In week 7, your baby will grow to one-half an inch in size -- about the size of a small lima bean. Given the embryo's tiny size, it is astonishing to think of the sophisticated processes that are occurring inside. All the elements of life are contained in that compact little unit, which is working tirelessly to grow and develop and make itself into a person.
At this point in pregnancy, your baby's face is becoming increasingly distinct. The mouth is developing, and the dark spots on the side of the head will eventually become eyes. If you could see your baby, you would probably be able to detect nostrils. Looked at sideways, your baby is developing the beginnings of a profile. The head is disproportionately large, and the embryo -- which still has vestiges of a tail -- is getting longer and a little straighter. The tiny legs resemble fins with toe buds, and the arms are sprouting paddle-like hands.
Important things are happening inside the embryo as well. Muscle fibers are developing rapidly and will move for the first time this week. The heart, which this week divides into chambers, beats 150 beats a minute. The gallbladder, spleen, and liver are solidly in place, and the intestines are forming. With so much going on now, it's more important than ever to avoid smoking and drinking. Smoking has been linked with miscarriage, and drinking alcohol -- heavy drinking or binging in particular -- can cause permanent brain damage in your baby-to-be.
The embryo: burrowing in
This week, the embryo may implant itself even more firmly into the wall of the uterus, and for some women this can result in cramping and breakthrough bleeding. This bleeding, which is usually just light spotting, can be alarming if you don't expect it: Some women worry that they are having a miscarriage, or that the spotting signals a period. But spotting at this point in pregnancy is usually the sign of a healthy pregnancy, not the reverse. Still, call your doctor even if there's just a bit of spotting -- he or she will want to know about it. If the bleeding is heavy or persistent, or the cramping severe, consult your doctor immediately.
During this period, mucus will gather in the opening of the cervical canal to form a solid plug that prevents any foreign substances from entering the uterus. The plug will remain in place until your cervix dilates immediately before your baby is born.
You may find that your morning sickness is more pronounced this week than it has been up to now. You are not beginning to show at all yet, but your breasts are likely growing larger. If you need to buy some larger-size bras, consider purchasing nursing bras that you can continue to use after the baby is born. Many women find that athletic bras are more comfortable for tender breasts. Try wearing a bra to bed if you find that sore breasts bother you at night.
Dizziness, headaches, and snacking
Many women find that headaches are a problem during early pregnancy. It is likely that hormone shifts and the increase in your blood volume are responsible, although no one knows for sure. If you abruptly stopped drinking coffee after learning you were pregnant, you may be suffering from a caffeine-withdrawal headache, which should go away after several days.
Dizziness can also be a problem during the first few months of pregnancy, a symptom likely triggered by changes in your circulation. Hunger and excessive fatigue can cause it as well. Dizziness is usually nothing to be concerned about, but if it is persistent or severe and is accompanied by abdominal pain or vaginal bleeding, you should consult your practitioner immediately, as these could be symptoms of an ectopic (or tubal) pregnancy, which is a medical emergency.
Headaches and dizziness will likely ease with time, but if they are preventing you from going about your usual routine, consult your physician. You'll need to talk to your doctor before using any medications, even herbs, supplements and over-the-counter meds or products. Make sure you are getting enough sleep, because fatigue can cause both headaches and dizziness. Don't allow yourself to go too long without food, either; hunger makes both problems worse. Try stashing some healthy snacks in your purse and in your desk at work, so you can keep your blood sugar level steady between meals.
Pregnancy Calendar, Week 7, from the American Academy of Family Physicians http://www.kidshealth.org/
"Fetal Development -- 2 Months" from Sutter Health, http://babies.sutterhealth.org/babygrowth/fetaldev/bg_fetaldev-2.html
"The First Trimester: What to Expect Mayo Clinic, June 20, 2009, http://www.mayoclinic.com/
Curtis, Glade B. et al. Your Pregnancy Week by Week, Da Capo Press, Cambridge, MA
Campbell, Stuart. Watch Me Grow, Page: 4. St. Martins Griffin. New York
Shanahan, Kelly. Your Over-35 Week-by-Week Pregnancy Guide. Prima Publishing, New York
England, Marjorie. Life Before Birth. Mosby-Wolfe Publishing.
Bradford, Nikki. The Miraculous World of Your Unborn Baby. Contemporary Books.
Supple, William F. Jr. Becoming A Baby. Picket Fence Publishing.