Predicting outcome after emergent cerclage using classification tree analysis.

We sought to develop a predictive model for gestational age at delivery after placement of an emergent cerclage in the second trimester. Data were obtained for women undergoing emergent cerclage in response to documented cervical change on physical examination at a university hospital between 1980 and 2000. Hierarchically optimal classification tree analysis (CTA) was used to predict delivery prior to 24 weeks, between 24 and 27 6/7 weeks, or after 27 6/7 weeks. One hundred sixteen women were available for analysis. Delivery prior to 24 weeks was best predicted by presence of prolapsed membranes and gestational age at cerclage placement; delivery between 24 and 27 6/7 weeks was best predicted by parity alone; delivery of at least 28 weeks was best predicted by cervical dilation and length, presence of prolapsed membranes, and parity. When choosing a single model to predict delivery at the three different gestational age periods, the last model yielded the most accurate results. CTA can be used to construct a predictive model for outcome after emergent cerclage that may be informative for both patients and physicians.

Factors associated with success of emergent second-trimester cerclage.

OBJECTIVE: To assess the factors associated with delivery greater than or equal to 28 weeks' gestation after placement of an emergent cerclage in women with singleton gestations. METHODS: All women who underwent emergent cerclage, defined as any cerclage placed between 16 and 24 6/7 weeks' gestation in response to documented cervical change on physical examination, at Northwestern Memorial Hospital from 1980 to 2000 were identified. Univariable and multivariable analyses were used to determine the factors most associated with achieving at least 28 weeks' gestation. RESULTS: One hundred sixteen women were eligible for analysis. Maternal age, race, and operative variables such as suture type and use of antibiotics were not associated with differences in the frequency of delivery at or after 28 weeks. Cerclage placement at or after 22 weeks' gestation increased the likelihood of reaching 28 weeks, whereas several cervical examination findings (dilatation greater than 3 cm, cervical length less than 0.5 cm, and membranes prolapsing beyond the external cervical os) as well as need for placement in a nullipara significantly reduced the likelihood of reaching 28 weeks. In multivariable analysis, nulliparity (odds ratio 0.31, 95% confidence interval 0.1, 0.8) and membranes prolapsing beyond the external cervical os (odds ratio 0.24, 95% confidence interval 0.1, 0.4) continued to be associated with delivery before 28 weeks, whereas cerclage placement at or after 22 weeks (odds ratio 3.2, 95% confidence interval 1.2, 8.6) increased the chance of achieving at least 28 weeks' gestation. CONCLUSION: Nulliparity, the presence of membranes prolapsing beyond the external cervical os, and gestational age less than 22 weeks at cerclage placement are associated with decreased chance of delivery at or after 28 weeks after emergent cerclage; these factors may be used to help counsel patients considering the procedure.

The spinal needle test effectively measures abdominal wall thickness before cannula placement at laparoscopy.

STUDY OBJECTIVE: To demonstrate the usefulness of the spinal needle test at laparoscopy to correlate abdominal wall thickness at initial entry sites with body mass index (BMI). DESIGN: Prospective cohort study (Canadian Task Force classification). SETTING: University-affiliated hospital. PATIENTS: One hundred thirty-eight women. INTERVENTION: Diagnostic laparoscopy. MEASUREMENTS AND MAIN RESULTS: After CO(2) insufflation, the spinal needle test was performed by inserting a spinal needle attached to a partially filled syringe and advancing it perpendicular to the skin until the gas pocket was reached. To improve precision, the distance was measured 3 times at two sites, the umbilicus and Palmer's point (left upper quadrant). Patients' mean BMI was 25.8 kg/m(2) (range 17.2-60.0 kg/m(2)), with 24 (17%) considered clinically obese (BMI > or =30 kg/m(2)). A significant correlation was noted between BMI and abdominal wall thickness at the umbilicus (R = 0.69) and left upper quadrant (R = 0.81). Excellent correlation was also noted between body weight and thickness at the two points (R = 0.72 and R = 0.78, respectively). The mean thickness at the umbilicus differed significantly between obese (3.0 +/- 1.2 cm) and nonobese women (1.7 +/- 0.7 cm, p <0.001); as did mean thickness at the left upper quadrant (4.4 +/- 1.0 vs 2.0 +/- 0.7 cm, p <0.001). CONCLUSION: Thickness of the abdominal wall at umbilical and left upper quadrant entry sites correlates well with weight and BMI. Even among obese women, the distance to the pocket of gas after insufflation at either entry site is remarkably small.