Probablity of Induction after a given day

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Induction odds by day

Here's the big question this graph is trying to answer:

The western world likes to induce babies rather than let them go too late, doesn't this skew your results by removing late babies from the "late" end of the spectrum where they should be?

I don't think so. This survey contained 3086 births resulting from inductions (out of 13017 total). Only 7% (226) of the inductions were at or past 42 weeks, 0 D. By that time, 96.7% of all spontenous labors have already happened. At 41 weeks 0 days, 10216/13017 (78.5%) of spontaneous labors had already happened. But only 1034 inductions happened after that date.

There's a study that suggests the average first time mom goes into labor 8 days past her due date. Even though the study is 20 years old, the notion of moving everyone's due date to 41W1D has not caught on. Why not?

The survey results show that there were 7018 spontaneous labors before 41 weeks and 2913 spontaneous labors after 41 weeks. If all 1034 inductions were added to that "spontaneous" count, that'd mean there were 3947 babies born after 41 weeks... not enough to tip the scales. What if all the inductions after 40 weeks (1775) were actually supposed to be spontaneous labors after 41 weeks? That'd mean 4688 babies would be born after 41 weeks. Remember, we'd need at least 7018 to happen spontaneously after 41 weeks to match the ones that spontaneously happened before 41 weeks; a median means that half happen before, half after. It'd be tough for the median to move a whole 7 or 8 days. It all tells me that reducing inductions will not shift the median to the right a whole lot.

I've also added a table here that shows how the median would shift if ALL inductions, not just the later ones, were actually supposed to be "late" births.

Does the data change for first time mothers?

I've received a lot of questions about whether these statistics shift for first time mothers. You can click here to exclude all non first-time moms

Induction odds by day

DayTotal pregnancies remainingHow many will end in induction
#% #%
245 13017 100 3086 23.7
246 12991 99.8 3079 23.7
247 12969 99.6 3077 23.7
248 12951 99.5 3074 23.7
249 12921 99.3 3067 23.7
250 12886 99 3054 23.7
251 12855 98.8 3046 23.7
252 12829 98.6 3044 23.7
253 12772 98.1 3025 23.7
254 12732 97.8 3012 23.7
255 12682 97.4 3002 23.7
256 12633 97.1 2995 23.7
257 12591 96.7 2986 23.7
258 12541 96.3 2977 23.7
259 12478 95.9 2961 23.7
260 12361 95 2919 23.6
261 12267 94.2 2893 23.6
262 12171 93.5 2866 23.5
263 12064 92.7 2845 23.6
264 11939 91.7 2822 23.6
265 11825 90.8 2799 23.7
266 11673 89.7 2775 23.8
267 11472 88.1 2722 23.7
268 11294 86.8 2672 23.7
269 11100 85.3 2624 23.6
270 10875 83.5 2588 23.8
271 10592 81.4 2543 24
272 10337 79.4 2492 24.1
273 10018 77 2424 24.2
274 9577 73.6 2291 23.9
275 9185 70.6 2176 23.7
276 8817 67.7 2095 23.8
277 8349 64.1 1995 23.9
278 7872 60.5 1913 24.3
279 7414 57 1841 24.8
280 6901 53 1775 25.7
281 5888 45.2 1614 27.4
282 5299 40.7 1529 28.9
283 4775 36.7 1434 30
284 4271 32.8 1337 31.3
285 3785 29.1 1230 32.5
286 3313 25.5 1146 34.6
287 2801 21.5 1034 36.9
288 2249 17.3 874 38.9
289 1813 13.9 740 40.8
290 1460 11.2 622 42.6
291 1099 8.4 492 44.8
292 832 6.4 390 46.9
293 619 4.8 301 48.6
294 435 3.3 226 52
295 269 2.1 137 50.9
296 170 1.3 71 41.8
297 111 0.9 41 36.9
298 69 0.5 24 34.8
299 49 0.4 17 34.7
300 31 0.2 10 32.3

Due Date Survey Data

Due date statistics: A study on the length of pregnancy
Probability of delivery resulting from spontaneous labor after 35 weeks
Probability of delivery within x days of a given date
Length of pregnancy by week
Spontaneous labor and due date determination
Length of pregnancy, comparing subsequent births for individual moms
Length of pregnancy for first time vs. second & third time moms
Length of pregnancy, type of delivery
Gestation vs. Birthweight
Probablity of Induction after a given day
Average day of spontaneous labor vs. age of mother at time of birth
Are more babies born during a full moon?
What's the most common day of the week for babies to be born?
I'm still pregnant at 40W. What's it mean?
Do winter babies arrive later?
What if I know my conception date?
Are boys or girls born later?
Subsequent pregnancy date search
How do inductions bias the due date statistics?
Download the data
Birth Stories
Survey input dates

More Resources

Pregnancy Day-by-Day
Fast pregnancy calendar
Baby age calendar
EDD Icon Generator
Jo's Birth Story
Weeks vs. Months Explained
Charts generated by flot
spacefem.com
spacefem@spacefem.com

Recent Comments

For more support, encouragement, Q&A,
you are invited to join our pregnancy forum. We are dedicated to answering complicated questions as logically as we possibly can.

