They summoned the goddess Yogamaya and experienced her transfer the fetus from your womb of Devaki into the womb of Rohini (Vasudeva's other wife who lived together with her sister Yashoda through the river Yamuna, inside the village of cowherds at Gokulam). So the child conceived in one womb was https://digitalasset.blob.core.windows.net/digitalassets/SouthernCaliforniaSurrogacy/Becoming-A-Surrogate-In-Southern-California.html