Genesis 16:1 New English Translation

16 Now Sarai,^[a] Abram’s wife, had not given birth to any children,^[b] but she had an Egyptian servant^[c] named Hagar.^[d]

Genesis 16:1 tn The disjunctive clause signals the beginning of a new episode in the story.
Genesis 16:1 sn On the cultural background of the story of Sarai’s childlessness see J. Van Seters, “The Problem of Childlessness in Near Eastern Law and the Patriarchs of Israel,” JBL 87 (1968): 401-8.
Genesis 16:1 tn The Hebrew term שִׁפְחָה (shifkhah, translated “servant” here and in vv. 2, 3, 5, 6, and 8) refers to a menial female servant.
Genesis 16:1 sn The passage records the birth of Ishmael to Abram through an Egyptian woman. The story illustrates the limits of Abram’s faith as he tries to obtain a son through social custom. The barrenness of Sarai poses a challenge to Abram’s faith, just as the famine did in chap. 12. As in chap. 12, an Egyptian figures prominently. (Perhaps Hagar was obtained as a slave during Abram’s stay in Egypt.)

New English Translation (NET)