G cup maternity bras need to address a specific challenge: a bust that's already substantial becoming heavier and more sensitive through pregnancy, and then fluctuating significantly through each breastfeeding session. The cup needs to be engineered for G cup — wide enough at the base, tall enough to contain the full breast — while also adapting to the size variation that comes with nursing. Standard maternity bras that extend to G cup in name often don't extend the cup engineering to match.
Flexi-wire vs wirefree at G cup
At G cup specifically, this choice matters more than at smaller cup sizes. A wirefree bra at G cup during active breastfeeding typically provides less lift and containment than at D–F cup — breast weight at G cup is significant, and fabric alone (without a wire to support from below) struggles to maintain shape through a full day. For most G cup women, a well-fitted flexi-wire nursing bra is the better daytime choice, with a wirefree style for sleep and at-home comfort. The Australian Breastfeeding Association notes that a correctly fitted flexi-wire bra — where the wire sits on the ribcage rather than on breast tissue — carries lower risk than a rigid underwire during breastfeeding.
What to buy and when
For G cup, fitting at around 36 weeks gives the most accurate pre-birth size. Expect significant fluctuation in the first 4–6 weeks after birth as milk supply establishes. Having two or three nursing bras in rotation is practical — breasts will require more frequent washing than regular lingerie. Browse the full maternity and nursing bra range for all styles. Key brands: Hotmilk (D–J cup) and Cake Lingerie.
