Study Gives New View of 'Full Term' Pregnancy

Ez - posted on 05/25/2011 ( 38 moms have responded )

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Babies born between 39 and 41 weeks of pregnancy fare better than infants born during weeks 37 or 38, a study shows.

A term birth is considered 37 to 41 weeks, but the new study suggests it is more of a continuum.

The findings appear in Obstetrics & Gynecology.

Previously it was thought that infant mortality risk was similar for babies born between 37 and 41 weeks. But the new study shows that this risk is increased when babies are born between 37 and 39 weeks of gestation, and that this risk decreases with each additional week of pregnancy.

"A truly elective delivery should wait until at least 39 weeks," says study researcher Uma M. Reddy, MD, MPH of the Eunice Kennedy Shriver National Institute of Child Health and Development in Bethesda, Md.

"We don't stop labor at 37 weeks, and the majority of babies will do fine," she says. But "if nothing is going on and you are doing well, waiting to 39 weeks is best for you and your baby."

Overall Risk of Infant Mortality Is Low
The overall risk of newborn death remains small, but it doubles for infants born before 37 weeks, compared to infants born at 40 weeks. In 2006, infant mortality was 1.9 deaths for every 1,000 live birth when babies were born at 40 weeks. This rate increased to 3.9 per 1,000 live births when a baby was born at 37 weeks, the study showed.

"Don't pressure your doctor to deliver you any earlier," "Reddy says. "The definition of term is arbitrary and 37 weeks isn't magical because it is the beginning of term."

Researchers looked at data on 46,329,018 births that occurred from 37 to 41 weeks gestation between 1995 through 2006.

The new study did not include information on the type of delivery (caesarean section vs. natural birth) and/or the reasons for preterm delivery.

Redefining 'Term'
"We need to make people aware that within the definition of term, there are two categories," says Alan R. Fleischman, MD, the medical director of the March of Dimes in White Plains, N.Y.

Term is "a biologic continuum between 37 and 41 weeks and those babies born early in term are different than those babies born at full term," he says.

The new findings apply only to women who do not have medical reason to deliver before 39 weeks, he says.

But "there is a whole group of women and doctors who are delivering early for convenience or due to a very minor change in some test that has not been shown to be helpful," he says. "It is a perfect storm because you never see a mother who likes the last four weeks of pregnancy. It's uncomfortable and many feel it is time."

J. Christopher Glantz, MD, MPH, a professor of maternal-fetal medicine at University of Rochester School of Medicine, agrees. "The definition of term is a little arbitrary and it is an old definition based on how babies did many many years ago."

Most babies do OK at 37 weeks, he says. "The differences are not that dramatic between the actual risk of mortality from 37 to 39 weeks, but why take any unnecessary risks at all?"

"Elective deliveries prior to 39 weeks definitely have some increased morbidity," says Abdulla Al-Khan, MD, the director and chief of maternal and fetal medicine and surgery at Hackensack University Medical Center in New Jersey Other factors such as type of delivery and reason for early term delivery also affect these risks, he says.

http://www.webmd.com/baby/news/20110523/...

So next time someone claims 37 weeks is 'term' and they are going to take that castor oil, book that induction, or schedule that c/s, kindly refer them to this new study :-p

MOST HELPFUL POSTS

April - posted on 05/25/2011

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I also agree with the article. As I said on another thread, it helps to understand how due date is estimated. We are all different, with different period lengths, different luteal phases, and we also vary in the number of cycle days(for some of us, the number of days in our cycle changes by 1 or 2 days each month). We are all so different, yet all of our babies' due dates are based on a woman with a 28 day cycle who ovulates on day 14. Personally, I don't think due dates should exist anymore. I think there should just be a "due month" or due months if your child could be born at the end of 1 month or the beginning of another. By focusing so much on due date and basing inductions around that time, one might actually give birth to a premature baby.

