# Probability of delivery within x days of a given date

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This graph shows only babies born as a result of spontaneous (non-induced) labor (76% of all participants).

Do babies come on their due dates? Not really. But they seem to come around their due dates. In the survey, only 654 out of 14664 (4.5%) spontaneously arrived on the exact day. But if you look around that date, the numbers get bigger fast... 3612 babies (24.6%) arrived spontaneously between 39 weeks 4 days and 40 weeks 3 days. 6864 (46.8%) arrived spontaneously within a week of their due date. Throwing out inductions makes those percentages even higher: 61.5% of all non-induced babies arrived within a week of their due date.

I also think this graph is important because it shows how meaningless it is to move a due date one or two days. For example I have a chart comparing first time moms to mothers who've had previous births, and it shows about a 1-2 day difference. But based on this graph, who cares about a day?

What I mean is this: a woman who's not induced has a 61.5% chance of giving birth within a week of her due date. Let's say we lie to her and tell her a date that's three days early. Now she has a 60.7% chance of delivering within a week of that "wrong" date. It's not really a huge difference.

### Data Table

DayIn weeksBabies Spontaneously Born
24535W,0D21
24635W,1D21
24735W,2D20
24835W,3D25
24935W,4D24
25035W,5D26
25135W,6D22
25236W,0D44
25336W,1D30
25436W,2D42
25536W,3D46
25636W,4D36
25736W,5D46
25836W,6D58
25937W,0D86
26037W,1D78
26137W,2D81
26237W,3D93
26337W,4D114
26437W,5D111
26537W,6D145
26638W,0D172
26738W,1D154
26838W,2D168
26938W,3D214
27038W,4D273
27138W,5D248
27238W,6D291
27339W,0D351
27439W,1D319
27539W,2D330
27639W,3D428
27739W,4D446
27839W,5D447
27939W,6D511
28040W,0D654
28140W,1D582
28240W,2D506
28340W,3D466
28440W,4D427
28540W,5D472
28640W,6D464
28741W,0D461
28841W,1D356
28941W,2D280
29041W,3D274
29141W,4D192
29241W,5D142
29341W,6D122
29442W,0D89
29542W,1D40
29642W,2D31
29742W,3D27
29842W,4D13
29942W,5D11
30042W,6D10
30143W,0D12

### 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?
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

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.

Sat Feb 2 11:42 AM by melsbells in Pregnancy & Parenting

Spacefem, thanks for the book suggestions.

Sonic, I like the way you described the sound a letter makes.

I asked a few early elementary school teachers I know this same question and wanted to share a bit of what they had to say.

They recommended starting with consonant-vowel-consonant words (CVC) with short vowel sounds, and focus on rhyming families (i.e. bat, cat, fat) and even including first consonant changes that don't make real words, like 'gat'. Then later introduce CVC with last letter changes (i.e. bad, bar, bat). They said we could try sight words at the same time and told me to do a search for the Fry sight word list.

After those CVC words aren't a problem, it was suggested to start adding an 'e' at the end of CVC words to change the vowel sound, an the meaning of the words, so introducing long vowels (i.e. cap->cape). Then after all that, we can start adding two consonants together and two vowels together. From there maybe come up with homonyms together, which can be a great way to introduce silent letters (i.e. new, knew).

### How important is school?

Thu Nov 22 9:05 PM by Skeezy in Pregnancy & Parenting

I think the most important factor in any school is how much the teachers care about the students. Another important element is safety and how interactions between students can substract from learning. Many parents go to jail for quite lengthy sentences for trying to send to their kids to a safe good school.

I would say its very important, because what you learn shapes and molds yours views that make you who you are.

### Unplanned, polyamorous pregnancy situation

Sun Apr 29 12:18 PM by metawidget in Pregnancy & Parenting

I'm glad you have been communicating and working things out. I wish you lots of health and love as you wrote the next chapter of this story.

### I might be pregnant...

Fri Jan 5 3:16 AM by Aum in Pregnancy & Parenting

Aum, my partner and I were just discussing this. He was surprised by my taking the hard line that stopping BC or poking holes in condoms or something like that is rape, making the woman a rapist. Which should result in jail time, so she should lose custody, which should go to the father and now he has the choice of keeping the baby or putting them up for adoption.

It's unfortunate that you can't prove such a thing, but hopefully if it was actually taken seriously women would be less likely to do it because it would at least be explicitly called rape.

I understand how the justice system and the family courts would look at it. They see it as the man's sperm made it to the egg so somehow he wasn't protecting himself, he made the choice, yada yada. There's no way to prove that the woman was manipulative, withdrew BC, or "poked holes in the condom" (I think that's unheard of, but anyway).

### When do you outsource parenting?

Sat Oct 14 7:47 PM by rowan in Pregnancy & Parenting

yeah I do a ton of supplemental history... :(

### Sleep for babies after 6 months

Thu Jan 10 1:30 AM by Sonic# in Pregnancy & Parenting

Thank you for the stories. I try not to get caught up in comparisons, but it's so hard when someone else is like, "Oh yeah, they're sleeping through the night after six months, no problem!" and we're nudging each other when it's our turn to get up at night almost every night. Did I do something wrong? (The answer is probably no, but a lack of sleep makes it harder to get there mentally.)

