Background: As genital chlamydia (Chlamydia trachomatis) notifications have increased in Australia, time trends in hospitalisations for ectopic pregnancy and female infertility between 2001 and 2008 in New South Wales (NSW), Australia, and their relationship to trends in chlamydia notifications in women were assessed.
Methods: Annual rates of chlamydia notification, and hospitalisations for female infertility or ectopic pregnancy in women aged 15-44 years in NSW were calculated using routinely collected data. Chlamydia notifications and hospital separations occurring within each year belonging to the same woman were linked using probabilistic linkage of identifiers so that multiple notifications and admissions for one woman in each calendar year were only counted once.
Results: From 2001 to 2008, the annual rate of chlamydia diagnoses in women increased from 157 to 477 per 100000 population (P(trend)<0.001). Over the same period, the annual hospitalisation rate for women with an ectopic pregnancy decreased from 14.3 to 12.6 per 1000 births (P(trend)<0.001). This decrease was mostly in women aged 25-44 years, with no appreciable fall in women aged 15-24 years (P(trend)=0.8). Meanwhile, the hospitalisation rate for women with infertility of female origin did not follow a consistent trend: between 2001 and 2008, it fluctuated between a low of 479 and a high of 554 per 10000 women who were seeking pregnancy.
Conclusions: These trends in ectopic pregnancy and female infertility suggest that the large increase in chlamydia notifications may not reflect hospitalisations for these two proposed chlamydia-related sequelae.