Jacques Jani

P343a: Fetoscopic laser treatment in monochorionic and dichorionic triplets

(MC) has a longer latency compared to singleton or dichorionic (DC) twin pregnancies with AEDF. Methods: All patients with AEDF in the UA were identified by search of the patient databases in 2 fetal medicine centres. After excluding 21 pregnancies due to incomplete data (n = 18), and structural or chromosomal anomalies (n = 3), a total of 53 MC pregnancies were compared with two cohort groups – singleton pregnancies (n = 74) and dichorionic twins (n = 19). Latency was defined as days from diagnosis of AEDF till delivery or intrauterine death. Results: A total of 146 pregnancies with AEDF were analysed, including 25 MC twins with IUGR (17%) and 28 with TTTS (19%). Median latency was 43 days (7–153) in the MC group, 30 days (1–66) in the DC group and 10 days (range 0–68) in the singletons. MC twins had significantly longer latency than the singletons (p = 0.007), but there was no significant difference with the DCDA. After excluding the TTTS group, non-TTTS MC twins had a significantly longer latency than DC twins. The overall median gestational age at onset of AEDF [176 days (range: 108–253)] was significantly earlier in MC twins (median 147 days) than in DC (190 days) or singleton (189.50 days) pregnancies (p < 0.001). Latency was linearly correlated with gestational age at onset of AEDF (R2 = 0.564). Conclusion: The latency of AEDF is longer in MC twins, suggesting a different patho-physiological mechanism then simple downstream resistance.

3446: Left and right lung volumes in fetuses with diaphragmatic hernia

OBJECTIVE To compare the volume of the ipsilateral and contralateral lungs in fetuses with congenital diaphragmatic hernia (CDH). METHODS Left and right lung volumes were measured using three-dimensional (3D) ultrasonography in 42 fetuses with CDH at median 26 (range, 20-32) weeks of gestation. Each value was then expressed as a difference, in standard deviations, from the normal mean for gestation, previously established from the study of 650 normal fetuses at 12-32 weeks (Z-score). The Mann-Whitney U-test was used to determine the significance of the differences between the measurements in fetuses with CDH and normal fetuses and between the ipsilateral and contralateral lungs in fetuses with left- and right-sided CDH. RESULTS There were 34 fetuses with left-sided CDH and eight with right-sided CDH. In CDH both the ipsilateral and contralateral lung volumes were substantially lower than in normal fetuses. In left CDH the left lung volume was 4.03 (median; range, 3.11-4.78) SDs below the normal mean for gestation, and the respective values for the right lung were 3.04 (median; range, 1.78-4.31) SDs (P < 0.001 for both). In right CDH, the left lung volume was 2.91 (median; range, 1.62-4.07) SDs below the normal mean for gestation and the respective values for the right lung were 4.35 (median; range, 3.07-4.99) SDs (P < 0.001 for both). In both left and right diaphragmatic hernia the deficit in the volume of the ipsilateral lung was significantly greater than the deficit in the contralateral lung. CONCLUSIONS In fetuses with CDH both the ipsilateral and contralateral lung volumes are substantially lower than in normal fetuses.

P06.08: TTTS before the limits of fetoscopic surgery

Results: 1037 were referred from January 1999 to May 2004. 189 patients (18.2%) had non-TTTS. Of these, 78 (41.2%) were iOLIGO, 65 (34.4%) iPOLY, and 46 (24.3%) sAFVd. Complete follow-up data was available in 141/189 (74.5%) patients. Progression to TTTS occurred in 37%, 26%, and 3% of iOLIGO, iPOLY and sAFVd groups, respectively (p < 0.001). iOLIGO patients were more likely to progress to IUGR than iPOLY patients (p < 0.04). Altogether, iOLIGO patients were less likely to remain unchanged (6.5%) than iPOLY (47.8%) or sAFVd (54%) (p < 0.001). Spontaneous normalization of AFV occurred in 6.5%, 2.2% and 54% of iOLIGO, iPOLY and sAFVd patients, respectively (p < 0.001). The average time for the development of TTTS in non-TTTS patients was 6.5 days. Conclusion: Monochorionic twins with AFV discordance may progress to TTTS or IUGR in a significant proportion of cases. Of the non-TTTS groups, iOLIGO patients are more likely to progress to a TTTS-IUGR. Ultrasound examinations weekly for AFV assessment and monthly for fetal growth are indicated in non-TTTS patients.

