Perinatal mortality and mode of delivery in monochorionic diamniotic twin pregnancies ≥ 32 weeks of gestation: a multicentre retrospective cohort study.

OBJECTIVE: To study perinatal mortality rates in a cohort of 465 monochorionic (MC) twins without twin-twin transfusion syndrome (TTS) born at 32 weeks of gestation or later since reported interauterine fetal death (IUFD) rates >32 weeks of gestations in the literature vary, leading to varying recommendations on the optimal timing of delivery, and to investigate the relation between perinatal mortality and mode of delivery. DESIGN: Multicentre retrospective cohort study. SETTING: Ten perinatal referral centres in the Netherlands. POPULATION: All MC twin pregnancies without TTTS delivered at ≥ 32 weeks of gestation between January 2000 and December 2005. METHODS: The medical records of all MC twin pregnancies without TTTS delivered at the ten perinatal referral centres in the Netherlands between January 2000 and December 2005 were reviewed. MAIN OUTCOME MEASURES: Perinatal mortality in relation to gestational age and mode of delivery at ≥ 32 weeks of gestation. RESULTS: After 32 weeks of gestation, five out of 930 fetuses died in utero and there were six neonatal deaths (6 per 1000 infants). In women who delivered ≥ 37 weeks, perinatal mortality was 7 per 1000 infants. Trial of labour was attempted in 376 women and was successful in 77%. There were three deaths in deliveries with a trial of labour (8 per 1000 deliveries), of which two were related to mode of delivery. Infants born by caesarean section without labour had an increased risk of neonatal morbidity and respiratory distress syndrome. CONCLUSIONS: In MC twin pregnancies the incidence of intrauterine fetal death is low ≥ 32 weeks of gestation. Therefore, planned preterm delivery before 36 weeks does not seem to be justified. The risk of intrapartum death is also low, at least in tertiary centres.

Placental characteristics of monoamniotic twin pregnancies in relation to perinatal outcome.

OBJECTIVE: To study placental characteristics in relation to perinatal outcome in 55 pairs of monochorionic monoamniotic (MA) twins. METHODS: Between January 1998 and May 2008 55 pairs of MA twins were delivered in 4 tertiary care centers and analysed for mortality, birth weight discordancy and twin-to-twin transfusion syndrome (TTTS) in relation to type of anastomoses, type and distance between cord insertions and placental sharing. Five acardiac twins, 2 conjoined twins, 4 higher order multiples and one early termination of pregnancy were excluded, leaving 43 MA placentas for analysis. Of these 43, one placenta could not be analysed for placental vascular anastomoses due to severe maceration after single intra-uterine demise leaving 42 placentas for analysis of anastomoses. RESULTS: Arterio-arterial (AA), venovenous (VV) and arteriovenous (AV) anastomoses were detected in 98%, 43% and 91% of MA placentas, respectively. Velamentous cord insertion was found in 4% of cases. Small distance between both umbilical cord insertions (<5 cm) was present in 53% of MA placentas. Overall perinatal loss rate was 22% (19/86). We found no association between mortality and type of anastomoses, type and distance between cord insertions and placental sharing. The incidence of TTTS was low (2%) and occurred in the only pregnancy with absent AA-anastomoses. CONCLUSION: Perinatal mortality in MA twins was not related to placental vascular anatomy. The almost ubiquitous presence of compensating AA-anastomoses in MA placentas appears to prevent occurrence of TTTS.

[Tertiary obstetric care: the aims of the planning decree on perinatal care of 2001 have not yet been achieved]. / Derdelijns verloskundige zorg: doelstellingen van het 'planningsbesluit bijzondere perinatologische zorg' uit 2001 nog niet gehaald.

OBJECTIVE: To compare the actual situation in tertiary perinatal care in the Netherlands with the objectives laid down in the 2001 decree on perinatal care by the Dutch Ministry of Health, Welfare and Sport. DESIGN: Descriptive, retrospective. METHOD: Data on tertiary perinatal care, the transfer or refusal of women with very endangered pregnancies and the personnel of obstetric high care (OHC) units in 2006 were compared with the targets laid down in the planning decree on perinatal care and in a report by the Dutch Health Council from 2000. Parameters of tertiary perinatal care output were the number of admissions, and the number of beds in OHC units and neonatal intensive care units (NICU). RESULTS: In 2006, 128 of the 250 beds intended for OHC had been obtained. The degree of capacity utilisation was 94%, while the norm is 80%. 312 women were transferred due to lack of capacity of OHC units and NICU. The number of staff, specialised physicians as well as nurses, was considerably lower than the planned capacity. But training for obstetric perinatologists and OHC nurses was given. CONCLUSION: The targets for the number of beds for tertiary obstetric care and associated medical personnel have not been achieved as yet. As a consequence, the number of transfers is still too high. The funding of OHC units is not attuned to the complexity of tertiary perinatal care. Closer supervision of the execution of the planning decree and an adequate financing system are needed to achieve the objectives of the planning decree in the next 3 years.

Significance of donor anuria differs between monoamniotic and diamniotic twin-twin transfusion syndrome.

Development of severe twin-twin transfusion syndrome (TTTS) in diamniotic-monochorionic twins includes five stages of increasing severity, i.e. recipient polyhydramnios and donor oligohydramnios, donor anuria, abnormal umbilical flow velocities in either twin, hydrops in the recipient, and intrauterine fetal death (IUFD) in either or both twins. In a severe case of TTTS in monoamniotic twins we observed donor anuria to appear after hydrops in the recipient. We conclude that donor anuria is a late and serious symptom in monoamniotic TTTS.