I was an academic. DH still is.
My 3 pregnancies were difficult (hyperemesis) and I lost a lot of time and, worst of all, there was a lot of time when I wasn't off work but wasn't working at anything like full capacity due to all the sickness and it is difficult to get medical certification for that.
DH and I agreed that once my maternity leaves were over his career would take a back seat and he could catch up.
That time arrived, they were closing departments like his all over the place, his research had inevitably been affected by the children and sickness too, so we found ourselves in a position where not only was my career very uncertain, but if we risked him doing any less work than he had been doing, his could go down the tubes as well.
So I've been at home for nearly 4 years now and his is nearly back up to speed again
It makes me laugh, when I was at school a Very Successful Woman Scientist came to speech day. She told us about how lucky she had been to successfully manage career and family (she was really lovely and actually quite subversive because the message our school wanted to give us was that we would all do everything.) She explained that she was only able to do this because her dh had already got established in his field so he really could take a back seat and do the childcare once the babies came along.
I only later found out who her dh was. He was Ernst Chain and when she said his career was established by the time they had kids, she meant he had got the Nobel Prize for the discovery of penicillin 