。
The due date is around mid-January.
Literal
Scheduled-day [topic-は] January-[genitive-の] mid-part approximately is-[polite-です].
中旬 ('middle ten days of the month') is one of a trio — 上旬 (first third), 中旬 (middle third), 下旬 (last third) — used to divide a month into rough thirds without naming specific dates. 頃 ('around, about') is a soft-rounding suffix for time expressions. 予定日 ('scheduled day') often refers to the expected date of a planned event, including a baby's due date.