Clomiphene citrate utilization in the Netherlands 1998-2007

Infertility is a growing problem in western societies. Few studies have examined the drug utilization of common treatments for infertility. Clomiphene citrate (CC) is the first-line treatment for normogonadotropic women with absent or irregular ovulation. We examined CC use among women at reproductive age in the northern Netherlands.

Drug dispensing data of CC between 1998 and 2007 were retrieved from the IADB.nl database. Two-year prevalences of CC use per 1000 women covered by the database were calculated and stratified by 5-year age group. The duration of CC use was analyzed using Kaplan-Meier survival analysis.

From the IADB.nl database, a total of 1854 women aged 20-44 years initiated ovulation induction treatment with CC only in the northern Netherlands during 1998 and 2007. The 2-year prevalence of CC use increased from 6.66 per 1000 women during 1998-1999 to 7.24 per 1000 during 2002-2003, followed by a decrease to 4.82 per 1000 in 2006-2007 (P < 0.05). Median duration of CC use was four cycles for women <30 years of age, three cycles for women aged 30-39 and two cycles for women aged above 40.

There is no increase of CC use during 1998-2007, and indeed a decrease of CC use during recent years, among women at reproductive age in northern Netherlands.