These should be all the status effects that you can keep outside of cutscene. Most of them are easy to find (like Semen Buildup and Pregnant). I will just list the one that are less intuitive to locate:
Tentacle Egg Cluster and Mucus: got swallowed by worms in Innard Cave and travel all the way down its intestine.
Aroused and Parasite: infected villagers, available after defeated by village's priest during initial encounter.
Flesh Bud: tutorial boss.
Leech eggs: blue leech that shoot projectiles in swamp.
Cursed Seed: tree boss.
Enlarged Breasts and Lactation: pigman boss or use the item you receive from the bridge boss.
Womb crest: cultists at Cathedral.
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