I looked at all designers from Generation 1 to 7 and here are the percentage of male and female designers per Generation.

Generation 1 had 4 designers
3 (75 %) - 1 (25 %)

Generation 2 had 8 designers
5 (62.5 %) - 3 (37.5 %)

Generation 3 had 13 designers
7 (53.85 %) - 6 (46.15 %)

Until this point the female designers have continued to rise, but for some reason, the most women that joined GF for Generation 3 got replaced by men and we got Generation 4 with almost only male designers. DP had only 3 female designers, Hyunjung Lee joined later for Platinum and designed Heat Rotom. So the reason for the bulky/monster designs in Generation 4 were men.

Generation 4 had 14 designers
10 (71.43 %) - 4 (28.57 %)

GF may have realized that they had too many men in the designer staff and hired a lot of female designers and only 3 new male ones for Generation 5.

Generation 5 had 18 designers
10 (55.56 %) - 8 (44.44 %)

Generation 6 had 21 designers
11 (52.38 %) - 10 (47.62 %)

The trend continues to rise and the female designers surpass the male designers for the first time. The Pokémon from Generation 6 were designed by women for the most part, which also speaks for the cute and colorful designs.

Generation 7 had 22 designers
10 (45.45 %) - 12 (54.55 %)

The question now is, how will it be in Generation 8? Will there be more women than men as designers again? Or will there be another crash like Generation 4, where most Pokémon were designed by men? What do you hope for the future?