Res Dev Brain Res. 75:193-199.