The Ministry of Health wants women taking the oral contraceptive pill Estelle 35/35ED to visit their local doctor or nurse after studies showed women taking them have an increased risk of blood clots.
"Our advice to women taking these pills is to visit their health practitioner before they start their next pack of pills or pick up their next prescription. Women need to discuss the risks and benefits of the pill with their health practitioner before making any decision to stop or change their preferred method of contraception."
For every 100,000 women aged 15-44 years who are not taking a hormonal contraceptive, between five and ten will develop a blood clot in one year.
The risk is three to four times higher for women taking a second generation pill and six to eight times higher for third generation pills.