Sarah - posted on 05/25/2011

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I always thought that full term was 40 weeks.
I don't know where people get the idea it's any earlier! :)

Rosie - posted on 05/25/2011

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i'd like to p[oint out how it states 41 weeks, not 42. i get weary when i hear women state, the baby will know when to come out, they should wait until then stuff. the closer you get to 42 weeks the more chances of having your placenta give out, or the baby aspirating meconium. i don't understand taking the chance with that either. :)

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Mel - posted on 05/28/2011

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I had 4 scans with both girls, but with paige it was only due to bleeding, but I knew my due date before my scan with Paige because I did the pregnancy test at 4 weeks 1 day. Thanks for the info about how they do them in other places

Emma - posted on 05/28/2011

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In the UK scans are done at 12-14 weeks and then at 20-22 weeks. No other scans are done unless it is a high risk pregnancy or there are suspected problems.
I don't know about all areas in the UK but where I had my baby the hospital point blank refuse to induce before 41weeks and 5 days. There is no options, for convenience or for being fed up. The only time induction is done earlier is if there are problems. Also, home births are becoming more common in the UK, but are not allowed if baby comes before 37 weeks or after 42 weeks...then hospital birth is mandatory due to extra risks involved in the labour.

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Thinking back i was 12weeks on my first child, at her first scan.They told me she was 16-17 weeks.I moved hospital then for my own reasons.I was told no way, were going by your dates..Now i am sure a 12week baby looks different to a 16-17 week old baby.Although her head size was larger than a 12week old fetus as he said.She was very active for a 12week baby.If i had of stayed with them.I would of had my baby a lot early as the would think i was going weeks over due.She was an early September baby by the first hospital but she was born late september.I say if i had of stayed with them she would of been born 2-3 weeks early..i had her in my 39th week anyway.Crazy.lol

Dana - posted on 05/27/2011

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I'm from the US and I've had 4 scans by 20 wks but, I'm abnormal. ;) With my son Ethan I had one at 8 wks and then another at 20 some weeks or so.

I really can't say much about the full term side of the topic, Ethan was 6 weeks early but, did score a 9 on the APGAR and another 9 after the 5 minutes or whatever it is when they do another. He was a big healthy preemie so I was rather lucky.

Emilie - posted on 05/27/2011

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I was going to be induced early with my first child. He was breech and I went in to have him turned. The doctor was considering going ahead and delivering him since I was already addmitted to the hospital. They did a test and determined that his lungs were not yet ready and that was at 37 weeks, I had a C-section 2 weeks later and he was big and fine his APGAR was 8 right after birth and 10 like 5 min later. So, even though he was big and I was ready at 37 weeks, he was not.

Charlie - posted on 05/25/2011

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Both my doctors said I wasnt full term until 41 weeks ....both my children went over that before I was considered for induction ..

Kate CP - posted on 05/25/2011

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I knew exactly when I conceived my son and he was exactly, TO THE DAY 37 weeks. I was on Clomid and I knew exactly when I ovulated and based on when I had intercourse I knew exactly when that baby was made.

Merry - posted on 05/25/2011

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I just had the one at 18 weeks, I knew my last period date so that was the only one recommended to me. I'm in USA

Jodi - posted on 05/25/2011

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No, I didn't think late growth scans were standard. I had a crazy number of them too because of the opposite problem in my third trimester - they were SUPER worried about her being too small (and that DID turn out to be the case).



But realistically, I do think that if you can't be certain of conception date or LMP, a 6-10 week scan is a really good idea, because this is the MOST accurate time for estimating a due date. Those later scans, they are simply guessing really. You have NO idea how often they quizzed me as to whether my dates were out (as in I conceived later), and there was no way I was out. My pee test gave me a positive 4 weeks after a confirmed miscarriage. And that's when thos later scanners tried to tell me I conceived, purely because of size. Whereas those earlier scans focus much more on the early cell development, which is pretty definitive.

Ez - posted on 05/25/2011

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On the frequency of scans in Aus, they are all up to the woman's discretion. Some women decline the 12wk NT scan (not many). Some women don't need an early dating scan because they are sure of their ovulation and LMP dates. But going by what I see at work, the average woman with an average pregnancy has an early dating scan (6ish weeks), the 12wk NT scan, and the morphology scan at 20wks.