OC30.03: Fetal intervention for congenital diaphragmatic hernia

Objective: One major problem in counselling couples with a prenatal diagnosis of a correctable fetal anomaly is the ability to exclude associated malformations that may modify the prognosis. Our aim was to assess the precision of fetal sonography in identifying isolated malformations. Methods: We retrospectively reviewed the prenatal and postnatal records of our center for cases with a prenatal diagnosis of an isolated fetal anomaly in the period 2002–2004. Results: The antenatal diagnosis of an isolated malformation was made in 151 cases. In one of this cases the anomaly disappeared in utero. Of the remaining cases, the prenatal diagnosis was confirmed after birth in 135 (90%). In 5 fetuses (all with a suspected coarctation of the aorta) the prenatal diagnosis was not confirmed. In 10 fetuses (6.7%) additional malformations were detected at postnatal or post-mortem. In 7 of these cases the anomalies were mild or would not have changed the prognosis. In 3 cases (2%) severe anomalies were present (1 hypoplasia of the corpus callosum with ventriculomegaly, one tracheal agenesis, one multiple anomalies). Two of these infants died. Conclusions: the prenatal diagnosis of an isolated fetal anomaly is highly reliable. However, the probability that additional malformations will go undetected albeit small remains tangible. In our experience, it was 2%.

OC085a: Selective fetocide in monochorionic twins: Oral communication abstracts

differences were found in blood pressure, stiffness, in endothelium dependent and independent vasodilatation between the two groups. Conclusions: IUGR caused by placental insufficiency appears to be associated with impaired vascular growth persisting into young adulthood. The smaller aortic dimensions and higher resting heart rate seen in both males and females of the IUGR group and the lower aortic compliance coefficient seen in male adolescents may influence the future cardiovascular health in these individuals.

OC121: Persistent elevation of cell‐free fetal DNA levels in maternal plasma following selective laser coagulation of chorionic plate anastomoses in twin–twin transfusion syndrome

been extensively studied. The aim of our study was to identify predictive factors of miscarriage or preterm delivery in TTTS treated by fetoscopic laser. Material and Methods: This is an observational study of 137 severe cases of TTTS diagnosed before 26 w treated by laser. Exclusion criteria were – elective preterm delivery for maternal or fetal indications before 34 w and intrauterine death of both fetuses. Transvaginal US measurement of cervical length was performed within 24 hours before laser treatment. Results: The median gestational age at diagnosis and delivery was 145 days (132–157) and 238 days (204–247) respectively. The mean cervical length measured before the procedure was 27.2, 32.0, 35.3, 33.2 and 38.1 mm in patients delivering < 24 w, at 24-27 w, 28–31, 32–33 and > 34 w respectively (p < 0.001). 43.8% and 56.3% of patients staged I-II and II-III delivered < 34 w (NS). The mean value of the deepest vertical pool (dvp) in the recipient’s sac was 118 and 117 in the groups delivering before 34 w and after 34 w (NS).The dvp was 124 mm in multiparous women and 110 mm in nulliparous women (P = 0.001).There was intra-uterine death of one twin in 39.7% and 60.3% of the patients delivering before and after 34 w respectively (P = 0.03). 9 patients required cervical cerclage, 6 nulliparous and 3 multiparous women. For a cervical length of less than 25 mm, the risk to deliver < 34 w was 80%. Logistic regression analysis identified 3 independent risk factors for preterm delivery: cervical length, cervical cerclage and multiparity. The death of one twin was protective against premature delivery. Conclusion: Cervical length before treatment has as significant impact on gestational age at delivery in TTTS treated by laser. Multiparous women expecting monochorionic twins complicated by TTTS have a higher risk for preterm labor.