DCDA twins can be fraternal (two eggs, two sperm) or identical (one egg, one sperm). All fraternal twins will be DCDA, while identical twins can be DCDA, MCDA or MCMA depending on the stage when the blastocyst splits.
If your twins are identical, then the odds of having another set of twins is the same as any other pregnancy because identical twins are a random fluke of nature.
If your twins are fraternal, then you have proved yourself to have released two eggs on at least one occasion. The odds of twins again is therefore increased, as the chances of you releasing two eggs is higher than in someone who we don't know to have released two eggs on any occasion.
When I was pregnant with my twins, I heard that there is a 1:89 chance of fraternal twins in a normal pregnancy, with a 1:4 chance of fraternal twins for a mother who already has fraternal twins. I think I read it in "Your Pregnancy Week by Week" by Lesley Ragan, who is a mother of twins herself, but I can't be certain that was the source.
Anecdotally, my second pregnancy was a single baby
Fraternal twins here, yes I remember now if the egg splits in the first couple of days identical twins can still be DCDA, I think there was so much info to take in at the time it all went a bit over my head.
That's a lot higher than I thought it would be!! I wouldn't mind having twins again at all, or a singleton, but perhaps would wait a little longer until these two are slightly older before trying again - I imagine the logistics of two sets of twins under 3/4 would be tricky.
is there a logic to the 1:4 chance, or is it based on observation? I had fraternal twins and GP poopoohed the notion that my next pg might be twins, despite the fact that every other person I spoke to had a cousin who had twins and then went on to have triplets. He did send me for an early scan though, bless him.
Well yes, plus the fact that your first set of fraternal twins might indicate that you have a genetic predisposition to release multiple ova. That’s why a woman with previous fraternal twins have a higher chance than a woman of the same age with previous single pregnancies.
I'm mid 20s and not a twin myself, there were lots of twins further up the family tree but no record of any subsequent siblings for any - not sure if there were any and the family tree isn't accurate or not.
It's all very interesting stuff thank you for your input!
"If your twins are identical, then the odds of having another set of twins is the same as any other pregnancy because identical twins are a random fluke of nature."
Not relevant to the OP, but actually the likelihood of having monozygotic ("identical") twins is probably weakly heritable as well. Research is currently ongoing, but some populations and families have usually large numbers of identical twins, suggesting that there may be a genetic predisposition towards the splitting of blastocysts in some women.