Menstrual cycle length and pregnancy length

[zambean]

I read somewhere that there may be a link between the length of your normal menstrual cycle and the length of your pregnancy, so that women with shorter cycles might be more likely to give birth before or on their due date, and women with longer cycles might be more likely to go past their due date.

I've no idea if there is any truth in this, but I'm currently 31 weeks pregnant, and normally have a 22 day cycle, so I'm certainly intrigued to see if this means my baby may come early! And while I know the plural of anecdote is not data, I'd be interested to see if that bears out here!

So, for all who've had babies before:

How long is your cycle normally?
When did your baby arrive?

Not much help as I was induced but my induction worked very quickly as apparently I was 'ready'

28 days
39+6

25 days and I had my son at 36 weeks.

Interesting theory, was there any reason given for a connection between the two?

Spanner in the works

I didn't have periods.

DS was born 39 + 4

26-39 days, dts born at 31+3

I had slightly longer than average cycles (29/30 days), and all of mine were at least two days late.

The key thing is probably when you ovulate. Calculation of due date is based on ovulation being 14 days after the first day of your period, so if, like I did, you ovulate on day 16 or 17, you will be told that you are due two or three days before you actually are.

And if, like I did, you grow mahoosive babies, you may well be told that you are due earlier again: one, by my sums from date of ovulation, was due on the 10th; by LMP, due on the 8th; by scan, due on the 6th. Huge baby, who would have been induced had I not known the date of conception, and had the wonderful community midwives not rallied round and told the hospital to leave me alone, it was all fine.

I did ask about the scan thing, btw: I said to the sonographer, how do you date the foetus? By the length of the femur, she said. Well, I said, since I have massive babies, surely mine will have longer femurs at the same age compared to smaller babies. Tsk, I was told, makes no difference. But I can't see how it couldn't. Any monographers out there who can enlighten me?

Cycle length 23-24 days

First baby: 41w
Second baby: 41+3
Third baby was a scheduled caesarean and thus early; otherwise I dread to think how long he'd have stayed in!

No correlation for me.

Lumela I think sonographers get it wrong and 'backdate' the pregnancy if the baby is too big. With my first two I was actively ttc and very sure about dates. With both I had an early scan (7ish weeks) which confirmed dates. Suddenly at the 12 week scan was told I was a week further along which I think was just BS! They had simply started growing bigger already.

Averaged around 29 days.

Ds1 42 weeks
Ds2 40
Ds3 38
Ds4 34
Dd1 31

Not much to go by there lol.

28 days
42 weeks (had to be induced).

My cycle is a very regular 28 days.

I had two DC born at 39 weeks and the other at 40 weeks.

I think the idea with dating is that during 1st trimester the baby follows a fairly standard growth pattern, it's after then that genetics take effect so dating is less accurate - eg if you are tall then those genes would have come into play and baby would be measuring big. Obviously it doesn't always work though as plenty of people know the date of conception and due date given doesn't match.

I don't think so, my cycles are generally 30-33 days with maybe 2 shorter 28 or 29 day cycles per year. My dc arrived at 37, 35+2, 39+4 & 38+5. All spontaneous labours, dc3&4 had a long latent phase.