Super agree the following statement from wongnysw:
"小朋友大得好快, 成長一生人只得一次, 第一次叫媽媽爸爸, 第一次自己食飯, 第一次自己上廁所........ 錯過左就無架啦.
做份工做得幾咁成功, 榮耀都是上司、老闆or公司的"
I am not an agressive and career mind woman so that it seems very natural for me to resign after gave birth of my baby.
Anyway, it mainly depends on your own personality. If you really enjoy your career life and feel very boring on taking care of baby, then may be you can choose continue your job and find a helper to take care of the baby.