Why are subsequent babies so unlikely to engage before labour??

[merryberry]

What's the physiology and anatomy behind this??

Everything I read casually mentions that first babies tend to engage around 37 weeks, giving that lovely 'lightening' where you get less heartburn, indigestion and rib pain (though you may get achier pelvis and back....)

And that subsequent babies generally don't engage until active labour commences. So there is no relief until B-day.

Why oh why oh why oh why would this be?

It is a huge disappointment to me that I'm likely to carry high to the end of PG, I loved lightening last time round!

presumably it's to help stop you going into premature labour as your cervix never fully closes after its first labour?

oooooooh, interesting idea! thank you.

that is a complete guess btw I have zero medical knowledge

anyone else have any ideas?

I thought it was that the muscles in that area were less toned so the baby's head can bob in and out without becoming engaged?