Defining safe criteria to diagnose miscarriage: prospective observational multicentre study.

OBJECTIVES: To validate recent guidance changes by establishing the performance of cut-off values for embryo crown-rump length and mean gestational sac diameter to diagnose miscarriage with high levels of certainty. Secondary aims were to examine the influence of gestational age on interpretation of mean gestational sac diameter and crown-rump length values, determine the optimal intervals between scans and findings on repeat scans that definitively diagnose pregnancy failure.) DESIGN: Prospective multicentre observational trial. SETTING: Seven hospital based early pregnancy assessment units in the United Kingdom. PARTICIPANTS: 2845 women with intrauterine pregnancies of unknown viability included if transvaginal ultrasonography showed an intrauterine pregnancy of uncertain viability. In three hospitals this was initially defined as an empty gestational sac <20 mm mean diameter with or without a visible yolk sac but no embryo, or an embryo with crown-rump length <6 mm with no heartbeat. Following amended guidance in December 2011 this definition changed to a gestational sac size <25 mm or embryo crown-rump length <7 mm. At one unit the definition was extended throughout to include a mean gestational sac diameter <30 mm or embryo crown-rump length <8 mm. MAIN OUTCOME MEASURES: Mean gestational sac diameter, crown-rump length, and presence or absence of embryo heart activity at initial and repeat transvaginal ultrasonography around 7-14 days later. The final outcome was pregnancy viability at 11-14 weeks' gestation. RESULTS: The following indicated a miscarriage at initial scan: mean gestational sac diameter ≥ 25 mm with an empty sac (364/364 specificity: 100%, 95% confidence interval 99.0% to 100%), embryo with crown-rump length ≥ 7 mm without visible embryo heart activity (110/110 specificity: 100%, 96.7% to 100%), mean gestational sac diameter ≥ 18 mm for gestational sacs without an embryo presenting after 70 days' gestation (907/907 specificity: 100%, 99.6% to 100%), embryo with crown-rump length ≥ 3 mm without visible heart activity presenting after 70 days' gestation (87/87 specificity: 100%, 95.8% to 100%). The following were indicative of miscarriage at a repeat scan: initial scan and repeat scan after seven days or more showing an embryo without visible heart activity (103/103 specificity: 100%, 96.5% to 100%), pregnancies without an embryo and mean gestational sac diameter <12 mm where the mean diameter has not doubled after 14 days or more (478/478 specificity: 100%, 99.2% to 100%), pregnancies without an embryo and mean gestational sac diameter ≥ 12 mm showing no embryo heartbeat after seven days or more (150/150 specificity: 100%, 97.6% to 100%). CONCLUSIONS: Recently changed cut-off values of gestational sac and embryo size defining miscarriage are appropriate and not too conservative but do not take into account gestational age. Guidance on timing between scans and expected findings on repeat scans are still too liberal. Protocols for miscarriage diagnosis should be reviewed to account for this evidence to avoid misdiagnosis and the risk of terminating viable pregnancies.

Risk factors for obstetric admissions to the intensive care unit in a tertiary hospital: a case-control study.

OBJECTIVE: The objective was to review all obstetric admissions to the intensive care unit (ICU) at the Royal Free Hospital, London, UK, and to identify the risk factors for obstetric admissions to the ICU. METHOD: We carried out a retrospective case-control study. The cases consisted of women admitted to the ICU during pregnancy and up to 42 days postpartum between 1 January 1993 and 31 December 2003. Controls were women who delivered immediately before and after the indexed case. Demographic data, medical and surgical histories, pregnancy, and intrapartum and postpartum data were collected. Statistical analysis was done using SPSS software. RESULTS: Thirty-three obstetric patients were admitted to the ICU, representing 0.11% of all deliveries. The ICU utilization rate was 0.81%. Eighty percent of the admissions were postpartum. The main indications for admission were hypertensive disorders (39.4%), and obstetric haemorrhage (36.4%). There was no difference between cases and controls in, age, parity, smoking and employment status. Compared with controls, women admitted to the ICU were significantly more likely to be black (P<0.05), have a shorter mean duration of pregnancy (36.6 vs. 39.2 weeks; P=0.006), delivered by emergency caesarean section (P<0.001), and have higher mean blood loss at delivery (1,173 vs. 296 ml; P<0.001). The risk factors for obstetric ICU admission were black race (odds ratio [OR] =2.8, 95% confidence interval [CI] 1.05-6.28), emergency caesarean section (OR=14.9, 95% CI 5.38-41.45) and primary postpartum haemorrhage (OR=5.4, 95% CI 1.79-4.35). CONCLUSION: Women of black race, those delivered by emergency caesarean section and those with primary postpartum haemorrhage are more likely to be admitted to the ICU.