What Should I Avoid During My First Trimester?

During the first trimester of pregnancy, there are many things you should avoid to stay healthy and protect your baby. Lifestyle habits to stop or avoid during pregnancy include smoking, drinking alcohol, gaining too much weight, consuming too much caffeine, eating certain foods like raw or undercooked meat and eggs, raw sprouts, some seafood, and others.

The first trimester of pregnancy (the first three months) is when a fertilized egg divides rapidly into layers of cells and implants in the wall of the uterus. Those layers of cells become an embryo, and by six weeks, a heartbeat can be detected. By the end of the first trimester (the end of week 12) the baby’s bones, muscles, and organs have formed and it is now considered a fetus.

The baby grows fastest during the first trimester. By the end of the first trimester, the fetus can weigh about 0.5 to 1 ounce and measure an average of 3 to 4 inches in length.

The first trimester is also when pregnancy loss (miscarriage) can happen. This occurs in about 10% of pregnancies. 

Because of the rapidly developing baby as well as the risk of miscarriage, during the first trimester women are advised to avoid a number of activities and foods. 

• Avoid smoking and e-cigarettes
  • A woman shouldn’t smoke at any time during her pregnancy so once a woman finds out she is pregnant she should talk to her doctor about ways to quit the habit
  • Babies born to mothers who smoke are at increased risk for birth defects 
  • E-cigarettes are also not safe during pregnancy because the nicotine can damage a developing baby’s brain and lungs
• Avoid alcohol
  • There is no amount of alcohol that is considered safe to drink during pregnancy
  • Drinking during the first trimester can cause birth defects, lead to miscarriage and stillbirth, and cause behavioral and intellectual disabilities known as Fetal Alcohol Spectrum Disorders (FASDs)
• Avoid raw or undercooked meat and eggs
  • Raw or undercooked meat and eggs carry the risk of contracting listeriosis and toxoplasmosis, which can lead to serious and life-threatening illnesses, severe birth defects, and miscarriage
• Avoid raw sprouts 
  • These can contain E. coli and Salmonella
• Avoid certain seafood
  • Mackerel and tilefish have a high mercury content
• Avoid unpasteurized dairy products and unpasteurized juices
  • This includes soft cheeses such as feta, Brie, and goat cheese 
  • These may contain bacteria such as listeria
• Avoid processed meats such as hot dogs and deli meats
  • These can also contain listeria 
  • They also contain nitrates and nitrites
• Avoid too much caffeine
  • Some caffeine is ok: about 200 mg (2 cups of coffee)
  • Caffeine can cross the placenta and affect a baby’s heart rate
• Avoid gaining too much weight
  • Pregnant women do not have to “eat for two” during the first trimester (women usually need more calories during the second and third trimesters, but not necessarily during the first)
  • Women who gain too much weight during pregnancy put their child at greater risk for obesity later in life 
• Avoid saunas, hot tubs, whirlpools, and steam rooms
  • These places put a pregnant woman at risk of overheating, dehydration, and fainting 
  • A significant rise in the mother’s core temperature could affect her baby’s development, especially during the first trimester 
  • Some research has found that the risk of miscarriage may double if a pregnant woman uses one of these during the first trimester
• Avoid massage and acupuncture 
  • These therapies are generally safe during pregnancy but a pregnant woman’s abdomen should not be massaged during the first trimester
  • Acupuncture as well is generally safe during pregnancy, but certain acupuncture points should be avoided 
  • Women seeking acupuncture should make sure the acupuncturist is trained in treating pregnant women
• Avoid cleaning the cat’s litter box
  • A parasite found in feline waste called Toxoplasma gondii can cause miscarriage or stillbirth, or serious problems in babies born with the parasite
• Avoid certain cleaning products
  • Check the labels of cleaning products to make sure there are no warnings for pregnant women
  • Some mothballs and toilet fresheners have a chemical called naphthalene that can damage blood cells
• Avoid fake tans
  • These are generally safe for use during pregnancy, but they can cause an allergic reaction
  • Hormone levels during pregnancy make the skin more sensitive and can make a woman more prone to allergic reactions
  • Do not use tanning pills or tanning injections