40 Weeks Pregnant: Baby at 40 Weeks

It's week 40 of your pregnancy! Bet you’re pretty ready to…play ball! Your baby is around 6-9 lbs. by now; the average is 7 ½. She’s got hair on her head (or maybe just peach fuzz), eyebrows, eyelashes, a cute little nose, fingernails and toenails. Her hands can grasp, her mouth can suck and swallow, and her lungs, heart and stomach are ready to go. She’s been peeing into your amniotic fluid for months, but she has yet to take her first bowel movement. If she does so before birth, it can be a sign of fetal distress. You’d notice it if your water breaks and is smelly or discolored. It’s theorized that babies can also poo in the womb if they are post-term because their digestive system is mature.

Meconium, this first bowel movement, is made up of amniotic fluid, fetal cells and lanugo, the layer of hair that covered her in the womb. You’ll be cleaning it off your newborn for a few days. As she drinks milk, her poop (you’ll become very, very familiar with her poop!) will gradually lighten and change colors. A healthy breastfed newborn’s poop is yellow, liquidy and seedy-looking. A healthy formula-fed newborn’s poop is light brownish and pasty, like peanut butter.

Size of baby at 40 weeks pregnant: Your baby is about 6-9 lbs and the size of a watermelon.

40 Weeks Pregnant: What to Expect

Still pregnant? Hang in there. The majority of women deliver in the week and a half following their due date, though we’re aware that every day feels like an eternity. Your baby is sitting deep in your pelvis, and all that pressure is making your vulva feel very swollen. “Lightening crotch,” or sharp shooting pain, is caused by this pressure.

Unless your baby is breech or transverse, her head is pushing up against your cervix, already starting to thin and dilate. Dilation can take a long, long time and you might not feel it happening. If you’re curious, your prenatal care provider can check your progress.

Vaginal secretions have increased, but keep an eye out for something that looks sticky, like egg whites. This is your mucus plug. It can come out all at once, or bit by bit, and it is a great sign that labor is approaching. Bloody show, or pinkish or red-tinged mucous, is another indication.

If your water breaks, call your doctor right away; labor is likely right around the corner. In the case of PROM, or premature rupture of membranes, your doctor or midwife will tell you how long you go before inducing labor. That’s because your bag of waters protects your baby from infection, and the more time that passes after rupturing, the more you risk infection.

40 Weeks Pregnant Symptoms:

Common symptoms during your 40th week of pregnancy include:

  • Braxton Hicks contractions
  • Diarrhea
  • Leg cramps and pelvic pain
  • Nesting instinct
  • Insomnia
  • Cervical dilation or effacement
  • Changes in fetal activity or baby “drops”

40 Weeks Pregnant: To-Do List

  • Enjoy time with your partner: Everyone is probably telling you to “sleep while you can” or to fit in activities that are hard to do once the baby arrives. Easier said than done, especially if you’re the one 40 weeks pregnant! But there is truth to it. After the baby comes, you’ll be busy around the clock. Go out to dinner, see a movie and visit with friends.

  • Ask for postpartum support: And be specific. If family and friends are offering to help, tell them exactly what you need—meals, walking the dog or just holding or rocking the baby to give you a break. (You might want to add SNOO Smart Sleeperto your "village." It's like an extra set of hands after grandma leaves!)

  • Compile questions for your first pediatrician appointment: You’ll need to know how often you’ll need to visit during those first few months. You may also want to ask questions about immunizations, breastfeeding tips, etc.

  • Read up!It’s easy to get wrapped up in labor and delivery, but that is merely one day (or a few days) in the lifetime of your child. Here are 5must-read articles that will make the first few days with your baby easier:

We also highly recommend reading (and watching!) The Happiest Baby on the Block. The book answers tons of new parent questions and the DVD is hands-down the best way to learn the 5 S's baby calming technique!

Pregnancy Quote of the Week

People who say they sleep like a baby usually don't have one. —Leo J. Burke

39 Weeks Pregnant

About Dr. Harvey Karp

Dr. Harvey Karp, one of America’s most trusted pediatricians, is the founder of Happiest Baby and the inventor of the groundbreaking SNOO Smart Sleeper. After years of treating patients in Los Angeles, Dr. Karp vaulted to global prominence with the release of the bestselling Happiest Baby on the Block and Happiest Toddler on the Block. His celebrated books and videos have since become standard pediatric practice, translated into more than 20 languages and have helped millions of parents. Dr. Karp’s landmark methods, including the 5 S’s for soothing babies, guide parents to understand and nurture their children and relieve stressful issues, like new-parent exhaustion, infant crying, and toddler tantrums.

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Disclaimer: The information on our site is NOT medical advice for any specific person or condition. It is only meant as general information. If you have any medical questions and concerns about your child or yourself, please contact your health provider.