Elena Ciriello

Risks of induction of labour in women with a uterine scar from previous low transverse caesarean section

Objective  Recent studies have shown that among women with uterine scars from previous caesarean section of any type, induction of labour is associated with increased risk of uterine rupture compared with spontaneous labour. We have assessed the risk of uterine rupture in a cohort of women with a previous low transverse caesarean section in whom induction and management of labour were performed according to a strict protocol.

Comparative analysis of cesarean delivery rates over a 10-year period in a single Institution using 10-class classification.

Objective: To evaluate the variables associated with changes in cesarean delivery (CD) rates in a University Hospital with standardized and unchanged protocols of care. Methods: Retrospective analysis of consecutive deliveries between two triennia 10 years apart. The Robson classification of CD was used, and the analysis focused on factors affecting Robson’s classes 1 and 2 combined (term singleton cephalic nulliparae) and class 5 (previous CD). Results: A total of 8237 deliveries occurred in the 1st period, and 8420 in the 2nd. CD increased from 12.5 to 18% (p < 0.001). Robson’s classes 1 and 2 combined contributed more than other classes to CD rates (32 vs 36%; p < 0.001). At multivariate analysis, BMI (Odds ratio [OR]: 1.08; 95% CI: 1.06–1.1) and maternal age (OR: 1.06; 95% CI: 1.05–1.08) were independently related to CD. In Robson class 5, the rate of CD increased from 34 to 46%, p < 0.001, mostly due to an increase in elective CD (39 vs 67.5%; p < 0.001). At multivariate analysis, BMI (OR: 1.06 95% CI: 1.02–1.1) and more than one previous CD (OR: 18.7; 95% CI: 9.6–36.4) were independently related to CD. Conclusions: BMI and maternal age are independent factors associated to the increasing rate of CD in nulliparae with spontaneous or induced labor at term. In women with previous CD, BMI and more than one previous CD are factors associated with the increasing rate of CD.

Role of FISH on Uncultured Amniocytes for the Diagnosis of Aneuploidies in the Presence of Fetal Anomalies

Objective: To assess the accuracy of fluorescent in situ hybridization (FISH) on amniocytes in fetuses affected by structural malformations suggestive of chromosomal anomalies. Methods: FISH of uncultured amniotic fluid cells and conventional cytogenetic analysis were performed on 48 pregnancies with ultrasonographic (US) evidence of fetal anomalies. The AneuVysion® assay (Vysis) with specific probes for chromosomes 13, 18, 21, X and Y, was used. Amniotic fluid samples were obtained between the 14th and 34th weeks of gestation. Results: In cases with a single abnormal US finding (n = 15), 5 aneuploidies were detected (1 case of trisomy 13 and 4 of trisomy 21). In the group with two or more malformations (n = 33) there were 15 aneuploidies (9 cases of trisomy 18, 2 of trisomy 21, 2 monosomy X, 1 trisomy 13, and 1 triploidy). In this group, conventional cytogenetic analysis revealed two additional chromosomal anomalies not detectable by FISH (1 trisomy 16 mosaic, and a terminal deletion 4p). No sex aneuploidies were observed. Conclusions: The lack of false-positive diagnosis in the FISH analysis in our sample prompts us to consider interphase FISH as a useful tool in pregnancies at high risk for chromosomal aneuploidies. When FISH analysis is normal, the overall risk of chromosomal abnormalities is significantly reduced. However, the finding of two chromosomal anomalies undetectable by AneuVysion® assay confirms the need for conventional chromosome analysis to complement FISH results. Moreover, the results collected here, in agreement with those already reported in the literature, indicate that FISH analysis on uncultured amniocytes can play an important role in counselling and decision-making, especially in cases at risk for aneuploidies, such as those with structural abnormalities at US.

Induction of labor: comparison of a cohort with uterine scar from previous cesarean section vs. a cohort with intact uterus.

Objective. To compare the risk of uterine rupture between a cohort of women with previous low-transverse cesarean section (CS) and a cohort with intact uterus. Methods. All women with a singleton pregnancy and previous low-transverse CS requiring induction of labor from January 1, 1992 to December 30, 2001 (n = 310) were compared with a cohort of women with intact uterus undergoing induction of labor during the same study period (n = 5420). Protocols of induction using prostaglandin E2 gel and oxytocin infusion were consistent within groups, but differed between the previous CS and the intact uterus group. Results. Uterine rupture occurred in 0.3% in the previous CS group vs. 0.03% in the intact uterus group (p = 0.37). Logistic regression analysis showed no significant difference in rate of uterine rupture between the previous CS vs. intact uterus group (p = 0.16) after controlling for maternal age, parity, gestational age at delivery, Bishop score on admission, use of prostaglandin and oxytocin, and birth weight. Our study had adequate power to detect a 0.38% difference in rate of uterine rupture between the two groups (α = 0.05, β = 0.80). Conclusion. Induction of labor is not associated with significantly higher rates of uterine rupture among women with previous low-transverse CS compared with women with intact uterus provided a consistent protocol with strict intervention criteria is adopted.

P01.01: Accuracy of antenatal detection of congenital heart disease: assessment in a large cohort at a single institution

Objective: To assess the accuracy of prenatal ultrasonography (US) for congenital heart defects (CHD) in the entire pregnant population undergoing US examination over a 10-year period. Study design: From 1/1990 to 12/2002, 30746 pregnant women underwent prenatal US examination inclusive of four-chambers view in all cases and ventricular outflow tracts in about 50% of cases. The operators were obstetricians with a different degree of experience in US (2 months–20 years). The prenatal detection rate (DR) of US in the detection of CHD was related to the type of anomaly and indications for the US exam (screening vs other indications/referral). All patients were followed until delivery or pregnancy termination. Clinical or autopsy confirmation of abnormal antenatal finding was obtained in all cases. Neonatal echocardiogram was performed in all babies admitted to NICU, in those with heart murmurs detected within 24 hours of birth, and in those with dysmorphic features. Obstetricians and neonatologists met weekly to discuss cases of cardiac anomaly diagnosed preor post-natally. Statistical analysis included Chi-square. Results: 313 cases of CHD occurred (1%), of which 228 (73%) were detected prenatally. The DR for the different subgroups of cardiac malformation were: 1) isolated septal defects: 44% (48/108); 2) atrio-ventricular canals: 95% (52/55); 3) isolated conotruncal defects: 88% (49/56); 4) malformations affecting the size of ventricles: 97% (55/57); 5) other malformations: 62% (23/37). The DR was 40% in screening scans (low-risk pregnancies) and 82% among referrals (p < 0001). Conclusion: In this largest cohort of prenatal screening for CHD, the DR was 73%. Septal defects contributed heavily to the false-positive results. The indication for the US scan significantly influences the sensitivity of the test.