Week by Week Baby Development – First Trimester of Pregnancy

Wow, there’s a lot going on in there as your baby begins to develop and your pregnant body starts to go through some (big!) changes. Here’s more about what to expect in the first trimester of pregnancy.

You may not look pregnant yet, but chances are you’re feeling it. That’s because a flood of pregnancy hormones is prepping your body to play baby hostess for the next nine months. And that means you could be in line for a bunch of wacky pregnancy symptoms from breast changes to bloating to fatigue to flatulence. Sure, you might be less than thrilled with some of the stuff you’ll be coping with (did we mention heartburn and constipation?), but remember that these temporary discomforts are part of the incredible process that’s happening inside: You’re growing a child!

During the first trimester alone your baby changes from a single fertilized cell (a zygote) to the embryo that implants itself in your uterine wall to a peach-sized bundle of growing limbs and body systems. So much happens in so little time: Organs take shape, baby starts to move (around week eight of pregnancy), and hair follicles and nail beds form. More major first-trimester milestones include the formation of muscles, the production of white blood cells to fight off germs, and the development of vocal cords (I want Mommy!).

For Mom, a lot happens quickly in the first trimester as well. At some point, you’ll likely have a routine ultrasound to make sure things are progressing as they should, and a screening (done through a blood test between 11 and 14 weeks of pregnancy) to look for chromosomal abnormalities such as Down syndrome and congenital heart defects.

In terms of day-to-day stuff, by week five of pregnancy you may be well into morning-sickness malaise (which, unfortunately, doesn’t just strike in the morning!). By week six, you might be wondering who replaced your boobs with those alien orbs (so tender, so tingly, and sooo big!). Pregnancy mood swings may hit by week seven, leaving you feeling up, then down, then up again – and that was just in the past five minutes! Weeks eight through 12 bring a laundry list of other possible pregnancy symptoms , including metallic taste, food aversions, and headaches.

The thing to keep in mind when it comes to pregnancy woes during the first trimester is that every woman is different, so while your neighbor may have moaned about endlessly peeing, that may not happen to you at all. And just because your mom or sister reported cramping or spotting doesn’t mean you’ll do the same. No matter what symptoms you do have, take heart in knowing that most lessen or disappear as your pregnancy evolves.

Your first ob-gyn visit may well be the longest as the doctor goes over your medical history and performs a thorough physical exam. You’ll likely undergo a battery of tests including a Pap smear, urinalysis, and blood work to determine your blood type and Rh status, hCG levels, and the presence of any infections. You might also be screened for genetic illnesses or diabetes, depending on your family history. And while your practitioner is asking you lots of questions, be prepared to ask plenty of your own. Now’s the time to inquire about prenatal vitamins, GERD, weight gain, sexual desire (or lack thereof), or anything (really…anything!) you might be concerned about.