THE PREVALENCE OF NONVIABLE PREGNANCY AT 10-13 WEEKS OF GESTATION

In an ultrasound screening study at 10-13 weeks of gestation involving 17 870 women, the prevalence of early pregnancy failure was 2.8% (501 cases), including 313 (62.5%) missed abortions and 188 (37.5%) anemb? yonic pregnancies. Lower gestation and higher maternal age were associ ated with a higher prevalence (chi(2) = 143.5; p < 0.001 and chi(2) = 53.3; p < 0.0001, respectively). The prevalence was higher in women wi th a history of vaginal bleeding (chi(2) = 141.5; p < 0.0001), but the re was no significant association with previous pregnancy losses (chi( 2) = 2.8), parity (chi(2) = 0.6) or cigarette smoking (chi(2) = 0.0). Recent evidence suggests that the most effective method of screening f or chromosomal abnormalities is measurement of fetal nuchal translucen cy thickness at 10-13 weeks, and therefore ultrasound examination at t his gestation is likely to become universally available. As shown in t his study, art additional advantage of such a scan is the diagnosis of early pregnancy failure, which will be found in about 3% of patients examined. Elective evacuation of retained products of conception is li kely to be more cost effective and potentially safer than emergency su rgery in a patient presenting during miscarriage.