Women's World Boxing Championship
Venue: Garfield Sobers Stadium, Bridgetown, Barbados Dates: 9-18 September
Coulson had hoped to win a medal in Barbados
English pair Sharon Holford and Amanda Coulson made a disappointing exit in the preliminary stages of the Women's World Boxing Championship in Barbados.
Lightweight Coulson, who is part of Great Britain's podium squad, was beaten 9-6 by Asian champion Mauzuna Choreva from Tajikistan.
Bantamweight Holford lost a narrow contest 11-10 to Venezuelan Flores Leiryn on Thursday in Bridgetown.
Chantelle Cameron, Nicola Adams and Savannah Marshall are yet to box.
Light-welterweight Cameron takes on Lulia Navscioiu on Friday in the preliminary round while flyweight Adams faces Norway's Marielle Hansen in the last 32 on Sunday.
And welterweight Marshall meets Poland's Justyna Sroczynska in the last 16 on Monday.
There was positive news for Welsh home nation boxer Lynsey Holdaway (48kg) who comfortably beat Jacqueline Park of Canada 10-2 to progress.