Should tissue from pregnancy termination and uterine evacuation routinely be examined histologically?

To assess the value of routine histological examination of tissue samples collected at termination of pregnancy in the first trimester and emergency surgical uterine evacuation.

The gynaecological department of a teaching hospital.

Prospective study of women attending the gynaecological department in a 12-month period.

All women undergoing a therapeutic first trimester medical or surgical abortion or an emergency surgical evacuation of a failed pregnancy, suspected incomplete spontaneous miscarriage or incomplete induced abortion.

Association of pre-operative clinical diagnosis and the post-operative histological result.

Of 1,576 women studied, the histological report confirmed that products of conception were obtained in 1,465 (93%); in two women (0.13%) molar changes were reported confirming the preoperative diagnosis by ultrasound. Products of conception were not confirmed in the tissue specimens in 0.5% medical terminations, 5% surgical terminations, 10% evacuations following a previous evacuation, 12% evacuations for a failed pregnancy, and 19% evacuations for an incomplete miscarriage. In 87 women (6%), decidua was reported; two of these women had undergone an evacuation for an ultrasound diagnosis of spontaneous miscarriage, but in both a tubal ectopic pregnancy was subsequently diagnosed.

There did not appear to be any obvious benefit from routine histological examination of tissue removed at termination of pregnancy or emergency uterine evacuation. The histological result was sometimes not consistent with the pre-operative diagnosis and may result in unnecessary further investigation and treatment unless due consideration is given to the clinical presentation.