Butterick 5337 Vintage sewing pattern, dated 1991.

Misses'/Misses' Petite Very Easy Maternity Jumper & Jumpsuit:

Pullover jumper, lower calf or pull-on jumpsuit, above or below ankle, has loose-fitting bodice with raised waist, shoulder and side Velcro@ closing, ties and pockets. Purchased top. A: flared skirt. B, C: leg bands. 

Size   8 10 12:

Bust  31 1/2 - 32 1/2 - 34 inches / 80 - 83 - 87 cm

Waist 24 - 25 - 26 1/2 inches / 61 - 64 - 67 cm

Hip    33 1/2 - 34 1/2 - 36 inches / 85 - 88 - 92 cm

Pattern is partly cut to size 12 and checked complete, in good condition. Envelope is in good vintage condition with some tape around the opening.

More maternity patterns here:

https://allthepreciousthings.com.au/collections/maternity