Outcome of assisted reproduction treatment in patients with endometrial thickness less than 7 mm

Endometrial thickness is one of the parameters contributing to the outcome of assisted reproduction treatment. The aim of the current study was to investigate the pregnancy rate and the outcome when the endometrial thickness was <7 mm during a treatment cycle. Treatments conducted between January 2000 and December 2004 at the German Hospital in Istanbul were reviewed retrospectively. A total of 175 embryo transfer cycles with an endometrial thickness of <7 mm on the day of oocyte retrieval were assessed. The 175 oocyte retrieval-embryo transfer cycles resulted in 53 pregnancies (30%), of which 11% were biochemical pregnancies, 26% were miscarriages and 58% were delivered. The clinical pregnancy rate was 26%, miscarriage rate was 31% and live birth rate was 17%. However, the results were quite good when the patient age was <35 years or the number of oocytes retrieved was over five or the number of available embryos to transfer was three or more. In conclusion, when the endometrial thickness is <7 mm during an treatment cycle, the couple should be informed about the chance of pregnancy and the outcome. In a young normoresponder woman with at least three embryos available for transfer, transfer could be carried out, otherwise embryo freezing should be recommended.