"The high infant mortality rate was 29 per 1,000 lives and no one had any idea why. There was no systematic analysis or pediatric research," Dr. Dover said.
For her study, Dr. Hardy turned to the "huge number of pregnant women in East Baltimore," Dr. Dover said.
Doctors examining children who remained in the study for seven or eight years checked for "origins of such neurological and sensory disorders as mental retardation, cerebral palsy, and learning disorders," according to the magazine profile.
Pregnant mothers who visited Hopkins once a month for checkups donated blood samples, and at birth umbilical cord samples were taken.
"She had the insight to collect and store away plasma and blood samples," Dr. Dover said.
Even though participants in the study were unpaid and sometimes stopped coming or moved away, Dr. Hardy diligently followed up on them.
"She sent taxis to their doors to ferry them to doctors' appointments and always remembered to send birthday and Christmas cards. 'Thank you for coming,' Hardy and her staff always told the women. 'Without your help there would be no study,' " the magazine reported.
Data collected from the study revealed what drugs were unsafe for pregnant mothers and how damaging rubella and other infectious diseases could be to fetuses.
"She proved that many chronic adult diseases had their origins in the uterus," Dr. Dover said.
Well into the 1980s, Dr. Hardy and her colleagues at Hopkins were still tracking participants from the original study and their children and grandchildren.
Alarmed by the high national rate of teen pregnancies in the late 1970s, Dr. Hardy became director of the Johns Hopkins Adolescent Pregnancy and Pregnancy Prevention Program.
The program targeted two city schools, Dunbar High and Lombard Junior High. Students were exposed to sex education, counseling and birth control.
By the early 1990s, births to school-age mothers in Baltimore were declining.
"It is really good news that, at long last, there may be a break in the slow but steady increase in births to adolescents," Dr. Hardy wrote in an Evening Sun op-ed page piece in 1991. "Moreover, the decrease is marked among the youngest and most vulnerable girls, those from 10 to 15 years old."
Among other of Dr. Hardy's substantial achievements, she was the fifth woman to be given the rank of full professor at the Johns Hopkins Medical School.
Dr. Hardy, who remained an indefatigable researcher, continued publishing in academic journals until recent years.
Officially retired in 1981, Dr. Hardy, who was given professor emeritus status, continued working at Hopkins another 20 years, and reopened her CPP databank in the early 1990s to track the original members and their children of the 1957 CPP study.
She and her husband of 69 years, Dr. Paul H. Hardy, a retired Hopkins microbiologist, lived on their 35-acre farm in Glen Arm, where they raised horses and canned their own jam.
In 2004, they moved to the Glen Meadows retirement community, 11630 Glen Arm Road, where a memorial service will be held at 3 p.m. tomorrow.
Also surviving are a son, David B. Hardy of Northampton, Mass.; a daughter, Janet H. "Jenny" Thayer of Glen Arm; a sister, Christine MacLean of Victoria; and three grandchildren.
