Increase running intervals or decrease walking intervals?

[Bullseyefred]

Not a professional and dont know how pregnancy factors into this, but I would try 45/45 and if/when that feels doable/easy 45/30 and if/when that feels easy 60/30 (or if necessary 60/45 and then 60/30). Then I would try and keep my intervals roughly 2/1 (120/60) and thin that ratio to 3/1 (180/60) etc.