“Ideally, women should discuss their health and medical situation with a health care provider before pregnancy,” says Dr. Susan Bathgate, assistant professor of maternal-fetal medicine at George Washington University in Washington, D.C. “This is important because many women don’t realize they are pregnant until about five or six weeks after they have missed a period, and then some important development has already taken place.”
Now is not the time to take on any dangerous or unique new exercise.
Prior to and when you’re pregnant, health care providers suggest you exercise in moderation. Now is not the time to take on any dangerous or unique new exercise, says Dr. Spencer Richlin, staff physician and specialist in reproductive endocrinology at Reproductive Medicine Associates of Connecticut.
Eat healthy and include omega 3 fatty acids and folic acid in your diet. Taking vitamins containing folic acid for three months prior to getting pregnant dramatically reduces the risk of having a baby with spina bifida or other open spinal cord defects. Health care also should include a pap smear and vaccinations to prevent infections that can affect pregnancy.
In addition, avoiding alcohol, recreational drugs and tobacco during pregnancy and even before can reduce the risk of fetal alcohol syndrome and birth defects, says Dr. Robert Snyder, an obstetrician and gynecologist in Federal Way, Wash. “In fact, we try to limit exposure to all medications, even over-the-counter ones, and recommend that women not get their hair colored or permed to avoid exposure [to harmful chemicals] during this critical time,” he says.
That said, let’s see how that miracle of life inside you develops during the first 12 weeks of your pregnancy.
Weeks 1 and 2
Because most women can’t pinpoint the day they conceive, doctors calculate the baby’s due date starting from the first day of your last menstrual period. The average pregnancy lasts from 38 to 40 weeks, but for the first two weeks of that time you’re not yet pregnant. Your body, however, is getting ready to accommodate a baby.
As the uterus sheds its lining and causes the bleeding known as your period, your hormones are preparing eggs for release. When the uterine lining builds up again, ovulation, or the release of eggs, occurs.
If the conditions are optimal, your partner’s sperm will fertilize one of your eggs within one to two hours after intercourse. And voila! You’re pregnant.
At this time the embryo or fertilized egg is the size of the head of a pin and doesn’t look like a baby but, rather, like a group of cells multiplying. This cell action takes place as the fertilized egg floats down the fallopian tube to the uterus.
“The embryo is most vulnerable during the period from three to eight weeks after conception since all the major organs are developing at this time and are at risk for resulting in birth defects,” says Bonnie Berk, a registered nurse and childbirth education specialist in Carlisle, Pa.
During the first trimester of pregnancy, the brain, spinal cord, heart and gastrointestinal tract all begin developing, according to the American Pregnancy Association.
Weeks 4 and 5
Your baby is still very small, about 0.04 to 0.05 inches in length. Layers of cells have already grouped according to their functions. The outer layer will become the nervous system, skin and hair; the inner layer will be the breathing and digestive organs; and the middle layer will become the skeleton bones, cartilage, muscles, circulatory system, kidneys and sex organs. The placenta, which nourishes the baby, and the amniotic sac, which surrounds the baby, also are forming during this time.
The embryo now looks like a tadpole and is comparable in size to a BB pellet. Eyes and limb buds are developing and blood circulation is well established. The earliest forms of the liver, pancreas, lungs, thyroid gland and heart appear. Sometimes a heartbeat can be detected by an ultrasound this week.
The embryo is the size of a small raspberry with leg buds that look like short fins. Hands and feet that have a digital plate where fingers and toes form will develop. The tongue is beginning to form, eyes appear as dark spots and the head is relatively large. The brain and spinal cord are emerging from the neural tube.
Your baby is about the size of a grape. Eyelid folds and ears are taking shape, and the tip of the nose is visible. Arms have grown longer and now bend at the elbows. Places where fingers and toes will be are notched. Sexual organs, cartilage and bones are forming.
The embryo can be as long as 1.2 inches and is about the size of a strawberry. Your baby moves its body and limbs, which is visible on an ultrasound, though gender probably can’t be identified yet. The head sits more erect on a more developed neck. Eye muscles, the upper lip and ear canals take shape.
Although your baby weighs less than two-tenths of an ounce and looks like a medium shrimp, it’s now officially a “fetus.” “Fetus” is Latin for “young one.” The eyes are covered by skin that will eventually split to form eyelids. Taste buds have begun to emerge.
This concludes the most crucial time of your baby’s growth. Feel free to let out a sigh of relief!
The fetus is now the size of a large lime. He is swallowing and kicking, but you won’t be able to feel it yet. Fingernails and external genitalia appear. The head looks to be almost half the size of the fetus. Ears are low on the sides of the head and teeth are starting to form.
Your baby is now fully formed and may weigh as much as 1.5 ounces and measure up to 2.5 inches in length. The liver is making blood cells and the gallbladder secretes bile.
In the majority of cases, pregnancy becomes more physically enjoyable after the twelfth week. Chances of miscarrying after the first trimester are only four percent, according to Dr. Brad Imler, president and CEO of the American Pregnancy Association. Fatigue and nausea will likely go away by this time, so now is the time to enjoy and savor being pregnant!