I personally had several more because of a couple of some bleeding at 21 weeks, and then several growth scans in my 3rd tri because my fundal height was ridiculously off the chart. But late growth scans are not standard here (thankfully, because they are notoriously inaccurate anyway).

[deleted account]

"I just wonder how they know for sure when you first conceived?"

If you go through IVF/IUI, you know EXACTLY when you conceived.

Jodi - posted on 05/25/2011

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@ Mel, to answer your question about scans, I am not sure what the standard is any more. When Jayden was a baby, it was just a single scan at 16-20 weeks, unless need dictated otherwise. With Taylah, I am not certain because I had an exceptional situation, so my pregnancy was treated based on my individual circumstances, and even THAT was 6 years ago. So things have possibly changed. Erin and Loureen probably have a better idea on that, as their kids are younger :)

Merry - posted on 05/25/2011

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Good point erin, my obgyn said the beginning of 41 week is necessary to induce so 7 days post date
My midwife said the completion of week 41 or 14 days post date. Big diff as I went into labor on 9 days post date and had I still been with the obgyn she would have induced me at 7 days past...

Ez - posted on 05/25/2011

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It depends if we're talking about the 41st week, or 41 completed weeks. Seems pedantic I know, but it makes a difference. Where I live (and most other places in Aus), the public hospital system doesn't induce for post dates until towards the end of the 41st week. That's where the 42 weeks comes into it Kati. The research has always supported the fact that the increased risks don't start until the completion of 41 weeks.

It's not clear from this article which standpoint this new study is taking (41st or 41 completed) in making their conclusions. I will try and google later.

Merry - posted on 05/25/2011

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Eric was right 'on time' at 4 hours past his due date. Fierna was 'late' at 41+2 days but I believe she was just as on time as Eric. Both were just 8 lbs both appeared perfectly on time. Eric passed meconium, Fierna did not. I believe Eric passed it cuz of the stress of my long hard labor etc, Fia had a nice short labor and I was so much more relaxed with her. I think it's good to not induce before 39-40 weeks cuz you never know if the date is a week or so off. My friend wanted a elective c section at 37 weeks, her dr held her off til 39 weeks but she ended up going into natural labor right before the scheduled section :) yes it's hard being so big and pregnant but honestly pregnancy is easier then having a newborn so idk what the rush is!

Vera - posted on 05/25/2011

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I just wonder how they know for sure when you first conceived? So their idea of 40 weeks could be off by say 3 - 5 days making it a week or more off. Lets say with my pregnancy (just an example... not saying it happened)



I am irregular and that my "that time of month" doesn't always come or sometimes it is only spotting for a day. I was pregnant and never knew for a couple of months. My doctors did sono and then gave me a due date of what they thought was right according to the sono. But later I am given 3 more due dates as time goes by and all 3 due dates with in weeks of each other (not days - weeks) So their idea scientifically for a full term pregnancy may not be corret if I had actually conceived later than they thought meaning I should have carried my baby to 43 weeks - but to them she would have been late by 3 weeks.



Not sure if that makes sense. So unless they can for sure pinpoint a for sure date on the fetus I don't think they can up their scientific findings to 41 weeks.



Additionally a mom that really is right on with her target due date and is say 42 weeks along runs a SEVERE risk of having low fluid, and the baby pooping... sooo many problems can happen by then - and most risks no mom wants to take. I know



I know I was worried the night my daughter was born we started week 43. She came when she was ready - I knew she would - fashionably late like her mom (ha ha ha)



Maybe they should study more into getting those due dates correct - it'll help the rest of the science.

Rosie - posted on 05/25/2011

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i've heard many women on this site claim the baby should stay in for however long it wants to. i was simply addressing that. :)

Kate CP - posted on 05/25/2011

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"I agree with it. We were just the exception, with Adelaide born at 38 weeks, and a 10 on her first Apgar. She just cooked fast :).

But she was ready and came on her own. Totally different than trying to force labor. It's the baby that initiates the hormone response."

I actually found an article somewhere that showed there was a correlation between preterm labor and an infection in the amniotic fluid.

Lemme see if I can go find it...

