In 1725 her husband was in Constantinople and then to the Persian frontier to the disengagement .
Mary remained in Moscow and gave birth to a fourth child , a son , baptized in honor of Tsar Peter Alexandrovich .
In 1725 her husband was in Constantinople and then to the Persian frontier to the disengagement , but Mary remained in Moscow and gave birth to a fourth child , a son , baptized in honor of Tsar Peter Alexandrovich .