NORPLANT was introduced into the Chinese family planning programmes in
1984 by the Population Council. After a pilot study of 1200 cases in
four centres in China, the study was expanded to 12 centres with 10,71
8 cases of NORPLANT and 1208 cases of NORPLANT-2 followed up for more
than 6 years. The 5 years net cumulative pregnancy rates were 0.5-1.2
and the net cumulative continuation rates were around 65-72 per 100 us
ers. There were significant differences in pregnancy rates between dif
ferent groups of body weight and age, i.e. the pregnancy rates were hi
gher in groups with body weight over 70 kg and those aged below 25 yea
rs. The age, body weight and dependence on contraceptive effectiveness
of NORPLANT should be taken into account in the selection of users. N
ationwide large-scale studies in provincial and country rural areas an
d postmarketing surveillance are being carried out. Changes in ovarian
function and endometrium have been studied. Levonorgestrel IUD (LNg-I
UD) was introduced into China in 1985. Comparative clinical studies on
NORPLANT and LNg-IUD, pharmacokinetic and pharmacodynamic studies and
endometrial studies of LNg-IUD were performed. The higher percentage
(55.1%) of ovarian suppression in Chinese users of LNg-IUD may be attr
ibuted to ethnic differences among Caucasian women in their susceptibi
ity to steroid hormones. Results showed favourable acceptance of both
devices among Chinese women. The studies promoted the incorporation of
new long-acting contraceptive methods into the Chinese family plannin
g programmes.