Pregnancy Stages & Calender

Planning Ahead

• Getting pregnant can be exciting and scary, but there are several ways you can prepare for the process ahead of time to ensure a healthy start for you and your baby. Ideally, mothers-to-be should take a daily prenatal vitamin that contains 400 to 800 mcg of folic acid to prevent birth defects, like spina bifida, according to the March of Dimes. Drugs and alcohol also should be avoided. Getting to a healthy weight range and talking to your doctor about managing any health problems you may have, like diabetes, also can prevent complications during pregnancy and labor.

First Trimester (Weeks 1-12)

• Since pregnancy is calculated from the first day of your last menstrual period, you likely will not have any symptoms until around your fourth or fifth week of pregnancy. About halfway through the first trimester, you may start experiencing "morning sickness," or nausea, as well as breast tenderness, fatigue, bloating and frequent urination, according to Planned Parenthood. You also may develop acne, darker areolas around the nipples, and a weight gain of about two pounds during the first trimester. Baby's heart may begin beating around five or six weeks, and sex organs may begin differentiating around weeks seven or eight. By the end of the first trimester, your little one will make spontaneous movements and develop skin and fingernails. He also will measure about 2 to 3 inches from the top of his head to his buttocks.

Second Trimester (Weeks 13-28)

• As the second trimester begins at week 13, your bundle of joy still weighs little more than an ounce and measures about 3.5 inches from head to bottom , according to KidsHealth.org. It also is possible to see your baby's external genitalia. You may begin moving into maternity wear during the second trimester, and pregnancy symptoms may become less severe, according to Planned Parenthood. Other problems, like bleeding gums, stuffy noses and shortness of breath, may become more common during the second trimester. As the second trimester continues, your breasts may grow by a cup or two in size and develop obvious veins, according to KidsHealth.org. By the 28th week of pregnancy, your baby measures about 10 inches long from his head to his buttocks.

Third Trimester (Weeks 29-40)

• The home stretch has begun. Women commonly experience sleep difficulties, swollen ankles and shortness of breath during the last trimester, according to WomensHealth.gov. Your face also may swell, and your belly button may protrude. Around 32 weeks, your little one's bones are fully formed and she weighs between four and five pounds. She also measures between 15 and 17 inches long. When you reach 37 weeks, your baby is considered full-term and ready to be born, although she may not appear until several days after your 40th week of pregnancy. Full-term bundles of joy typically weigh between about 6 and 9 pounds, and measure between 19 and 21 inches long.