In July 1988 she won the 800m and 1500m at the Balkan Games in Ankara, winning 800m in career best time of 1:56.42. On 27 July at Verona Ivan broke the 4-minute mark over 1500m for the first time in career, clocking 3:58.80, improving to 3:56.22 when winning in Zurich on 17 August.
At the 1988 Summer Olympics in Seoul, Korea she won the Silver medal in her first event, the 3000m, and then Gold in the 1500m final held six days later. In the latter event her winning time, 3:53.96, was a new Olympic record.
In 1989 Ivan won the 1500m at the European Indoor Championships in Den Haag, in a time of 4:07.16. Later that year, outdoors, she broke the world record for the mile with a time of 4:15.61. She repeated her 1500m/3000m golden double at the Universiade in Duisburg in August and then the 1500m at the World Cup in Barcelona in September. She then retired from the sport to become a coach.
In 2000, now 36 years old and after ten seasons away from competition, Ivan returned for one more season. She ran the 1500m in several meets on the IAAF Grand Prix circuit, with her season's best time being 4:04.66, at the Monte Carlo Herculis-Zepter meet, on 18 August 2000.
She also competed in the IAAF World Cross Country Championships four times (1984-1987). In the 1985 championship race, she was part of the Romanian team that earned the team bronze medal (Ivan finished 34th). Her best individual performance was a 9th place finish at the 1987 championship race in Warsaw.
Since 2002, she has been a member of the Faculty of Physical Education and Sport at Spiru Haret University in Bucharest.