GROWTH OF POSTMENARCHEAL GIRLS FROM 3 ETHNIC-GROUPS

Documentation of normal growth in late adolescence has been limited to a few studies using largely white participants. Annual growth rates o f 668 high school girls who had already achieved menarche were determi ned for stature, sitting height, and knee height measured using the Kn ee Height Measuring Device (KHMD), an instrument with superior reliabi lity. The sample was 61.4% white, 16.8% Puerto Rican, 15.7% African Am erican, and 6.1% girls of other ethnic backgrounds, Median growth rate was 1.5 cm/year for stature, 1.1 cm/year for sitting height, and 2.7 mm/year for knee height in the first full year after menarche, and >80 % of all girls grew in at least one dimension. Growth in stature (grea ter than or equal to 1 cm) continued for 64% of girls 1 full year afte r menarche and for 31% of girls 2 years after menarche, and growth in knee height (greater than or equal to 1 mm) continued in >45% of girls up to 5 completed years past menarche. Whites, African Americans, and Puerto Ricans showed small but significant differences in amounts of postmenarcheal growth in the dimensions measured. African-American gir ls grew less in stature and sitting height than other groups, whereas Puerto Rican girls grew significantly more in sitting height and signi ficantly less in knee height than other ethnic groups. These findings demonstrate that, as documented in other studies of postmenarcheal gro wth, there is substantial growth after menarche in most girls. The mos t sensitive measures indicate that small amounts of growth persist >5 years after menarche, Appreciation of this phenomenon needs to be comm unicated to clinicians who generally assume that growth ceases at/or j ust after menarche. (C) 1996 Wiley-Liss, Inc.