Week 40: You're Due!!!

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This is your Pea in the Podcast for week 40 of your pregnancy. I'm Bonnie Petrie joined by Dr. Laurie Swaim, an obstetrician with Houston Women's Care Associates in Houston, Texas.

Wow it's the big week, you made it, your due date is this week but guess what? You may not have your baby this week. "No, only 5% of babies are actually born on their due date but a lot of people already were delivered. It's a big week because it's an anticipatory week but some may stay pregnant." Believe it or not you may carry your baby for 2 more weeks. "The definition of post dates is 42 weeks and I personally don't believe that babies should be in past 42 weeks, as a matter of fact I think that there's enough evidence to suggest that you don't have a lot to gain by keeping babies in after 41 weeks. There's a very rare woman who will argue with you about that. Most of them are like 'fine, induce me'. But I think it's up to the individual obstetrician and individual patient but somewhere between 41 and 42 weeks is a very reasonable time to have a baby."

So what is your baby waiting for? Well some researchers believe your baby actually releases a chemical signal to trigger labor when it's done baking. There are many who suspect that when your baby's brain is completely mature it sends a signal to the adrenal glands which then start to secrete the hormone cortisol. The theory goes that your baby's cortisol alters the metabolism of estrogen and progesterone and that triggers labor. Another popular theory is the signal comes from the finally finished lungs which begin secreting a certain chemical and enzymes that stimulate the release of what is called prostaglandins, which are the substances that cause the cervix to ripen and help your uterus to contract, essential steps toward labor and delivery. But nobody really knows what that chemical signal is that triggers the beginning of labor.

Now some women who are sick of being pregnant may try various tricks to kick start labor on their own. They range from eating eggplant or spicy foods, using evening primrose oil or red raspberry leaf tea. Drinking caster oil is something that your mother-in-law might suggest, that's a terrible idea though, don't do it no matter who recommends it to you. It causes diarrhea and it can cause dehydration. It is a seriously bad idea, don't do it. Other natural labor induction ideas include sex, since semen contains those prostaglandins I mentioned earlier that are necessary to prepare your cervix for labor, nipple stimulation is the one that's supposed to release oxytocin which causes contractions and some people try acupuncture too. Your midwife or doctor may also stripe your membranes. "Membrane striping is something, it won't induce someone, but if you strip someone's membranes then they will deliver an average of four days sooner than someone with equal gestational age who didn't have their membranes striped. Those four days may be worth a million bucks to you right about now so you may be all for it. Now if your practitioner strips your membranes they are pulling your water away from the mouth of your cervix and lower uterus. That should irritate your cervix and generate the production of those now famous prostaglandins. Sometimes it takes three or four attempts though to start labor from striping membranes. Heads up, many women report that membrane striping hurts. Finally you can try something like bouncing on a birthing ball or walking and walking and walking, up and down hills, and up and down stairs, but Dr. Swaim says don't expect your baby to pay any attention to your flurry of activity. "She's more than welcome to walk all she wants. She can have sex and spicy food but she's going to go into labor when it's time for her to go into labor."

Now if your baby is still quite comfortable in there at week 40 your doctor may start talking to you about considering an induction for next week. It depends also how favorable her cervix is, but at least in my practice then I will suggest induction at 41 or slightly after, weeks. The reason also is because we have to schedule it at our hospital, they have to get on a list. There are some patients who don't want to be induced and I'm okay with that but then they'd have to have natal testing, they'd have to have biophysical profiles a couple of times during the week to make sure the baby is okay, the fluid's okay, the movement, etc." Now we touched on induction a little bit last week, what happens is your doctor tries to jump start labor using synthetic forms of those natural substances, prostaglandins and oxytocin, that we've been talking about in this podcast. "Yeah it's the same stuff and it also sort of depends on the patient. Sometimes we have to ripen the cervix first before we use pitocin and there are various ways you can do it. A common way to do it is a drug called prostaglandins. Some people use a folding balloon and some people just rupture membranes. If we can rupture membranes, typically in our area that's one of things that we do and yes, then we use pitocin." One thing that becomes a concern as you move into and through week 40 is that your baby will pass meconium. "Meconium just means that the baby has passed its intestinal contents, it happens quite frequently, it's not necessarily a bad thing especially if the baby looks fine on the monitor."

Now your baby's been building up meconium in its intestines for weeks and weeks and weeks. There are skin cells and mucus and bile and amniotic fluid and lanugo all in your baby's intestines. If your baby passes it before birth your doctor may ask for a special neonatal intensive care team to be available in case there was ingestion of the meconium into your baby's lungs. Now this can lead to something called meconium aspiration syndrome. Between 5% and 20% of newborns pass meconium before birth, only 5% to 10% of them get meconium aspiration syndrome. Most likely though you'll be dealing with meconium the first time you change your baby's diaper. It's dark green, almost black in color; you'll know what it is when you see it.

So what is your cramped, full-term baby doing in there? "Hanging out, sucking the thumb, waiting to be squeezed out." Now your baby may weigh now as little as five pounds or may be as large as 10 to 11 pounds, the average weight of a baby born at 40 weeks is seven pounds, eight ounces. Most babies are 20 to 21 inches long or so.

From week one, when you were still planning your pregnancy, to now when your baby is all but ready to be born, you have done a great job mommy. Can you believe you've made it here? Dr. Swaim can, she says pregnancy is the most natural process in the world, "Pregnancy is not an illness. It's a natural phenomenon and sometimes there are discomforts but there's also wonderful things, you get a big prize in the end. Ask your questions, trust your instincts and if there's something that I said that sounds screwy to the patients then they should bring it up with their doctor. People have different expectations about what is going to happen and the fact is that basically we can control not much of it. But everyone has the same goal: healthy baby, healthy mom. That's what the patients want, that's what the doctors want, that's what the nurses want. So here's sending you easy labor vibes and may you have the labor and delivery of your dreams. And while I have this opportunity I'd like to say welcome to the world baby, we've been waiting for you.

That's your Pea in the Podcast for week 40 of your pregnancy. For a transcript of any of our Pea in the Podcasts go to our website peainthepodcast.com. For Pea in the Podcast, I'm Bonnie Petrie, thanks for listening.