I topped baby off tonight. He straight up drank 7 ounces of formula after his prunes. If he's an infiltrator, he's eating well for it. :)

### How the 2nd pregnancy / labor was different from the first

Thu Sep 27 8:20 PM by antfancier in Pregnancy & Parenting

I haven’t been around for a long time, but I’m back and pregnant again. Only 6 weeks, so I can’t really comment much, but this time around it has been easier so far. Not easy, but considering I’m working and have a 2.5yr old (neither of which applied to last pregnancy), I thought I’d feel much worse. I still have ALL the symptoms and they all started at 3 weeks, just like last time (and the same as a chemical pregnancy I had too) but they don’t seem to be as constant as before. I’m really glad about that! The only thing that’s worse is back ache, ligament pain, general body aches. I assume it’s because my body is already exhausted and broken from my toddler.

### posting pictures of kids and privacy

Wed Apr 25 7:29 AM by juliabonl17 in Pregnancy & Parenting

Usually, we don't share photos of our children in social media. Sometimes I can send some photos to close friends. I keep my personal life in quiet. Share with family only.

### I had my 2nd baby!!!!

Wed Jan 3 8:21 PM by MFS in Pregnancy & Parenting

OMG BABY!

I am still dealing with the fact that your 11 year old is an actual 11 year old.

### on being semi-pregnant

Tue Oct 3 7:18 PM by geldofc in Pregnancy & Parenting

congratulations!! i've never been pregnant but i'm jealous. i'm having baby fever lately.

### kids' mail subscriptions

Wed Jan 9 6:41 PM by melsbells in Pregnancy & Parenting

We got the first box last week. Kid wanted to do the whole thing in one sitting, which was tough. He has a hard time stopping something, even when it's obvious he needs a break. He doesn't have the best conception of time yet either and kept talking about the box that would come tomorrow. So getting something once a month might help pin down the passage of time. As far as my concerns, we had a great opportunity (when he was disappointed that the Europe page didn't say anything about Finland) to talk about how a single page on a whole continent or even an individual country can't tell us what a place and culture is like. Bavaria was mentioned, so we also got to talk about how our German friend feels when people only think of Bavarian things when thinking of Germany, which she doesn't feel a connection to.

### housemates + newborn = ?

Thu Aug 2 11:57 AM by melsbells in Pregnancy & Parenting

I live with my in-laws, and while there will certainly be a lot of differences from your situation, maybe there's enough similarities that my experience could be useful to you. I think the biggest thing is that everyone has their own space. Our house is sort of divided in two, so we can take the kid to our end during a tantrum. I think that distance helps, not just with in-laws not wanting to hear screaming, but as a sort of physical signal for the kid to calm down. We lived in an apartment when the kid was first born and our neighbors there probably heard more screaming/crying due to proximity.

My father-in-law spends a lot of time with the kid, mostly by choice. I sometimes wish we had more of a schedule, because at the moment, naps and bedtime are the only semi-guaranteed breaks for anyone. My spouse and father-in-law both work from home free-lance, so they don't actually have a schedule for when they need to be left alone, but at least my father-in-law has more warning with jobs scheduled out in advance.

### My Ectopic Pregnancy

Tue Jan 23 8:47 PM by rowan in Pregnancy & Parenting

FYI we have a general culture in the pregnancy forum here about sharing similar stories as a way to offer support, and also about giving any medical knowledge that we've come across, since pregnancy is generally not talked about as much as it should be and you find information in random places. Since you haven't been around until now you probably didn't know that, and mels' post is well in line with forum guidelines and norms. Please don't go all mod martyr on us now that you're only just back. This is me as a friend speaking here, not with my modhat on.

I'm sorry for your loss. Ectopic pregnancies are scary, and I would like to go punch that first doctor in the face for you.

PPD is awful too. :( I hope you can get through it.

### gender recognition

Thu Nov 2 1:03 PM by Nech in Pregnancy & Parenting

You can continue discussing with him the difference of a boy and a girl. Have him socialize too with the same gender. There's nothing wrong if you have go with opposite sex as long as he understands what/who he is.

So do you feel hanging out with the opposite gender at a young age can confuse a person's gender identity?

### leftist parenting and gender [split from gender recognition]

Sat Sep 23 11:52 AM by Unvoiced_Apollo in Pregnancy & Parenting

gender recognition.">

If a boy who has a penis asks if he's a boy and you don't just say yes, then that's straight up lunacy.

What he decides to do with that boyhood or how he dresses is up to him. But if you're born with a penis you're a boy.

Making it airy fairy when, statistically, scientifically, less than 1% of 1% of children born have true gender dysphoria, is immoral and wrong. It's also a sign of our troubled times.

This is just my anecdotal experience but...

I have experienced bullying based on simply engaging in normal children's play with girls. Insults were attacks on both me and the girls. But I NEVER questioned my gender as a male. So if a child asks me if he's a boy and was identified biologically as one, I am going to question what influences are on the child before I answer.