Your First Trimester Week by Week
Now that we’ve tackled the least fun aspect of early pregnancy, let’s travel through the first trimester week by week to see how your baby is growing and developing during the first 12 weeks of life in the womb.
For each week, I will briefly describe the key developmental processes that are occurring and suggest a “food of the week,” which you can incorporate into different dishes while continuing to eat a balanced diet. I have also listed some recipes for each week that you might try, as well as other suggestions for ways to easily incorporate the food of the week into your diet.
HOW OLD IS MY BABY?
Your baby’s age while in the womb can be counted in two ways: by conceptional
age or gestational age. Conceptional age is based on the day your baby was
conceived, while gestational age is based on the first day of your last menstrual
period. Both methods are a bit tricky.
Conceptional age may seem like the logical
way of counting your baby’s age, but many women don’t know exactly when they
got pregnant. Even if you’ve been tracking things like a detective, you still may
have no clue when your egg was fertilized, since a few days can pass between the
time of intercourse and fertilization. Sperm need some time to reach their
destination and do their job.
Gestational age, on the other hand, starts counting
your baby’s “age” before it actually exists; it considers your last period and the
days before you conceived as the beginning of pregnancy, which is also a bit
confusing. Here are nice rules of thumb for calculating either: If you know the
exact date of conception, add two weeks and you’ll get gestational age. If you
know the first day of your last period, subtract two weeks and you’ll get
To make it easier to understand, I will use conceptional age
when describing the different stages of pregnancy and include the gestational
age in parentheses next to each week’s heading.
(Gestational Week 3)
This is the germinal stage: fertilization and implantation.
The first week is when fertilization occurs, meaning that your egg and your partner’s sperm cell combine to produce a zygote with forty-six chromosomes. Your baby’s sex is denied at the moment of conception, depending on whether it receives an X (female) or a Y (male) chromosome from the father. The zygote travels to your uterus, rapidly dividing on its way (it is now a ball of cells called a blastocyst). Around day 7 following fertilization, the zygote implants in the lining of your uterus and begins to receive nutrients from your body.
It may be helpful to note that at this stage, the fertilized egg is thought
to be not very susceptible to toxic agents, such as drugs or alcohol. This
is not meant to be a green light to hit happy hour; if the trauma from a
toxin is severe enough, it can cause a termination of the pregnancy, even
though you may not even know you are pregnant at this time and may
not notice anything. If the baby survives, however, toxins are not thought
to cause abnormalities this early on. So if you did have a glass (or two) of
wine during this week (when most women don’t even know they are
pregnant), don’t sweat it.
Food of the Week: Lentils
Early on in pregnancy, folate is key, and lentils are simply packed with it. Also, they’re a good source of iron to start building up your stores from the very beginning. Lentils also contain ber, phosphorus, protein, vitamin B6, potassium, zinc, and copper, among other nutrients. A cup of cooked lentils (about 200 g) contains more than half of your daily folate requirement (about 360 mcg; you need 600 per day). Simple to prepare and easy to digest, lentils are wonderful in soup, salad, or a side dish.
Easy Seasoned Lentils
For a protein- and fiber-rich vegetarian entrée, try these lentils
spooned over baked potatoes or sweet potatoes. Double the
recipe for excellent leftovers, which can be used to fill wraps or
whole wheat pitas. Leftovers also freeze well for make-ahead
1¾ cups water
½ cup brown lentils
1 carrot, chopped
½ cup chopped tomatoes, fresh or canned and drained
1 cup chopped celery
¼ teaspoon each salt, onion powder, garlic powder, turmeric,
1 teaspoon hot sauce
1 teaspoon extra-virgin olive oil
Bring the water to a boil, then add the lentils, carrot, tomatoes,
and celery and reduce the heat to low. Cover and simmer for
Uncover and add the salt, onion powder, garlic powder,
turmeric, cinnamon, hot sauce, and oil. Stir and cook until the
liquid is absorbed, about 5 minutes. Serve warm.
(Gestational Week 4)
This is when cells begin to dierentiate.
Starting in week 2, the zygote is already implanted in your uterus and is actively developing, even though it’s so tiny that it would still not be visible to the naked eye. It is receiving oxygen and some nutrients from you directly, but the placenta is starting to form, preparing the nutrient supply line for your baby as it grows bigger. The cells of the embryo are rapidly differentiating, meaning that they are getting ready to become specialized cells to form the many different organs and organ systems that will make up your baby’s body.
Just like in the first week, in the second-week post-conception, the embryo is still not very susceptible to the mother’s lifestyle choices such as drinking, smoking, or inadequate nutrition. Again, not a green light to party all night, but don’t worry too much if you have imbibed!
