Because of this Shaap of Umaa to Devtaa, i.e. celestials, Devtaa cannot have children from their wives. They have to use some other medium to have a child. We have many examples of this in our history - 

--Hanumaan was the son of Pavan (Wind) Dev; 
--Menakaa Apsaraa had her daughter Shakuntaalaa from Vishwaamitra Jee [although Apsaraa are not Devtaa but this applies to them also]
--Urvashee Apsaraa had six sons from Pururaavaa
--Somadaa had Brahmdatt from Rishi ..; 
--all six Paandav were the children of Soorrya Dev (Karn), Dharm Raaj (Yudhishthir), Pavan Dev (Bheem), Indra (Arjun), and Ashwinee Kumaar (Nakul and Sahadev) respectively.

Another Shaap She gave to Earth. The sin of Earth was to bear the semen of Shiv Jee onto her surface. That the appearance of earth will not be uniform and in quality (for it has lands and oceans, deserts and forests, volcanoes and mountains, ice and humidity, etc.). And she will be the wife of many - so the Earth is also the official wife of numerous kings.

The Earth was also cursed not to have the delight of her own children. The Earth has only two children: Narakaasur, the demon and Seetaa Jee as her children. But these two are also not begotten through any seminal contact by Earth; and further, for earth they are as good as not having these them, for such is the plight of these two children of the Earth. After many tumults in her life, even Seetaa asks her mother, the Earth, to take Her back into her womb.
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