Oh, and to respond to the OP: Yes, I fully agree with this study. My babies were both early, my daughter 2 weeks early and my son a month early. After 6 days of labor with my son I was SO ready for him to be born. :/

Bonnie - posted on 05/25/2011

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37 weeks is considered full term, but it is common sense to wait as long as you can if nothing is wrong.

Mel - posted on 05/25/2011

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my bub was born at 39 weeks and she had some feeding issues also couldnt get her to feed she fed maybe once in morning then at about 2pm for only about 5 minutes then just slept all day then was awake all night, she had other issues to. I think she was more early then 39 weeks but my second was perfect born at 41 weeks + 1. Most babies I have seen born around 37-40 weeks are fine but any earlier usually have some feeding troubles. When I was doing research about the risk of going past 40 weeks I saw alot of mums lost thier babies due to not being induced and they died before being born at 41 weeks or 42.

I agree Laressa I dont wish for an early baby ever, full term babies you dont have to wake for feeding and stress about thier weight

Laressa - posted on 05/25/2011

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I definitely agree. My water broke at 37 weeks in my first pregnancy. I had to be induced when I did not have very strong contractions 12 hours later. My daughter was born weighing just over 6 lb and healthy. But she did not have a strong sucking reflex and had to feed her with a syringe for the first week. Nurses said they see that frequently in babies under 38 weeks. My next pregnancy thankfully my son waited to come till 39 weeks. Much as I was getting tired of being pregnant I was not one of those women wishing for an early baby. I knew what having an early baby was like. Its more work than a full term newborn.

Mel - posted on 05/25/2011

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I only read Jodi's response, how many scans are done in other states in WA we have the first scan sometime after 6 weeks, second at 12 weeks then 18-20 week one and another if needed I had 36 week one...

Jodi - posted on 05/25/2011

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I am not sure if it is general practice here. I didn't have one with Jayden. But that was 14 years ago. With Taylah, I had one because I'd had 2 miscarriages and my cycle was all over the place, so he wanted a better idea on it, so we did one earlier. I think here, the standard is a scan at 16-20 weeks, and unless you are high risk or have issues that crop up, that's it. I ended up with a lot more scans and a lot more suggested due dates simply because my daughter was very small, but that original scan was the most accuratel.

[deleted account]

I had a planned c-section, and my doctor suggested a date (I think convenient for him) around 37 weeks, but the idea freaked me out. I almost decided to attempt a natural birth (which wasn't recommended for me) rather than have a c-section that early.



In the end, we scheduled for 39 weeks. My baby had a perfect Apgar score. Would 10 days have made much difference? I don't know, and I'm glad I didn't have to find out!

Jodi - posted on 05/25/2011

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I do think a part of it, when a woman isn't sure of her cycle, or her LMP (as I wasn't), there need to be ultrasounds at certain points that will determine with a better degree of accuracy. I had my first ultrasound at 10 weeks because I didn't have an LMP to use as an approximate due date. So a scan was used. In those early weeks, it is very easy for them to determin developmental milestones, because every week there are huge numbers of milestones met, and they are quite accurate.

So they gave me a due date based on 10 week scans (not LMP) and I delivered at 39 weeks 3 days.

Blah, I'm rambling.

Minnie - posted on 05/25/2011

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I agree with it. We were just the exception, with Adelaide born at 38 weeks, and a 10 on her first Apgar. She just cooked fast :).



But she was ready and came on her own. Totally different than trying to force labor. It's the baby that initiates the hormone response.

Jodi - posted on 05/25/2011

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Wow...I didn't realise this was rocket science. I always thought full term was 40 weeks too, and realistically, given that conception CAN occur anytime in the cycle, what IS the likelihood that they are fully baked at 38 weeks? Not very likely. YES there is definitely a probability of 42 weeks. It all depends on a woman's cycle. Less than 39 weeks, a full term baby would be pretty rare.

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"Just shouldn't be inducing before 40 weeks for anything other than medical complications. "

Which is why I went all batshit when my doctor told me she has to induce at 36 week due to onset of kidney failure. I begged her to wait one more week. Nope. She went down that road with my sister 6 months prior, and now she's on dialysis.

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