Generally, in the sixth month of gestation, the pregnancy is obvious to the majority of people. WebMD points out that most women in the sixth month, weeks 21 to 25, have a noticeable weight gain.
WebMD indicates that 12 to 15 pounds are generally gained by week 23, and approximately a pound per week is gained for the remainder of the month. The abdomen begins to extend above the navel. Most pregnant women in their sixth month also have some swelling of the feet and ankles. In week 25, women may also notice their abdomen beginning to swell from side-to-side.