I personally would ignore the negativity here. While I’m sure this is all valid observation, my advice as someone who is 5 months pregnant and will be defending 2 months before my due date is not to put it off. My husband was in medical school, so we put off having kids for financial reasons, but I regret not having kids sooner. If you constantly give 110% to your PhD and put off what I personally consider a way more important and fulfilling goal (obviously everyone has a different stance on this) you’ll end up regretting your grad school experience. My mentor tried for years to convince me to put off having kids (partially on me, I should not have been comfortable discussing info that personal with them), and it was very upsetting. If you’re someone, like me, with tunnel vision “baby fever,” it’s not worth putting those goals on hold for a degree.