The Effect of 7 Days of Letrozole Pretreatment Combined With Misoprostol on the Placental and Decidual Tissues

Twenty healthy subjects requesting legal surgical abortion up to 63 days gestation will be recruited for this study. They will be randomized to receive either placebo tablets or letrozole 10 mg daily for 7 days before suction evacuation. Suction evacuates which include the placenta and some decidua collected by the procedure in these 20 subjects will be used for the laboratory studies.

Inclusion criteria

• The gestational age should be up to 63 days. An ultrasound assessment would be performed to confirm the gestation.
• The woman is willing and able to participate after the study has been explained
• Age >18 years old

Exclusion criteria

• Criteria for prospective exclusion

Any indication of past or present ill health will be considered a contraindication for recruitment to the study. In particular, subjects should not be recruited if any of the following conditions is present:

• multiple pregnancies
• uterine fibroids
• any significant medical disorder
• intrauterine contraceptive device in situ
• contra-indications to the use of letrozole or misoprostol

• Criteria for exclusion from a secondary analysis

Situation in which subjects who have been formally admitted to the study could be excluded from a secondary analysis include:

• the use of drugs other than those prescribed by the investigator for the treatment of possible therapy-related side-effects especially drugs with prostaglandin synthetase inhibitory activity such as salicylates, indomethacin or mefenamic acid
• any violation of the study protocol
• essential data missing from the subject's records making it impossible to judge the treatment outcome