G. Connors

Evaluation of the twin peak or lambda sign in determining chorionicity in multiple pregnancy.

Objective To assess prospectively the diagnostic capabilities of ultrasound assessment, using the twin peak or lambda sign, in determining chorionicity in multiple pregnancy. Methods Fifty-five cases of multiple pregnancy were assessed. Real-time ultrasound scans of the origin of the inter-twin membrane for the presence or absence of the twin peak/lambda sign were performed and permanent images recorded. Chorionicity was determined by placental pathologic analysis. Results Presence or absence of the twin peak/lambda sign as determined by real-time ultrasound correctly predicted chorionicity in 34 of 36 dichorionic and seven of eight monochorionic twin pregnancies: sensitivity for dichorionicity 94%, specificity 88%, positive predictive value 97%, and negative predictive value 78%. Real-time assessment was superior to analysis of permanent films. Conclusion Ultrasound assessment of chorionicity using the twin peak/lambda sign has high sensitivity and specificity, but accuracy may not be sufficient to guide clinical management in all cases.

Preinduction cervical ripening: A comparison of intracervical prostaglandin E2 gel versus the Foley catheter

OBJECTIVE Both prostaglandin E2 gel and an intracervical balloon catheter have been shown to be effective for cervical ripening. The purpose of this study is to compare the efficacy of intracervical prostaglandin E2 gel with an intracervical Foley catheter for preinduction cervical ripening. STUDY DESIGN A randomized, prospective study was conducted in the Maternity Care Center at the Foothills Hospital at Calgary, Alberta, Canada. Patients with a Bishop score < or = 4 and meeting inclusion and exclusion criteria were included. Thirty patients were randomized to receive prostaglandin E2 gel and 36 to receive an intracervical Foley catheter on the evening before induction. Induction then proceeded the following morning by the preferred method of the attending physician. RESULTS The groups were comparable with respect to maternal age, parity, gestational age, reason for induction, and initial Bishop scores. Both groups had a significant change in Bishop score (4.1 +/- 0.4 and 4.8 +/- 0.5, respectively, p < 0.001); however, there was no significant difference between the groups. There was no significant difference in side effect profile, intrapartum complications, or delivery mode. Six cesarean sections (17.6%) were performed in the Foley group and seven (25%) in the prostaglandin E2 gel group (not significant). The induction-to-delivery interval was 16.0 +/- 1.7 hours in the Foley group and 21.5 +/- 3.2 hours in the prostaglandin E2 gel group (p = 0.014). Apgar scores, cord gases, and neonatal birth weight showed no difference between the groups. CONCLUSION This study has shown that for preinduction cervical ripening there is no difference in efficacy between intracervical prostaglandin E2 gel or an intracervical Foley catheter.

First‐trimester Down syndrome screening using additional serum markers with and without nuchal translucency and cell‐free DNA

This study aimed to evaluate serum‐only four‐marker first trimester (1T‐Quad) Down syndrome screening, alone or contingently to select 10–20% with highest risk for nuchal translucency (NT) or cell‐free (cf)DNA.

The predictive value of 18 and 22 week uterine artery Doppler in patients with low first trimester maternal serum PAPP-A †

To determine if the addition of uterine artery (UA) Doppler pulsatility index (PI) at 18 and 22 weeks of gestation improves the predictive accuracy of low first trimester pregnancy associated plasma protein A (PAPP‐A) in the detection of adverse obstetrical outcomes.

OC31: Women's satisfaction with the OSCAR (One‐Stop Clinic Assessment of Risk) model of first‐trimester combined screening

