Why are babies overdue?

[lozzenge]

My son was born on the 7thJanuary 2009 but his due date went from 25th December to 1st of January. Could the lmp be wrong or do babies speed up and slow down through the trimester's?

The World Health Organisation considers anything between 37 and 42 weeks to be normal gestation. We, on the other hand, are given the message that anything over 40 weeks is abnormal. It just depends on the individual woman and her baby. Some need a bit longer than others.

Ovulation is not an exact science. I know I tend to ovulate on the 21st day of my cycle. But with pregnancy all the professionals want to count it from the 14th.

I don't know if every person has exactly the same gestation period either. Some people can have huge healthy bouncers at 36 weeks and others can have babies who are health/size wise preemies at full term.

Also it is bloody cold at that time of year and baby probably just wanted to stay nice and warm.

I think its usually because they have got the dating scan measurement slightly wrong.

Ovulation is not an exact science, I am usualy regular as clockwork and with my 2 dc's I was never asked the length of my cycle this pregnancy I have been and they have adjusted the due date accordingly got my scan next week so we will see how close a date I get from that.
Also the dating scan is not 100% exact science either it is near enough but obviously there will be margins for error.
And like someone else said some people just cook them longer.
Both mine were 2 and 3 weeks early and reasonable sized healthy babies but a friend of mine was induced on her due date because they thought her baby was huge and it turned out to be a tiny scrap of a thing.

i don't think technically, many babies are

a normal, full term pregnancy can be anywhere btween 37 and 42 weeks, so you're not really overdue until 42 + 1

however, most women are offered a membrane sweep and then an induction around term + 10 or 12, so few babies get to post 42 weeks

some women have longer cycles , others have shorter

the EDD is just that, estimated.

your baby can be born weeks before or after the EDD

it is just a guide, but we tend to get hing up on it as the absolute date

the dating scans are a bit hit and miss too - some babies are bigger or smaller than others and sometimes the measurements aren't completely accurate. I was initially told my babe was 10+3 at first scan and I said I was 100% re date and was definitely 11 weeks so they checked again and it was 11+2 - babe was v active so probably affected accuracy. One of my friends had her date changed because head was narrow but her and her dp have narrow heads so baby is hardly going to have a wide one. My 2 were both 42 weeks - they kept saying DD was due on 22nd but my dates were 9th and I was sure - when she came on 22nd she was clearly post dates - v dry skin and long nails. Sometimes think they fiddle with dates to make them feel they have a role at a stage in pregnancy when nature is in total control