Clock-Ticking

Sat Aug 19 2:18 AM by lovernotafighter in Pregnancy & Parenting

Thank you everyone. :) Any info about egg-freezing is appreciated. Although, my wife can always donate hers too. Good luck, Sonic. :) Many prayers for you both! :)(sufiMYSTIC) *I'm back to my original profile, lovernotafighter.*


bad reasons for having a baby

Tue Aug 1 1:47 AM by rowan in Pregnancy & Parenting

but I take them to restaurants so I know they end up hating 90% of the things they ask for.
:lol:



- kid would like a sibling

- maybe people are right about end of life stuff



That's about it. I hated being pregnant, the last time I was pregnant the hormones were... really awful. Plus kid is now pretty big so another one would be weird and we gave away all our stuff. ;)


how do you travel?

Mon Jun 19 11:00 AM by DarkOne in Pregnancy & Parenting

We're traveling with a 2 yo and a 4yo this week. A 2 hr flight connecting to a 4 hr flight. I broke down and got tablets and headphones, now I just need to load them with movies/games. I'm packing treats and stickers and crayons and notepads. I'm almost positive I'll be carrying on a (very compactable) pillow, 'cause they don't give those out anymore on board. I'm banning toys that can roll several aisles fwd or back when inevitably dropped (besides the crayons). I was planning on gum for ascent/descent, but I think the suckers for the 2yo will be better. I'm so not looking forward to these flights. Maybe the kids will surprise me and be awesome. I'm not worried about the 4yo. But the 2yo...


Bilingual Toddler

Wed May 3 10:19 PM by Nachos in Pregnancy & Parenting

Bilingualism! This is something I know a lot about! My last job was to speak English to my class in a partial immersion school and the kids picked up English so fast but spoke back to me in German. We worked on saying different words in German and in English and it meaning the same thing and I read English books to them. They differentiated pretty well but most of them came from a mono-lingual family background.



I can still highly recommend this book: (https://www.amazon.com/Third-Culture-Kids-Growing-Revised/dp/1857885252) for bilingual children. Some very good advice in there.



Also, keep speaking English! Toddlers forget fast when a language is no longer present.



Yay bilingualism!


New parent help/suggestions

Sat Jan 14 10:07 PM by antfancier in Pregnancy & Parenting

I agree with everything lyra211 said and will add a few more.



Things you don't need:

Anything soft, fluffy or furry. My baby couldn't care less about minky blankets and soft toys. Plus they seem more gross to clean when they get covered in bodily fluids.

Clothes that look like adult clothes. It's so difficult to squeeze baby thighs into miniature corduroys or denim jeans which have no give to the fabric.

Baby washcloths. Babies make a disproportionate amount of mess so you need adult size washcloths to clean them up.



Things that were super useful:

A folding changing mat. I have a SkipHop one which has enough storage for wipes and diapers, which was all I needed to carry with me when I had a newborn. Now that he's bigger, I appreciate the larger size of the mat because the one that came with my diaper bag is way too small.

Balls. They were the first thing he played with and still his favourite toys. At the beginning he liked one made by Oball which was easy to pick up, and a soft fabric one which made a crinkly noise. Now he loves throwing a soft rubber ball and watching it bounce.


Postpartum issues: things that can go wrong after

Wed Aug 9 5:24 PM by rowan in Pregnancy & Parenting

ugh that totes doesn't just happen during c-section. I had a friend who found out when she was having (other) surgery years later and they stitched her up since "they were in there anyway". Honestly I think I also have it but it doesn't cause problems *most* of the time (sometimes stabby pain but no one takes it seriously so idk).


Just Can't Let It Go

Wed Jul 26 1:18 AM by Taurwen in Pregnancy & Parenting

We didn't find out specifically because we didn't want a lot of pink stuff if it was a girl.



Somehow MIL has still given us a ton of pink clothing that she'll change him into everytime she comes over.

