K. E. A. Hack

Increased Stillbirth in Uncomplicated Monochorionic Twin Pregnancies A Systematic Review and Meta-analysis

OBJECTIVE: To estimate the risk of stillbirth in apparently uncomplicated monochorionic–diamniotic twin pregnancies by systematic review and meta-analysis and compare it with that in uncomplicated dichorionic pregnancies. DATA SOURCES: We performed an electronic search (January 1985 to April 2012) of Medline, PubMed, Embase, and ClinicalTrials.gov databases. METHODS OF STUDY SELECTION: Studies detailing gestational-age specific stillbirth rates after 24 weeks of gestation in monochorionic–diamniotic twin pregnancies uncomplicated by twin–twin transfusion syndrome, growth restriction, or major anomalies. The rate and risk of stillbirth were calculated in 2-week gestational age blocks and compared in controlled studies with dichorionic pregnancies. TABULATION, INTEGRATION, AND RESULTS: We evaluated 361 studies to include nine informative studies, four after additional data from the investigators. The rate of stillbirth per 1,000 uncomplicated monochorionic–diamniotic pregnancies at 32–33, 34–35, and 36–37 weeks of gestation was 5.1, 6.8, and 6.2, respectively. The risk of stillbirth per pregnancy at 32, 34, and 36 weeks of gestation was 1.6%, 1.3% and 0.9%, respectively. Compared with uncomplicated dichorionic pregnancies, the odds ratio for stillbirth per pregnancy at 32, 34, and 36 weeks of gestation was 4.2 (95% confidence interval [CI] 1.4–12.6), 3.7 (CI 1.1–12.0), and 8.5 (CI 1.6–44.7), respectively. CONCLUSION: Uncomplicated monochorionic twin pregnancies are at substantial risk of stillbirth throughout the third trimester, which is severalfold higher than in dichorionic twin pregnancies. Given the risk of fetal death to the cotwin, these data should inform decisions around timing of delivery in seemingly normal monochorionic twin pregnancies.

Prospective risk of stillbirth and neonatal complications in twin pregnancies: systematic review and meta-analysis

Objective To determine the risks of stillbirth and neonatal complications by gestational age in uncomplicated monochorionic and dichorionic twin pregnancies. Design Systematic review and meta-analysis. Data sources Medline, Embase, and Cochrane databases (until December 2015). Review methods Databases were searched without language restrictions for studies of women with uncomplicated twin pregnancies that reported rates of stillbirth and neonatal outcomes at various gestational ages. Pregnancies with unclear chorionicity, monoamnionicity, and twin to twin transfusion syndrome were excluded. Meta-analyses of observational studies and cohorts nested within randomised studies were undertaken. Prospective risk of stillbirth was computed for each study at a given week of gestation and compared with the risk of neonatal death among deliveries in the same week. Gestational age specific differences in risk were estimated for stillbirths and neonatal deaths in monochorionic and dichorionic twin pregnancies after 34 weeks’ gestation. Results 32 studies (29 685 dichorionic, 5486 monochorionic pregnancies) were included. In dichorionic twin pregnancies beyond 34 weeks (15 studies, 17 830 pregnancies), the prospective weekly risk of stillbirths from expectant management and the risk of neonatal death from delivery were balanced at 37 weeks’ gestation (risk difference 1.2/1000, 95% confidence interval −1.3 to 3.6; I2=0%). Delay in delivery by a week (to 38 weeks) led to an additional 8.8 perinatal deaths per 1000 pregnancies (95% confidence interval 3.6 to 14.0/1000; I2=0%) compared with the previous week. In monochorionic pregnancies beyond 34 weeks (13 studies, 2149 pregnancies), there was a trend towards an increase in stillbirths compared with neonatal deaths after 36 weeks, with an additional 2.5 per 1000 perinatal deaths, which was not significant (−12.4 to 17.4/1000; I2=0%). The rates of neonatal morbidity showed a consistent reduction with increasing gestational age in monochorionic and dichorionic pregnancies, and admission to the neonatal intensive care unit was the commonest neonatal complication. The actual risk of stillbirth near term might be higher than reported estimates because of the policy of planned delivery in twin pregnancies. Conclusions To minimise perinatal deaths, in uncomplicated dichorionic twin pregnancies delivery should be considered at 37 weeks’ gestation; in monochorionic pregnancies delivery should be considered at 36 weeks. Systematic review registration PROSPERO CRD42014007538.

