A halloween costume, a prom dress, and really anything from Forever 21 are considered disposable. You wear them once or twice and you're pretty much done with them. Buying ready-to-wear slacks 2 sizes bigger than you normally wear when you are more than 17 weeks pregnant is pretty much a wear it once or twice "investment" as well...therefore disposable. I put investment in quotation marks because so many mommies (yours truly included), think "I can wear it after I have the baby" or "it's on clearance and it works"....so you think but only for a wear or two. But the reality (for most but not all) is that you won't be two sizes bigger in ready-to-wear after you have the baby and/or it will be the wrong season. And with all that aside, it's just down right uncomfortable and you run the risk of looking like a hot mess with the pant crotch hanging mid-thigh.
Well-made maternity clothes should NOT be considered disposable. Yes, there will be pieces you will despise once you have your baby but there will be some that you absolutely love and will remain in your wardrobe for a very long time! Instead maternity clothes should be in the Temporary category. They are clothes you really need to hold up during many many wears during your pregnancy....and for a few months postpartum too. So let me stress WELL-MADE. Cheap maternity clothes are actually considered more disposable because they likely won't last after one or two spin cycles. A much better investment is a well-made pair of maternity slacks for 59 or 69 bucks that you can start wearing earlier on, machine wash, and be comfortable. Don't get me wrong, I'm not bashing all inexpensive maternity clothes. Tank tops for 10 bucks, shorts for 20 and sundresses for 30....they are fine. Those are all supplemental pieces compared to your staple black pants, a great pencil or a-line skirt, and denim which should all be built for a lot of wear and designed to grow with your belly. That's what determines the difference between temporary and disposable. Temporary...built strong. Disposable...overall bad investment.