Please note this information is not medical advice, and for advice on your specific needs you should always consult your medical practitioner.
Coffee, in moderation, can keep you awake and make you more alert. But if you’re pregnant, you need to watch your coffee drinking habits. Coffee contains caffeine, and caffeine can cause several pregnancy complications, studies warn [1].
It is estimated that in the USA, 70% of those who are pregnant continue to consume caffeine [1]. A daily consumption of more than 300-500mg caffeine was reported in some women [1].
Is caffeine bad for pregnant women?
Caffeine is considered harmful during pregnancy if consumed in higher doses. Upon consumption, caffeine is readily absorbed into the bloodstream and it is distributed throughout the body rapidly. Caffeine easily crosses the placental membrane and passes into the placenta and the brain of the fetus. The placenta nor the fetal brain contains enzymes necessary to metabolise caffeine, thus caffeine gets accumulated in the placenta and the fetal brain.
Studies confirm that the time taken to clear caffeine from the body is significantly longer for pregnant women than it is for non-pregnant women [2], [3].
Studies also report that caffeine may cause pregnancy complications including miscarriages [4] [5], stillbirth [6], and low birth weights [7]. One study also reported that consuming too much coffee during pregnancy can later translate into brain development issues for kids [8].
Apart from these pregnancy complications, some studies also conclude that high caffeine consumption can affect fertility by delaying conception [9].
Consuming high amounts of caffeine is also associated with increased blood pressure [10]. Caffeine is also known to be a diuretic and this can cause discomfort for some pregnant women. Caffeine can also interfere with the quality of sleep in some women, which may make them more exhausted in the long run.
How much caffeine is safe during pregnancy?
Royal Hospital for Women (Australia) and other health authorities recommend that pregnant women can safely consume less than 200mg of caffeine per day [11]. This is the equivalent of one cup of strong espresso coffee or 3 cups of instant coffee [11]. However, a research study recently published suggested that there is no safe level for caffeine consumption in pregnant women or women who are expecting to conceive [12]. This study warns that caffeine, even in moderate quantities, can result in miscarriage, stillbirth, low birth weight, childhood acute leukemia, childhood overweight and obesity [12].
Tips for limiting caffeine intake
If you enjoy a daily cup of coffee but you need to limit your caffeine intake, you can try switching your regular coffee with a decaffeinated coffee. Decaf coffees offer the same taste and aroma of coffee without the unwanted caffeine.
You should keep in mind that it's not only coffee that contains caffeine. Tea, chocolate, and cola drinks can also contain caffeine, so you need to be mindful of your consumption of these beverages as well. Some over-the-counter medications can also contain caffeine.
If you rely on caffeine for an energy boost and a kick of alertness, you can try swapping caffeine for exercise. Exercise is also known to boost the energy levels in the same way as caffeine does [13][14].
References:
[1] J. Qian, Q. Chen, S. M. Ward, E. Duan, and Y. Zhang, “Impacts of Caffeine during Pregnancy,” Trends Endocrinol. Metab., vol. 31, no. 3, pp. 218–227, 2020, doi: 10.1016/j.tem.2019.11.004. https://www.sciencedirect.com/science/article/abs/pii/S1043276019302267
[2] W. D. Parsons and J. G. Pelletier, “Delayed elimination of caffeine by women in the last 2 weeks of pregnancy,” Can. Med. Assoc. J., vol. 127, no. 5, pp. 377–380, 1982, Accessed: Apr. 07, 2021. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1861995/
[3] J. L. Brazier, J. Ritter, M. Berland, D. Khenfer, and G. Faucon, “Pharmacokinetics of caffeine during and after pregnancy,” Dev. Pharmacol. Ther., vol. 6, no. 5, pp. 315–322, 1983, doi: 10.1159/000457332. https://www.karger.com/Article/Abstract/457332
[4] A. J. Gaskins, J. W. Rich-Edwards, P. L. Williams, T. L. Toth, S. A. Missmer, and J. E. Chavarro, “Pre-pregnancy caffeine and caffeinated beverage intake and risk of spontaneous abortion,” Eur. J. Nutr., vol. 57, no. 1, pp. 107–117, Feb. 2018, doi: 10.1007/s00394-016-1301-2. https://link.springer.com/article/10.1007/s00394-016-1301-2
[5] X. Weng, R. Odouli, and D. K. Li, “Maternal caffeine consumption during pregnancy and the risk of miscarriage: a prospective cohort study,” Am. J. Obstet. Gynecol., vol. 198, no. 3, pp. 279.e1-279.e8, Mar. 2008, doi: 10.1016/j.ajog.2007.10.803. https://www.sciencedirect.com/science/article/abs/pii/S000293780702025X
[6] D. C. Greenwood et al., “Caffeine intake during pregnancy, late miscarriage and stillbirth,” Eur. J. Epidemiol., vol. 25, no. 4, pp. 275–280, Apr. 2010, doi: 10.1007/s10654-010-9443-7. https://link.springer.com/article/10.1007/s10654-010-9443-7
[7] CARE Study Group, “Maternal caffeine intake during pregnancy and risk of fetal growth restriction: A large prospective observational study,” BMJ, vol. 337, no. 7682, pp. 1334–1338, Dec. 2008, doi: 10.1136/bmj.a2332. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2577203/
[8] Z. P. Christensen, E. G. Freedman, and J. J. Foxe, “Caffeine exposure in utero is associated with structural brain alterations and deleterious neurocognitive outcomes in 9–10 year old children,” Neuropharmacology, vol. 186, Mar. 2021, doi: 10.1016/j.neuropharm.2021.108479. https://www.sciencedirect.com/science/article/abs/pii/S0028390821000332
[9] C. K. Stanton and R. H. Gray, “Effects of Caffeine Consumption on Delayed Conception,” Am. J. Epidemiol., vol. 142, no. 12, pp. 1322–1329, Dec. 1995, doi: 10.1093/oxfordjournals.aje.a117600. https://academic.oup.com/aje/article-abstract/142/12/1322/59709
[10] T. R. Hartley, B. H. Sung, G. A. Pincomb, T. L. Whitsett, M. F. Wilson, and W. R. Lovallo, “Hypertension risk status and effect of caffeine on blood pressure,” Hypertension, vol. 36, no. 1, pp. 137–141, 2000, doi: 10.1161/01.HYP.36.1.137. https://www.ahajournals.org/doi/full/10.1161/01.HYP.36.1.137
[11] “Caffeine and Pregnancy.” https://www.seslhd.health.nsw.gov.au/sites/default/files/migration/Mothersafe/documents/Caffeinenov27.pdf (accessed Apr. 18, 2021).
[12] Jack E. James, “Maternal caffeine consumption and pregnancy outcomes: a narrative review with implications for advice to mothers and mothers- to- be,” BMJ Evidence- Based Med., pp. 1–9, 2020, doi: 10.1136/bmjebm-2020-111432. https://ebm.bmj.com/content/early/2020/09/01/bmjebm-2020-111432
[13] “When Exercise Can Offer the Same Boost as Coffee (and When It Can’t).” https://lifehacker.com/when-exercise-can-offer-the-same-boost-as-coffee-and-w-1556556534 (accessed Apr. 07, 2021).
[14] “What Happened When I Replaced Coffee With 30 Seconds of Exercise.” https://www.thedailybeast.com/what-happened-when-i-replaced-coffee-with-30-seconds-of-exercise (accessed Apr. 07, 2021).