The value of umbilical artery Doppler velocimetry in the antenatal surveillance of uncomplicated monochorionic twin pregnancies

To investigate the predictive value of abnormal umbilical artery Doppler findings on outcome in uncomplicated monochorionic (MC) twin pregnancies.

Long-term outcome in relationship to neonatal transfusion volume in extremely premature infants: a comparative cohort study.

BackgroundIn premature born infants red blood cell (RBC) transfusions have been associated with both beneficial and detrimental sequels. Upon RBC transfusion, improvement in cerebral blood flow and oxygenation have been observed, while a more liberal transfusion policy may be associated with a better developmental outcome. The effect of the transfusion volume on long-term outcome is not known.MethodsObservational follow-up study of a cohort of extremely premature born infants, treated in 2 neonatal intensive care units using a different transfusion volume (15 ml/kg in Unit A and 20 ml/kg in Unit B). The primary outcome was a composite of post discharge mortality, neuromotor developmental delay, blindness or deafness, evaluated at a mean corrected age (CA) of 24 months related to the transfusion volume/kg bodyweight administered during the postnatal hospital stay.ResultsDespite the difference in transfusion volume in clinically comparable groups of infants, they received a similar number of transfusions (5.5 ± 3.2 versus 5.5 ± 2.3 respectively in Unit A and B). The total transfused volume in unit A was 79 ± 47 ml/kg and 108 ± 47 ml/kg in unit B (p = 0.02). Total transfused RBC volume per kg bodyweight was not an independent predictor of the composite outcome (p = 0.96, OR 1.0 (CI 0.9-1.1).ConclusionThere was no relationship between the composite outcome at 24 months CA and transfusion volume received during the post natal hospital stay. As there was no clinical advantage of the higher transfusion volume, a more restrictive volume will reduce total transfusion volume and donor exposure. Future research on the optimal transfusion volume per event to extreme preterm infants should include larger, prospective studies with a longer follow-up period through to childhood or even adolescence.

A comparative cohort study on transfusion practice and outcome in two Dutch tertiary neonatal centres.

The objective of this study was to investigate how a red blood cell transfusion volume of 15 or 20 mL kg−1 body weight affects the total number of administered transfusions and neonatal complications in premature infants born before 32 gestational weeks. In this observational study, we analysed clinical data from two cohorts of 218 and 241 premature infants admitted to two neonatal centres which used the same transfusion guideline and product, but different transfusion volumes. Outcome parameters were the number of administered transfusions and the composite outcome of bronchopulmonary dysplasia, retinopathy of prematurity, intraventricular haemorrhage and mortality. The proportion of transfused infants was significantly lower (59 vs. 77%) in the centre using a lower transfusion volume of 15 mL kg−1. In infants born between a gestational age of 24 0/7 weeks and 27 6/7 weeks. a similar proportion received transfusions in both centres, with an equal number of transfusions per infant. In infants born between a gestational age of 28 0/7 weeks and 31 6/7 weeks, the proportion of transfused infants (49 vs. 74%) was significantly higher in the centre using a larger transfusion volume. In these infants, transfusion with 20 mL kg−1 resulted, however, in a mean reduction of one transfusion episode per infant. The higher proportion of transfused infants was associated with a higher pre‐transfusion haematocrit in less ill infants, suggesting the use of different triggers based on clinical grounds. Composite clinical complications were similar in both cohorts. Clinical neonatal outcome was similar disregard of a higher proportion of transfused patients and a higher total amount of RBC transfused in one of the centres. A larger transfusion volume of 20 mL kg−1 prolonged the interval until next transfusion and can reduce donor exposure in infants born between a gestational age of 28 0/7 weeks and 31 6/7 weeks.

Perinatal outcome of monochorionic and dichorionic twins after spontaneous and assisted conception: a retrospective cohort study

The aim of this study was to compare pregnancy outcomes in twin pregnancies after assisted conception and spontaneous conception, according to chorionicity.