Objectives: This study evaluated women’s satisfaction with the OSCAR (One-Stop Clinic Assessment of Risk) first-trimester combined screening (FTS) model introduced in Calgary, Canada in March 2006. Methods: The FTS OSCAR model provides pretest counseling, phlebotomy, blood assay for fβ-hCG, PAPP-A (Delfia TM Xpress), nuchal translucency (NT) scan, the FTS risk calculation (Astraia) and post-test counseling during a 90-min appointment. A satisfaction survey was developed to measure expectations and satisfaction with these various components of service. Additional information collected included the women’s demographics, their recall of their screen result (positive or negative) and whether they felt reassured with testing. Between 13 March 2006–2007, all women referred for the 11–13 + 6 week FTS who agreed to complete the survey were included. Results: Response rate was 75% (3763/5013). Overall, 98.1% of the women were either very satisfied or satisfied and 95.6% felt their expectations were met. These results were independent of maternal age, parity and education. Most women were reassured by testing regardless of results (99.3% and 82.1% of the screen-negative and screen-positive (≥1/300 women, respectively). Most (93%) stated that screening early in pregnancy and receiving test results at the same visit (95.6%) was very important. Conclusions: The FTS OSCAR model meets women’s expectations and is associated with a high degree of satisfaction in terms of timing of screening and rapid availability of results. A high proportion of women were reassured by their results regardless of whether they were screen negative or positive. There was also a relatively low uptake of prenatal diagnosis among the screen-positive women (49%). This may imply that women favor the personal risk assessment and benefit from the 1-1 post-counseling of the OSCAR model. Further research is under way to address these questions.

OP25.01: First trimester combined screening: prospective evaluation of performance in an OSCAR setting

Objectives: The study was performed to assess whether hemodynamic effects on the fetus occur in late-pregnancy mice when ultrasound contrast agent (UCA) (SonoVue TM ) is used for clinical applications in obstetrical ultrasonography. Methods: Sixty late-pregnancy mice (Wister mice, median weight, 300 (range, 260–330) g; median gestational age, 19 (range, 16–21) days) were selected and divided into three experimental groups – Group A, the control group, were injected with physiologic saline solution, Group B were injected with a diagnostic dose of UCA − 0.06 mg/kg body weight – and Group C were injected with a high dose of UCA − 12 mg/kg. From each group a random selection of one mouse was made and it was examined by ACUSON Sequoia 512 with contrast pulse sequencing (CPS) technology. Maternal and fetal heart rate, pulsatility index (PI), resistance index (RI), and systolic: diastolic ratios (S/D) were measured in the fetal middle cerebral artery, umbilical artery, and uterine artery before and after administration of UCA or physiologic saline solution. Results: There were no significant differences in maternal and fetal heart rate, PI, RI, and S/D ratios in the fetal middle cerebral artery, umbilical artery and uterine artery between the different dosage groups of UCA or physiologic saline solution (ANOVA, P > 0.05). A significant decrease in the maternal and fetal heart rate, measured in the uterine artery and in the fetal middle cerebral artery, before and after injection of UCA or physiologic saline solution was found (t-test, P 0.05). Conclusions: The SonoVue TM UCA did not produce any harmful fetal or placental effects in late pregnancy and was shown to be safe in this study. The decreases in maternal and fetal heart rates was probably caused by the stress of the procedure.

P01.22: Nuchal translucency screening in the detection of Down syndrome

Methods: Between 3/2002 and 2/2006, 712 consecutive patients presented for routine prenatal care in a private clinic at approximately 11 to 14 weeks gestation. A sonologist, who is certified for NT measurement by the Fetal Medicine Foundation, performed all the first-trimester scans. Given the un-established reliability and the low acceptance of first-trimester biochemical marker testing in Lebanon, an NT ≥ 2.5 mm was considered a positive screening result. Results: All patients accepted NT screening and outcomes are available on 557 (78%). Missed abortions occurred in 6, fetal death in utero beyond the first trimester occurred in 7, 13 patients were lost to follow up and 129 patients are still undelivered. NT ≥ 2.5 mm occurred in 18 (3.2%) cases. Our screened population had 3 fetuses with trisomy 21 and one fetus with trisomy 18. An NT ≥ 2.5 mm detected the trisomy 18 fetus and 2 of 3 trisomy 21 fetuses. The trisomy 21 fetus that was missed on NT screening was detected in the second trimester because of duodenal atresia on ultrasound. The resulting sensitivity in our population is 75% with a false positive rate of 13/551 (2.4%). In addition, 2 cases of cystic hygromas were detected. Conclusions: To date, this represents the first and largest study of NT screening in Lebanon. Our results suggest that first-trimester screening using NT is feasible and highly acceptable in Lebanon and provided a sensitivity of 75% with a false positive rate of less than 5%. These findings are comparable to reports from other centers.