After the first trimester, it may become necessary to scale or modify certain movements during CrossFit workouts.  Scaling usually involves a reduction of weight; for example, using a resistance band to assist pull-ups and dips, or using lighter weights (even a training bar or dowel) for Olympic and power lifts.  With pregnancy, however, further modifications may be required in order to accommodate a growing belly, a shifting centre of gravity, an increase in body weight and slackening joints.  The following are some suggestions for modifications that address the specific needs of the pregnant body.  Videos and descriptions for many of these exercises can be found on the CrossFit.com website, and I will try to post some photos later this week.  The list is not exhaustive by any means, but will provide a good starting point for some of the most commonly-encountered movements.

Deadlifts
sumo (wide) stance with regular grip
“suitcase” deadlifts (weights on either side of the body, like picking up heavy suitcases)

Cleans and snatches
use dumbells or kettlebells to keep weight close to the body and eliminate awkward manoeuvring of a bar around the belly

Split jerks
push jerks (balance and ankle joint stability are less critical with this movement than with the split jerk)
push press (when ballistic movements become uncomfortable)

Front, back and overhead squats
reduce range of motion if knee/hip joints feel unstable
air squats (no weights)

Thrusters
push presses
air thrusters (no weights)

Sit-ups
knees to elbows
hanging knee raises when belly becomes to big for knees to elbows
front and side planks
hollow rocks

Push-ups
use yoga blocks, bumper plates or paralletes under hands to raise body higher and provide room for the belly
push-ups on a plyo box or bench
push-ups against the wall

Pull-ups
jumping pull-ups
ring rows (or TRX rows)
using a shoulder-height Olympic bar on a rack, “hang” from it with feet supported on the ground, and pull up

Ring or bar dips
triceps dips on a bench or box, with feet supported on the floor

Burpees
air squat plus box push-up

Handstand push-ups
seated dumbell shoulder press

Box jumps
step-up

GHD hip/back extensions
good mornings

Double-unders
single skips (3:1 ratio)

Wall-balls
reduce range of motion on the squat to accommodate belly

Running
rowing