The most important question I was trying to answer with the survey was this: "When is a baby most likely to spontaneously show up?" The graph above shows the percentages, based on 5973 responses. 4508 of the deliveries were as a result of labor occuring spontaneously. The chart only shows these deliveries, which is why the percentages do not add up to 100%, because only 75% of participants had spontaneous (non-induced) labor.This page shows what day you'll likely give birth, if you're still pregnant at 38 weeks. To find out how week 38 compares to the other weeks overall or to find out the probability of delivery at 38 weeks, refer to the Length of pregnancy by week chart.
The statistics right now are as follows:
|Day||Week||Births||Running Total||Percent||Running Total %|
|266||38W,0D||74||74||1.2 %||1.2 %|
|267||38W,1D||67||141||1.1 %||2.4 %|
|268||38W,2D||68||209||1.1 %||3.5 %|
|269||38W,3D||108||317||1.8 %||5.3 %|
|270||38W,4D||124||441||2.1 %||7.4 %|
|271||38W,5D||127||568||2.1 %||9.5 %|
|272||38W,6D||133||701||2.2 %||11.7 %|
|273||39W,0D||159||860||2.7 %||14.4 %|
|274||39W,1D||141||1001||2.4 %||16.8 %|
|275||39W,2D||146||1147||2.4 %||19.2 %|
|276||39W,3D||210||1357||3.5 %||22.7 %|
|277||39W,4D||205||1562||3.4 %||26.2 %|
|278||39W,5D||211||1773||3.5 %||29.7 %|
|279||39W,6D||256||2029||4.3 %||34 %|
|280||40W,0D||257||2286||4.3 %||38.3 %|
|281||40W,1D||253||2539||4.2 %||42.5 %|
|282||40W,2D||231||2770||3.9 %||46.4 %|
|283||40W,3D||208||2978||3.5 %||49.9 %|
|284||40W,4D||196||3174||3.3 %||53.1 %|
|285||40W,5D||209||3383||3.5 %||56.6 %|
|286||40W,6D||197||3580||3.3 %||59.9 %|
|287||41W,0D||206||3786||3.4 %||63.4 %|
|288||41W,1D||148||3934||2.5 %||65.9 %|
|289||41W,2D||116||4050||1.9 %||67.8 %|
|290||41W,3D||118||4168||2 %||69.8 %|
|291||41W,4D||92||4260||1.5 %||71.3 %|
|292||41W,5D||73||4333||1.2 %||72.5 %|
|293||41W,6D||59||4392||1 %||73.5 %|
|294||42W,0D||47||4439||0.8 %||74.3 %|
|295||42W,1D||20||4459||0.3 %||74.7 %|
|296||42W,2D||18||4477||0.3 %||75 %|
|297||42W,3D||8||4485||0.1 %||75.1 %|
|298||42W,4D||9||4494||0.2 %||75.2 %|
|299||42W,5D||6||4500||0.1 %||75.3 %|
|300||42W,6D||1||4501||0 %||75.4 %|
|301||43W,0D||7||4508||0.1 %||75.5 %|
Due Date Survey DataDue date statistics: A study on the length of pregnancy
Probability of delivery resulting from spontaneous labor after 38 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?
Survey input dates
More ResourcesPregnancy Day-by-Day
Fast pregnancy calendar
Baby age calendar
EDD Icon Generator
Jo's Birth Story
Weeks vs. Months Explained
Charts generated by flot