there are a number of maternity patterns out there by Simplicity, McCalls, and Butterick. But most of them don't go up to higher plus sizes, stopping instead at a size 16 (which is more like a 12-14 in ready-to-wear) or at most an 18-20. Fine if you fall into that size range, but zaftig pregnant women are left with few options.
Well, if you're like me, you probably have one or two patterns that you always reach for when you go to sew a shirt or pants -- ones that you know will fit and give you the results you want. Now you can use those patterns as a basis for simple maternity wear, without having to buy new ones that will probably not fit (trust me, I know from experience!).
This method works best for very easy patterns, where the front and back pieces
are cut on the foldline. It could be used for front-button shirts as well, but
I can't guarantee how it will look. It is also best for sewing with knits and
fabrics that have some stretch. It's really quite simple, though. Just place
the front piece at an angle to the foldline, as shown at right:
When you cut the piece out, curve the front hemline slightly,
so it's not angular. The front and back pieces will be sewn as you normally would,
and there will be some extra room just in front, where you'll need it most. You
can vary the angle depending on how big your belly is; smaller bellies will need
a smaller angle, while bigger bellies can use a larger one.
You can use the same method for straight and A-line dresses, although if they are very long, you may run out of fabric width before you get to the hem! In this case, you might consider adding a gore to the skirt... but that's another story, and not one I'll attempt to explain here.
Pants are usually a little more finicky than shirts are, but this method should get you through a few more months of pregnancy, if not the whole of the last trimester (depending on how big you get). This is meant for pants with elastic waistbands and drawstrings. If your fabric has a little give to it, so much the better.
I
found that I wanted my pants' waistbands to go above my bump, and that they were
most comfortable when they sat right about at the base of my ribs. So I added
a few inches to the waistband. I also needed a little more room in the belly,
but didn't want to add it to the hips when what I needed was room in the front.
This part is pretty tricky, and I would recommend playing with some muslin before
committing pattern changes to your fashion fabric -- you will probably need to
cut and sew several times to get the right fit. Basically, it's a matter of finding
out where your "bump" starts in your rise ( the distance between your mid-lower
back and the front waistband, going between your legs). That's where you'll want
to put the other addition. The darker orange segments in the drawing indicate
additions to the pattern, while the lighter yellow indications the original pattern.