I did it, after DS3, 4 & 5!!
I had PND after DS2. It was a combination of 11 month age gap, baby had lactose intolerance (undiscovered until 4 months old) and a mmc (after taking morning after pill). It all got to much for me and I was put on "happy pills" for a year or so. I came off them when pg with DS3 but was very up and down throughout the pregnancy.
My Doctor (woman) was a specialist in womens health and recommended I use Oestrogen patches after DS3 to combat PND. I had to put them on within 3 days of giving birth and wore them for about 3 months in total. It made such a difference. I know it worked as when DS3 was 8 weeks old I stopped using them and took a nose-dive. So I continued for a while longer.
I had a fight getting them after DS4 & DS5 however as I had moved and it is very controversial in the UK. Have never heard of anyone else having been offered them. I am a determined lady though, lol!!
I used them for shorter times after each baby and not at all with DS6. I never felt any sickness whatsoever and I breezed through the 3 day baby blues. Some people don't react so well to a dip in hormones. That little help was a godsend!
HTH, xxx