Probability of early pregnancy loss in women with vaginal bleeding and a singleton live fetus at ultrasound scan.

Bleeding is a common feature of early pregnancy affecting about one-fifth of pregnant women in the first trimester. The chance of miscarriage after bleeding and a live fetus at scan has not previously been defined precisely. The purpose of this study was to evaluate the outcome of early pregnancies with a viable singleton fetus that had been complicated by bleeding. A prospective study was performed on 370 women with a singleton live fetus who had presented to the early pregnancy assessment clinic (EPAC) with vaginal bleeding. Women were grouped into light, moderate and heavy loss according to the self-assessed degree of vaginal bleeding. The women were also categorised according to the presence or absence of an intrauterine haematoma. The overall spontaneous miscarriage rate in the study was 11.1%; almost 90% of pregnancies continued to viability. Women with moderate or heavy bleeding had more than twice the rate of miscarriage compared with those with light bleeding. A total of 14% of the women had an intrauterine haematoma and those women were 2.6 times more likely to miscarry than those without (23% vs 9%). This relationship appeared to hold true even after controlling for blood loss. The data presented can be used to guide women with a live fetus about the chance of miscarriage after an episode of vaginal bleeding. We propose that a large multi-centre study should be undertaken to define precisely the risk miscarriage for each gestational week according to a range of clinical and ultrasound characteristics.