Management of threatened miscarriage and recurrent miscarriage: guidance on use of progesterone
The Progesterone Pathway ensures that women who have had at least one previous miscarriage and present with early pregnancy bleeding are offered vaginal micronised progesterone, where it is clinically indicated, and provides guidance on asymptomatic women with four or more previous miscarriages.
Background
For the purposes of this guideline, we refer to early pregnancy bleeding under 12 weeks’ gestation as threatened miscarriage. Threatened miscarriage is defined as an episode of vaginal bleeding in early pregnancy, where the cervical os is closed and the pregnancy is normally sited within the uterus and remains potentially viable. It is one of the most common reasons women attend early pregnancy care. In a large study following up couples trying to conceive who became pregnant (n=4539), 27% of women experienced early pregnancy bleeding. In that cohort more than 85% of women were under 34 years of age and the miscarriage rate was 12%. While the incidence of early pregnancy bleeding and miscarriage in more representative older populations is higher than this, it is still true that most women with early pregnancy bleeding will have a continuing pregnancy. Around 60% of women with vaginal bleeding in the first trimester of pregnancy will have a viable pregnancy.
It is important to remember that vaginal bleeding in pregnancy can be a sign of other pathology such as ectopic pregnancy, molar pregnancy, cervical ectopy or, rarely, cervical malignancy. Early pregnancy unit protocols are designed to ensure that other pathology is not missed. That means that women presenting at less than 12 weeks’ gestation with vaginal bleeding should be triaged by staff experienced in early pregnancy care, where possible, to determine the most appropriate management within 24 hours of reporting vaginal bleeding. Assessment usually involves detailed history, ultrasonography +/- speculum examination.