Based on the night InuYasha and Kagome's child was born... Masaru.
Kagome labor was hard, but she was able to hear her child cries after a long waiting. At first Inuyasha was scared of the fact of being a father, but after holding his own on his arms, all fears vanished. Even later that very same night, Masaru started crying again but Inuyasha gently picked him up and held him close. When Kagome saw it, all she could was cry of happiness for her family.
Inuyasha and Kagome (c) Rumiko Takahashi
Masaru (c) Noble-Maiden