While I don’t like making a habit of telling pregnant ladies what they cannot eat, there are a few things that I should point out from a food safety, pregnancy health, and your unborn child’s long-term health perspective.
High-Risk Foods + Food Borne Illness
Foods potentially contaminated with salmonella and listeria can be highly dangerous. Infection with salmonella may cause nausea, vomiting, abdominal cramps, diarrhea, fever, or headaches. In rare cases, salmonellosis may cause miscarriage. Similarly, listeriosis can produce mild symptoms, including fever, muscle aches and pains, headache, diarrhea, nausea, and even a cold or cough. If transmitted to your unborn baby, listeriosis can cause premature labor or stillbirth.
Fish in Moderation
Fish is an excellent source of omega 3 fatty acids and DHA, which are essential to support the development of your baby's nervous system, brain, and eyes. The consumption of fish should be limited; however, to 2-3 serves per week because of mercury contamination. Mercury is a neurotoxin and accumulates in the body when consumed in excess. Mercury can cause damage to your unborn baby’s brain and nervous system. Excessive exposure to mercury in utero can have long term impacts, including developmental delay.1
Food + Beverages that Contain Traces of BPA and Phthalates
BPA (bisphenol A) usually isn't on prospective parents' radar until they have had their baby. At this time, you'll often notice everything from baby bottles to toys are labeled BPA free. By now, you are probably thinking, "what the heck is BPA?" or you've had to google it.
BPA is a plastic, a known endocrine disruptor, meaning it interferes with your hormonal system. It is also a reproductive toxicant, altering fertility. BPA is used for manufacturing polycarbonate plastics.2 You’ll find BPA in plastic water and soda bottles, linings of tinned foods, and coffee cups, coffee cup lids, plastic takeaway containers, plus more.
It not only reduces fertility in both males3 and females but also accumulates in the placenta, breast milk, and colostrum.2 BPA is thought to impact neurobehavioral development, contribute to obesity and early sexual maturation in females, though more studies are required.4
Phthalates are equally detrimental to reproductive health but also the long-term health of children when exposed in utero. Phthalates are what make plastic flexible. Similarly, phthalates impact healthy brain development. Two cross-sectional studies 4 have shown reduce intelligence and an increased prevalence of behavioral disorders and ADHD in school-aged children with high levels of phthalate exposure.
There are still significant gaps in the literature, but it's better to be safe than sorry. It's doesn't take a scientist to know that synthetic human-made things are generally harmful to health. Be sure to avoid plastic products or limit your use of them. It's going to be impossible to avoid altogether, but reducing your exposure will be highly beneficial for your fertility and the health of your baby.
Herbal teas seem like a great option when you are trying to eliminate excessive caffeine while pregnant, but many herbs are not considered safe to consume in pregnancy. Imported herbal remedies, including traditional Chinese and Ayurvedic herbs, can also be a source of heavy metals and environmental toxicants.
A 2019 systemic review titled “Herbal Medicinal Product Use During Pregnancy and the Postnatal Period” published in the Journal of Obstetrics & Gynecology,5 looked at a total of 47 herbal medicines which involved 1,067,071 female subjects who were with pregnancy or postnatal. The review showed significant adverse effects with chamomile, licorice, angelica sinensis, nettle leaf, and parsley. Adverse outcomes included congenital malformations, alterations in blood glucose, preterm labor, and birth. Raspberry leaf, a herb commonly given in the last trimester of pregnancy to help induce and shorten labor, actually increased the instance of cesarean section delivery. Milder symptoms such as heartburn, reflux, and abdominal discomfort were observed in women using ginger, a common anti-nausea remedy.
The safest teas, in my opinion, are good old black, green and white. Green and black tea do contain caffeine but far lower levels than coffee.
Exposure to Pesticides
Reducing your exposure to pesticides in pregnancy can improve pregnancy outcomes as well as minimize the risk of miscarriage.6 Organochlorine pesticides (OCPs) are toxic to the nerves, and elevated levels may store in various parts of the body including blood, amniotic fluid, and the placenta.7 High exposure to pesticides during pregnancy has also been suggested to contribute to attention deficit hyperactivity disorder (ADHD).8
Understandably, eating 100% organic is not achievable for everyone. I encourage you to focus on sourcing local produce as they often have lower pesticide residues. Washing your fruits and vegetables before consumption helps to remove away the excess residues but also reduces the risk of foodborne illnesses. When possible, purchase organic meats and dairy products as they too can contain traces of pesticides. Swapping animal proteins a few times a week, for plant-based proteins can also help to reduce your exposure. Consuming organic legumes and organic soy products are often much more affordable when compared to organic animal proteins.
While there is a bunch of food you should avoid and reduce during pregnancy, there are plenty of safer and just as nutritionally dense alternatives. If you're not sure what foods are the most nutritious and healthy to eat in pregnancy, you'll find plenty of ideas and further information in my ebook "A holistic guide to pregnancy and preconception." The good news is it's not forever; you can have sushi and a glass of bubbles once bub is born!
1. Vandermeersch, G. et al. Environmental contaminants of emerging concern in seafood--European database on contaminant levels. Environ. Res. 143, 29–45 (2015).
2. Ziv-Gal, A. & Flaws, J. A. Evidence for bisphenol A-induced female infertility: a review (2007–2016). Fertil. Steril. 106, 827–856 (2016).
3. Cariati, F. et al. “Bisphenol a: an emerging threat to male fertility”. Reprod. Biol. Endocrinol. 17, 6 (2019).
4. Prenatal Exposures to Environmental Chemicals and Children’s Neurodevelopment.pdf.
5. Muñoz Balbontín, Y., Stewart, D., Shetty, A., Fitton, C. A. & McLay, J. S. Herbal Medicinal Product Use During Pregnancy and the Postnatal Period. Obstet. Gynecol. 133, 920–932 (2019).
6. Sharara, F. I., Seifer, D. B. & Flaws, J. A. Environmental toxicants and female reproduction. Fertil. Steril.70, 613–622 (1998).
7. Triche, E. W. & Hossain, N. Environmental Factors Implicated in the Causation of Adverse Pregnancy Outcome. Semin. Perinatol. 31, 240–242 (2007).
8. Bouchard, M. F., Bellinger, D. C., Wright, R. O. & Weisskopf, M. G. Attention-Deficit/Hyperactivity Disorder and Urinary Metabolites of Organophosphate Pesticides. PEDIATRICS 125, e1270–e1277 (2010).