Uttara was pregnant when Abhimanyu went to war. How many years they lived together?
Brahmam, the Supreme Creator (Narayana) created Brahma Deva. From Brahma's right Chest, appeared Dharma Deva.
Dharma Deva had 8 sons named as generally as Vasu.
One Vasu named "Soma" whose father is Dharma Deva and Mother is Manasvini, had son named "Varchas"
When all the Asura took the form of humans and conquered the Human World (earth), Brahmam (Supreme Creator) decided to incarnate himself as Krishna.
Hearing this news, all Deva started to incarnate themselves in Human Form.
At that time, Soma (one of Vasu) hesitated to let his son "Varchas" to born as Human.
He told the other Devas as following:
नाहं दद्यां प्रियं पुत्रं मम प्राणैर्गरीयसम्।
समयः क्रियतामेष न शक्यम् अतिवर्तितुम्।।
सुरकार्यं हि नः कार्यमसुराणां क्षितौ वधः।
तत्र यास्यत्ययं वर्चा न च स्थास्यति वै चिरम्।।
ऐन्द्रिर्नरस्तु भविता यस्य नारायणः सखा।
सोर्जुनेत्यभिविख्यातः पाण्डोः पुत्रः प्रतापवान्।।
तस्यायं भविता पुत्रो बालो भुवि महारथः।
ततः षोडशवर्षाणि स्थास्यत्यमरसत्तमाः।।
अस्य षोडशवर्षस्य स सङ्ग्रामो भविष्यति।
यत्रांशा वः करिष्यन्ति कर्म वीरनिषूदनम्।।
नरनारायणाभ्यां तु स सङ्ग्रामो विनाकृतः।
चक्रव्यूहं समास्थाय योधयिष्यन्ति वःसुराः।।
विमुखाञ्छात्रवान्सर्वान्कारयिष्यति मे सुतः।
बालः प्रविश्य च व्यूहमभेद्यं विचरिष्यति।।
महारथानां वीराणां कदनं च करिष्यति।
सर्वेषामेव शत्रूणां चतुर्थांशं नयिष्यति।।
दिनार्धेन महाबाहुः प्रेतराजपुरं प्रति।
ततो महारथैर्वीरैः समेत्य बहुशो रणे।।
दिनक्षये महाबाहुर्मया भूयः समेष्यति।
एकं वंशकरं पुत्रं वीरं वै जनयिष्यति।
प्रनष्टं भारतं वंशं स भूयो धारयिष्यति।।
- adi parva (vyasa mahabharata)
"My son is dearer to me than all living beings. I will not give him away. You must accept the fate I am about to tell you. I agree that, It is our business to kill the demons incarnated on earth. My son 'Varchas' is going to be born for this. But he will not stay on earth for long.
May he be born as the son of Nara, the consort of Narayana. While he is Young boy, a Great Warrior, O best of Gods! My child will be in the world for only 16 years.
At that age, a great war between us and the Asuras will take place in the world. The Asuras will set up a cycle and fight. My child will roam inside without being able to break the cycle. He will turn his back on the enemies standing there and run away. There alone, my son will will send one-fourth of the asura army to their own city. Many great warrior will join together and fight with him. Finally, i will get him back again in the same evening to my place. He will give this dynasty a valiant son. That son will restore the lost dynasty of Bharata," he said to the other gods
After the end of war, gandhari along with her husband, vyasa, pandava, krishna visits the war zone.
Vyasa gives gandhari divine vision to see things despite she closed her eyes with silk cloth.
At that time, she sees uttara crying over Abimanyu who was killed by multiple warriors at same time.
Uttara cries...
एतावान् इह संवासॊ विहितस् ते मया सह |
षण् मासान् सप्तमे मासि त्वं वीर निधनं गतः ||
- vyasa Mahabharata (ஸ்திரீ பர்வா)
The union with me in this world had it seems only for 6 months, for in the 7th O hero! You have bereft of life.
இவ்வுலகில் என்னுடன் உமக்கு இந்த 6 மாத காலம் தான் வாழ்க்கை ஏற்படுத்தப்பட்டது. 7வது மாதத்தில் நீர் வீரமரணத்தை அடைந்து விட்டீர்.
Uttara later gave birth a son named "Vishnu RAthan" alias "Parikshit".
Parikshit ruled the entire world with no enemies around, inherited from his grandfather "Yudhistra".