I hate pink.


Another baby stars

Thu Jun 15 6:54 AM by StarsInUrEye in Pregnancy & Parenting

Thanks for the congratulations and encouragement.



I had an appointment with the obgyn today. He seems to think I'm even farther along than he originally thought. I didn't have an ultrasound. He just went by the size of my uterus. It's well over my belly button now. He's sending me to a high risk Dr. Asap and then I'm suppost to see him again on the 29th. By then he said they will have a better idea as to how far along I actually am. So far the pregnancy is going well. I did have complications with my first one and went to a specialist but this time I'm being referred to one because I'm old lol. They automatically send women when they are 35 and older.


What did I just say?

Wed Mar 15 12:25 PM by mariareese in Pregnancy & Parenting

Looking to know about the system and biology :D hehe ..


Activities for 1-3 yo's

Sat Jan 14 7:07 PM by antfancier in Pregnancy & Parenting

I find theimaginationtree.com has lots of inspiring ideas. Some look like they take quite a bit of prep, but if you're doing it for a whole class then it might be worth it. You can sort activities by age as well so it's easier to search.


How to deal with opinionated toddlers (or babies or kids)

Tue Aug 1 1:57 AM by rowan in Pregnancy & Parenting

Ooof. My kid is very social, needs to be around someone all the time. It's ... challenging, as you've found. It does get better as they gain their own interests. But it took a long time to get past clingy.



Not having read your post, but just the heading, my response was "wine." But after reading your post, I thought "wine."

Yes. After bedtime.



Also, honestly the only way we made it through was we would take turns being the center of focus. We still do this, divide and conquer (and she's only one kid, hell). Also, I know people are like really limit screen time BUT if you really need to get something done one episode of e.g. Daniel Tiger or Paw Patrol or whatever isn't gonna be too bad. I think DarkOne has some good ideas too.



Good luck.


Happiest Baby on the Block

Wed Jul 12 4:52 PM by antfancier in Pregnancy & Parenting

My mum gave me 'Your Baby and Child' by Penelope Leach, which is what she used when she had me. It covers from birth to five years. I read the first section about newborns in preparation. After having the baby, I realised I have zero time or brain power to do anything so I never got around to the rest of it. In general, I liked the book though. It's a simple overview and has nice color photos.


To all Moms: Where do you go for financial concerns?

Tue May 9 4:18 PM by rowan in Pregnancy & Parenting

My father in law does financial advising so we kind of have an in-house advisor? But seriously someone with expertise is great. There are various "how to do finances" through our local community ed, which I'd probably consider if I didn't already have someone to ask. Maybe something like that near you? Libraries also sometimes have programs.



Also I know you can do wills and stuff on your own but honestly I found it super useful to talk through it with a lawyer who does that. She thought of things we never would have. (hm really should revisit now that kid is older) It was a one time fee and not that bad.



We do most of our banking through a credit union. Have been happy with them. We refinanced our mortgage through them when we did that. I remember the big credit union bust ages ago, but there are lots more protections in place now and big banks can be pretty awful.


stuffed animals

Thu Feb 23 1:20 AM by antfancier in Pregnancy & Parenting

My brother's favorite stuffed animal was a thing we called 'gerbil'. I actually don't know what it was because we found it in the street (not sure what my mum was thinking in allowing him to pick it up, let alone keep it) and it had already lost an eye and was unidentifiable, but he became really attached to it. We almost missed a flight once because he dropped it in the airport and we had to go back to look for it.



Today for the first time my 11month old showed interest in a stuffed animal. Just before Christmas we received a box from Amazon with a giant bear inside. No gift wrap, no note. Just a bear the size of my child. It's been sat in his room and ignored completely, despite him exploring literally everything else that is in there. Then, out of the blue, he made a beeline for it and tried to pull its eyes out.


tactile stuff

Wed Jan 4 6:14 AM by Neko in Pregnancy & Parenting

All the pliable/crafty stuff I can think of has been mentioned. ETA: I lied. Bread dough!



But if generally tactile surfaces also apply, mermaid sequin pillows are comforting. It was one of my impulse buys at a department store about a month ago. I couldn't stop petting the display. The sequined side seemed like it wouldn't be comfortable to rest on but it hasn't been an issue. My stepdad really likes them so I got him one for giftmas and he said it helps distract him when chronic pain keeps him awake at night. https://www.etsy.com/listing/470423508/dragon-mermaid-reversible-luxury-sequin?ref=shop_home_active_40



I haven't field tested them on my nieces and nephews yet. That could be fun.