A human pregnancy takes place over three trimesters, and each trimester is roughly 13 weeks. The first trimester begins with your last menstrual period and extends until you are 13 weeks pregnant. During this time, your developing baby is particularly sensitive to toxins and certain dietary factors, making nutrition very important.
Significance
The first trimester of pregnancy, explains Dr. Miriam Stoppard in her book "Conception, Pregnancy and Birth," is a sensitive time for a developing baby. Strangely enough, you are only truly pregnant for 11 of the first 13 weeks of your pregnancy---the first two weeks of the "pregnancy" take place between your last period and conception. Still, these weeks set the stage for a healthy pregnancy, and nutrition is important, just as it is during the remainder of your first trimester.
Features
Nutrition during the first trimester ensures that your system contains all the necessary nutrients to nourish a developing baby and none of the toxins that could adversely affect growth or cause miscarriage. Because embryos develop their organ systems during the first few weeks of pregnancy--organs are mostly developed by 8 weeks---they are especially susceptible to both toxins and vitamin or nutrient deficiencies during this time, explain Heidi Murkoff and Sharon Mazel in their book "What To Expect When You're Expecting."
Considerations
In addition to a healthy diet including carbohydrates, proteins, healthy fats---nontropical plant oils like olive oil---and plenty of fruits and vegetables, you should also include certain key vitamins in your early pregnancy nutrition plan. Explains Dr. Raymond Poliakin in his book "What You Didn't Think to Ask Your Obstetrician," folic acid is an important nutrient early in pregnancy because it promotes normal development of the neural tube, which later develops into the spinal cord and column. You should take folic acid supplements during the first trimester to ensure proper quantities.
Misconceptions
Many women think that pregnancy involves "eating for two," and happily clean not only their own plates but those of their eating companions as well. In fact, while pregnancy does require a little extra energy, your caloric requirements during pregnancy are nearly identical to those of nonpregnant women, notes Poliakin. It's easy to gain too much weight early in pregnancy by overeating, which puts both you and your baby at risk for obesity and other complications.
Expert Insight
In addition to watching what you eat, you should be careful to avoid certain toxins in your first trimester. Alcohol, for instance, leads to birth defects and increases the risk for preterm labor and low birth weight, explains Stoppard. Caffeine may increase the risk of miscarriage, particularly during the first trimester, and you should aim to limit caffeine consumption to approximately 200 to 300 mg per day at most. Undercooked meats and uncooked fish can harbor bacteria, and you should avoid them during pregnancy as well.
References
- "Conception, Pregnancy and Birth"; Miriam Stoppard, M.D.; 2008
- "What to Expect When You're Expecting"; Heidi Murkoff and Sharon Mazel; 2008
- "What You Didn't Think to Ask Your Obstetrician"; Raymond Poliakin, M.D.; 2007
