Referring the question to Sheikh `Abdel Khaliq Hasan Ash-Shareef, an eminent Muslim scholar and Da`iyah,
No, this is not permissible. A one-year old child can eat and drink by itself if weaned. Moreover, pregnancy does not prevent from work, and many pregnant women go to their works everyday.
After all, Allah is the All-provider and All-Sustainer, and He has given this blessing in the form of a child. So, a Muslim should not refuse His blessing. This case is not a case of necessity.