An undergarment (100; 102), comprising: a fabric body having a waist opening and a pair of leg openings (108; 304) defining a crotch region (110; 302) therebetween; and a multilayer leak-proof pad stitched to an interior surface of the fabric body and extending over at least the crotch region, the multilayer leak-proof pad comprising a moisture-impermeable layer in contact with the fabric body; a moisture-absorbent layer thereover; a moisture-wicking layer over the moisture-absorbent layer; and an anti-microbial layer over the moisture-wicking layer; wherein the multilayer leak-proof pad extends over the crotch region and includes pairs of opposed curving peripheral edges, a first pair of edges extending along the leg openings proximate to the crotch region and a second pair of edges being located beyond the crotch region and flaring outwardly; wherein the moisture-impermeable layer is disposed only in the crotch region, and wherein the moisture-absorbent layer, the moisture-wicking layer, and the anti-microbial layer extend as a unitary panel beyond the moisture-impermeable layer up a back panel of the undergarment to a waistband around the waist opening, at least a rear segment of the unitary panel having opposed peripheral edges tapering toward the waistband. a fabric body having a waist opening and a pair of leg openings (108; 304) defining a crotch region (110; 302) therebetween; and a multilayer leak-proof pad stitched to an interior surface of the fabric body and extending over at least the crotch region, the multilayer leak-proof pad comprising a moisture-impermeable layer in contact with the fabric body; a moisture-absorbent layer thereover; a moisture-wicking layer over the moisture-absorbent layer; and an anti-microbial layer over the moisture-wicking layer; wherein the multilayer leak-proof pad extends over the crotch region and includes pairs of opposed curving peripheral edges, a first pair of edges extending along the leg openings proximate to the crotch region and a second pair of edges being located beyond the crotch region and flaring outwardly; wherein the moisture-impermeable layer is disposed only in the crotch region, and wherein the moisture-absorbent layer, the moisture-wicking layer, and the anti-microbial layer extend as a unitary panel beyond the moisture-impermeable layer up a back panel of the undergarment to a waistband around the waist opening, at least a rear segment of the unitary panel having opposed peripheral edges tapering toward the waistband. wherein the multilayer leak-proof pad extends over the crotch region and includes pairs of opposed curving peripheral edges, a first pair of edges extending along the leg openings proximate to the crotch region and a second pair of edges being located beyond the crotch region and flaring outwardly; wherein the moisture-impermeable layer is disposed only in the crotch region, and wherein the moisture-absorbent layer, the moisture-wicking layer, and the anti-microbial layer extend as a unitary panel beyond the moisture-impermeable layer up a back panel of the undergarment to a waistband around the waist opening, at least a rear segment of the unitary panel having opposed peripheral edges tapering toward the waistband.