Some of these backpacks/rucksacks are still in production, while others will have to be found used or old-stock.
Popular alternatives to
Cole Haan Hermitage Backpack
AZMED Maternity Belly Band for Pregnant Women | Pregnancy Belly Support Band for Abdomen, Pelvic, Waist, & Back Pain | Adjustable Maternity Belt | For All Stages of Pregnancy & Postpartum (Beige)