Food of the Week: Spinach
Whether raw or cooked, spinach is another excellent source of folate, which is more essential early on than at any other point in pregnancy. Three cups of raw spinach (about 90 g) will provide you with roughly a third of the folate you need per day, whereas a cup of boiled spinach (without salt) contains almost half (260 DFEs). Spinach is also rich in potassium, iron, vitamin A, phosphorus, and magnesium. An easy way to get your spinach is raw in a salad or cooked as a side dish. In addition to the recipe below, also check out the Arugula Salad with Turkey, Avocado, and Dried Cranberries and the Rotisserie Chicken with Apricot Quinoa over Spinach.
Cauliflower, Celery, and Spinach Soup
MAKES 8 CUPS
This creamy vegetable soup is a delicious low-calorie first
course with folate, fiber, and minerals, a great way to start
your meal. It’s also a delicious lunch alongside a grilled cheese
or turkey sandwich.
1 head cauliflower, chopped
8 ribs celery
4 cups chicken or vegetable broth
¼ cup light cream cheese
1 bunch spinach, roughly chopped (or a 5-ounce bag of baby
½ teaspoon onion powder
⅛ teaspoon freshly ground black pepper
Combine the cauliflower, celery, and broth in a saucepan. Bring
to a boil over high heat, then reduce the heat to medium-low
and simmer for 10 minutes.
Transfer about half of the mixture to a blender and add the
cream cheese. Cover and process until smooth. (If your blender
lid has a central cap that can be removed, remove it and drape
a dishtowel over the top so steam can escape while
processing.) Return the mixture to the pot, add the spinach,
onion powder, and pepper, and simmer for 5 minutes more.
(Gestational Week 5)
This is when the embryonic period begins.
Your baby is now beginning what is called the embryonic period, which will continue until the end of week 8 and is marked by the rapid development of the key organs and organ systems. During week 3, the cells of the embryo form into three distinct layers that give rise to the various tissues and organs of your baby’s body. Also during this time, some of the most essential organs start to form, including the heart, the spinal cord, the digestive tract, and the lungs.
With week 3 begins the time when your baby is highly susceptible to
environmental toxins and harmful agents, as well as inadequate
maternal nutrition. Alcohol use during this time can lead to
spontaneous abortion or severe fetal abnormalities, such as fetal alcohol
OH NO, I HAD SOME WINE LAST NIGHT!
Just because developmental problems can occur in response to toxins during this
time doesn’t mean that they will. Many women don’t even know that they are
pregnant at this point, as menstrual cycles can vary depending on several
factors, including stress. Also, if you weren’t paying attention to your cycle, or
maybe not necessarily trying to get pregnant, then you might not realize you are
late this week.
Not to worry! A recent study in Ireland looked at alcohol
consumption in women throughout their pregnancy and found no significant
differences in preterm birth, low birth weight, or growth restriction between women who consumed some alcohol during the first trimester and those who didn’t. Also, the researchers did not find any significant differences in the same outcomes when women consumed alcohol in the third trimester. The reported alcohol consumption in women who drank alcohol was moderate, with the majority consuming 5 units of alcohol or less per week. To put this into perspective, a 175-mL glass of 12-percent alcohol red wine is approximately 2 units.
Food of the Week: Asparagus
A cup of cooked asparagus (180 g) has about half of the daily folate you
need (270 DFEs) and contains other key nutrients, such as potassium,
phosphorus, vitamins A, C, and K, and others. Fresh asparagus is ideal,
but if your grocery store does not always carry it (due to its short
growing season), then use frozen or canned asparagus.
In addition to the following recipe, there are several easy ways to get
more asparagus into your diet.
Chop it up and toss it into a pan with scrambled eggs.
• Sauté whole stalks in a little olive oil with a sprinkle of bread crumbs
on top. The bread crumbs give great texture!
• Serve it with other veggies! Add chopped asparagus to your raw veggie
plate. It is great for dipping and not at all messy to handle.
• Make it an add-in to just about any dish. Asparagus doesn’t have to be
the star of the meal. You can have some on hand and add it to salads
and pasta and grain dishes. It will add color and make the shape and
texture of your meal unique.
Asparagus with Lemon Zest and Paprika
With only three ingredients, this low-calorie, low-sodium recipe
couldn’t be easier or more healthful!
1 pound asparagus, ends trimmed
Zest from 1 lemon
Place the asparagus in a ceramic or glass casserole dish with a
lid. Add 2 tablespoons of water to the dish, cover, and
microwave for 5 minutes. Stir and check for doneness. (If
desired, cook 1 or 2 additional minutes.) Drain the water from
the dish and pat the asparagus with a paper towel to absorb
any excess moisture. Sprinkle evenly with the lemon zest and
paprika and serve.
GROW YOUR OWN
One fun thing you can do is grow your asparagus. Even if you don’t have a green thumb, they are easy to grow, and the best part is that they are perennials, which means they come back every year! When I was pregnant with my daughter, I planted some in our garden (ask for “asparagus crowns” at your garden center). Just like a baby, they take a few years to mature! The first year they are skinny twigs that you can’t eat, but by years 3 and 4 (when your little one is curious and can help your garden), the edible new shoots are bigger and can be harvested. Planting your asparagus bed is a fun and easy activity you can do with your new baby before it even arrives!