>>42360594
Here's that comic, and the story:
https://www.fimfiction.net/story/526921/14/short-stories-with-pregnant-ponies/syrupy-sweet

Mrs. Cake yawned. She had long grown used to a baker’s early schedule, but occasionally wished she could sleep in. Well, the feeling was nothing coffee and fresh donuts wouldn’t wash away. She heard bumping around in the kitchen, and Carrot was shaving, so Cup Cake wasn’t surprised to see that Pinkie Pie had beat her to baking the day’s first treats.

Pinkie sat on her rump near the counter, and Cup noticed quite a few more treats missing from the first tray than was normal. That was before she saw the other trays, empty. Pinkie was pouring glaze into her mouth, straight from the bowl; it splattered on her large foal bump.

“You should cut back on the sweets, Pinkie. You don’t want to get gestational diabetes like I did with the twins.”

“But I do, because I want my foal to be super sweet!”

Cup rolled her eyes.