20 weeks.

How your baby's growing:
Your baby weighs about 10 1/2 ounces now. He's also around 6 1/2 inches long from head to bottom and about 10 inches from head to heel — the length of a banana. (For the first 20 weeks, when a baby's legs are curled up against his torso and hard to measure, measurements are taken from the top of his head to his bottom — the "crown to rump" measurement. After 20 weeks, he's measured from head to toe.)

He's swallowing more these days, which is good practice for his digestive system. He's also producing meconium, a black, sticky by-product of digestion. This gooey substance will accumulate in his bowels, and you'll see it in his first soiled diaper (some babies pass meconium in the womb or during delivery).

How your life's changing:

Congratulations! You've hit the halfway mark in your pregnancy. The top of your uterus is about level with your belly button, and you've likely gained around 10 pounds. Expect to gain another pound or so each week from now on. (If you started your pregnancy underweight, you may need to gain a bit more; if you were overweight, perhaps a bit less.) Make sure you're getting enough iron, a mineral that's used primarily to make hemoglobin (the part of your red blood cells that carries oxygen). During pregnancy, your body needs more iron to keep up with your expanding blood volume, as well as for your growing baby and the placenta. Red meat is one of the best sources of iron for pregnant women. Poultry (especially the dark meat) and shellfish also contain iron. Some common non-meat sources of iron include legumes, soy-based products, spinach, prune juice, raisins, and iron-fortified cereals.

If you haven't already signed up for a childbirth education class, you may want to look into one, especially if you're a first-timer. A structured class will help prepare you and your partner for the rigors of labor and delivery. Most hospitals and birth centers offer classes, either as weekly meetings or as a single intensive, one-day session. Many communities have independent instructors as well. Ask your friends, family members, or caregiver for recommendations.

Surprising facts: Sleeping during pregnancy

It may become more difficult to sleep through the night as your pregnancy progresses, thanks to some obvious and not-so-obvious changes taking place in your body. You may be surprised to find that:

• You start snoring for the first time in your life, thanks in part to more estrogen, which contributes to swelling of the mucous membranes that line the nose and may even cause you to make more mucus. What to do: Sleep on your side and elevate your head slightly.

• Heartburn and indigestion can make it extra uncomfortable to lie down in bed. What to do: Avoid foods that trigger your heartburn, give yourself two to three hours to digest a meal before going to bed, and try sleeping semi-upright in a comfy recliner or propped up with extra pillows under your upper body.

• Leg cramps jar you out of a deep sleep. What to do: Ease the cramp by straightening your leg, heel first and gently flexing your toes back toward your shins, or walk around for a few minutes.

• You toss and turn all night trying to find a comfortable sleeping position. What to do: Lie on your side with your knees bent and a pillow between your legs. For extra comfort and support, arrange other pillows under your belly and behind your back. Or try using a contoured maternity body pillow.

• You become hot and sweaty in the middle of the night. It's common for pregnant women to feel a little warmer than usual thanks to shifts in your metabolism, hormones, and weight. What to do: Keep your bedroom cool and strip down to the bare essentials. Keep slippers and a snuggly bathrobe handy for those nighttime trips to the bathroom.

• Getting out of bed is harder than ever! What to do: Roll over onto your side so you're facing the edge of the bed. Dangle your legs over the side and use your arms to push yourself into a sitting position. Plant your feet squarely on the floor and then stand up.
Wear sleepwear made of a natural, breathable fiber like cotton. Avoid synthetics, which trap moisture next to your skin and can leave you damp and chilled.

• Sometimes even when you're exhausted, you just can't sleep. So do you toss and turn waiting for sleep to catch up with you — or do something else in the meantime?