The past tense of throw the baby out with the bath water is threw the baby out with the bath water.
The third-person singular simple present indicative form of throw the baby out with the bath water is throws the baby out with the bath water.
The present participle of throw the baby out with the bath water is throwing the baby out with the bath water.
The past participle of throw the baby out with the bath water is thrown the baby out with the bath water.