It’s been 7 years and 4 babies since I first started sewing myself maternity clothes. At one time, finding maternity clothes that I liked was its own special kind of nightmare. Fortunately, once I learned the basic maternity adjustments, I discovered most sewing patterns can be adjusted for maternity wear.
The difference between maternity and standard sewing patterns is the extra fabric needed to the stomach. To convert a regular pattern into a maternity pattern, it needs accommodate both in the increase in length from the top of the belly around to the bottom of it, and the increase in width around the waist. There are probably as many ways to adjust a pattern to do this than there are pregnant bellies in the world right now. I will be focusing on just 3 ways that I have used to adjust a classic t-shirt pattern. The same principles of maternity adjustments apply when talking about woven tops, but I won’t be addressing those specifically here.
The Starting Point
For a starting point, I used the Cashmerette Concord T-shirt. The Concord is a classic fitting t-shirt that skims the curves of the body which makes it a really great starting point for maternity adjustments. The tutorial assumes you are working with a similar cut of t-shirt, but the same principles apply no matter the maternity pattern. I had already personalized this pattern before my pregnancy (lengthening it to accommodate my height, and grading out to a larger size in the hips) and I won’t be addressing those issues here. The graphic above shows a rough sketch of the original pattern. No changes were made to the sleeves or neckline. Hems and seam allowances are not included.
For reference, I am 5’10” and wear around a size 18 when not pregnant.
Slim-Fit Gathered Front Maternity Adjustment
If you like a close-fitting maternity top that hugs your bump, this is the adjustment for you. It uses negative ease to keep the fabric skimming close over the bump, and has extra length to keep the maternity panel of your maternity pants appropriately covered.
This adjustment uses the “slash-and-spread” technique to add more fabric to the stomach area. Length is added to both the front and the back, but more so to the front. The difference in lengths is brought together as a gather in the side seam.
- On the front pattern piece, cut the pattern at the waist and slide the bottom piece straight down 5 inches from the top piece. Keeping the pieces aligned at the center front fold.
- Fill in between the top and bottom pieces with paper, and smooth out the curve of the side seam between the top and bottom pieces.
- On the back pattern piece, extend the hem down 2 inches.
- When sewing the front and the back bodice together at the side seams, the front is gathered to fit the length of the back.
- I do not add extra width when doing this adjustment because I like the look the negative ease for this type of top. If you need/want more room widthwise, you can “grade out” the side seams to the next larger size through the waist and hips. (See the maternity hack tutorial on Hey June for more details.)
- Because of the negative ease across the stomach, you will need a material with excellent stretch and recovery for this adjustment. This sample uses a cotton-lycra jersey.
A-Line / Swing Top Maternity Adjustment
This type of adjustment adds both length and width to t-shirt, while maintaining the fit of the t-shirt through the bust and shoulders. To do it, we will trace the original pattern piece while “pivot-and-sliding” it at crucial points to add the necessary fabric.
- Trace around original front and back pattern pieces.
- On back piece, slide pattern piece down to add length, then pivot out from center back toward side seams 3/4 inches. Trace bottom hem and side seams.(red dashed line) Draw smooth curves along new hemline from center back to side seam. Then, smooth out curve of side seam at waist if too extreme.
- On front piece, pivot pattern piece at bottom of armhole opening to bring out side seam 5 inches. Trace along side seam and match in length the side seam of the new back pattern piece. (red dashed line)
- Return front pattern to original position. Then, slide original pattern straight down 2 – 4 inches to add length to center front. Trace bottom of front pattern. (purple dashed lines)
- Smooth out curve from new center front hem up to new side seams.
- This type of adjustment adds a lot of volume to the shirt, which can be overwhelming or tent-like in a fabric that doesn’t have a lot of drape. (This sample is sewn in cotton-lycra.) You can add more shape to this style by adding ruching, a tie, or belt horizontally under the bust or ruching vertically along the side seam (RTW example).
- I would love to see this adjustment used with a rayon jersey. It would make for a lovely swingy top.
Gathered Babydoll Maternity Adjustment
This type of adjustment adds stomach fabric by adding an empire waist “skirt” to lay over the bump. It can be made any length from shirt, to tunic, to dress.
- Cut off the bottom of the front and back pattern pieces below the bust. The goal is to attach the skirt at roughly the bottom of the rib cage. Optionally, this cut can curve up about 1 inch at the center front from the side seam.
- To draft the back “skirt”, It is a rectangle that is 150% wider than the width of the back bodice, and long enough to achieve the desired overall length (whether it be top, tunic, or dress). (The skirt pieces are cut on the fold just like the bodice.)
- To draft the front skirt, the width of the skirt is 150% wider than the width of the front bodice. The length of the skirt at the side seams is the same as the length of the back skirt. The length of the center front is 3-4 inches longer than the side seam length. The top of the skirt is gently curved from the side seam to the center front.
- Gathers are used when attaching the skirts to the shirt bodice.
- Again, this adjustment adds a lot of volume, and I would like to see this made up in a drapey rayon.
- You can sew elastic to the waist seam to snug the shirt close to the body, or to support a less-stable knit.
With the mastery of these adjustments, I gained a lot of flexibility in styling my maternity wardrobe and I hope this tutorial helps you too!