Factors influencing the choice-of-care pathway and survival in the fetus with hypoplastic left heart syndrome in New Zealand: a population-based cohort study

OBJECTIVES

To better understand the relative influence of fetal and maternal factors in determining the choice-of-care pathway (CCP) and outcome in the fetus with hypoplastic left heart syndrome (HLHS).

DESIGN

A retrospective, population-based study of fetuses with HLHS from a national dataset with near-complete case ascertainment from 20 weeks' gestation. Fetal cardiac and non-cardiac factors were recorded from the patient record and maternal factors from the national maternity dataset. The primary endpoint was a prenatal decision for active treatment after birth (intention-to-treat). Factors associated with a delayed diagnosis (≥24 weeks' gestation) were also reviewed. Secondary endpoints included proceeding to surgical treatment, and 30-day postoperative mortality in liveborns with an intention-to-treat.

SETTING

New Zealand population-wide.

PARTICIPANTS

Fetuses with a prenatal diagnosis of HLHS between 2006 and 2015.

RESULTS

Of 105 fetuses, the CCP was intention-to-treat in 43 (41%), and pregnancy termination or comfort care in 62 (59%). Factors associated with intention-to-treat by multivariable analysis included a delay in diagnosis (OR: 7.8, 95% CI: 3.0 to 20.6, p<0.001) and domicile in the maternal fetal medicine (MFM) region with the most widely dispersed population (OR: 5.3, 95% CI: 1.4 to 20.3, p=0.02). Delay in diagnosis was associated with Māori maternal ethnicity compared with European (OR: 12.9, 95% CI: 3.1 to 54, p<0.001) and greater distance from the MFM centre (OR: 3.1, 95% CI: 1.2 to 8.2, p=0.02). In those with a prenatal intention-to-treat, a decision not to proceed to surgery was associated with maternal ethnicity other than European (p=0.005) and the presence of major non-cardiac anomalies (p=0.01). Thirty-day postoperative mortality occurred in 5/32 (16%) and was more frequent when there were major non-cardiac anomalies (p=0.02).

CONCLUSIONS

Factors associated with the prenatal CCP relate to healthcare access. Anatomic characteristics impact treatment decisions after birth and early postoperative mortality. The association of ethnicity with delayed prenatal diagnosis and postnatal decision-making suggests systemic inequity and requires further investigation.

Antenatal Detection of Treatable Critical Congenital Heart Disease Is Associated with Lower Morbidity and Mortality

OBJECTIVE

To establish the impact that timing of diagnosis and place of birth have on neonatal outcomes in those with readily treatable critical congenital heart disease.

STUDY DESIGN

This was a population-based study with a complete national cohort of live-born infants with transposition of the great arteries and aortic arch obstruction in New Zealand between 2006 and 2014. Timing of diagnosis, place of birth, survival to surgery, in-hospital events, and neonatal mortality were reviewed. Live births with a gestation of ≥35 weeks and without associated major extracardiac anomalies were included for analysis.

RESULTS

A total of 166 live-born infants with transposition of the great arteries and 87 with aortic arch obstruction were included. Antenatal detection increased from 32% in the first 3 years to 47% in the last 3 years (P = .05). During the same period, neonatal mortality decreased from 9% to 1% (P = .02). No deaths occurred after surgical intervention. An antenatal diagnosis was associated with decreased mortality (1/97 [1%] vs 11/156 [7%]; P = .03) and birth outside the surgical center was associated with increased risk of mortality (11/147 [7%] vs 1/106 [1%]; P = .02). Those with an antenatal diagnosis required fewer hours of mechanical ventilation (P = .02) and had shorter durations of hospital stay (P = .05) compared with those diagnosed >48 hours after birth.

CONCLUSIONS

The mortality risk for transposition of the great arteries and critical aortic arch obstruction is greatest before cardiac surgery. Improved antenatal detection allowing delivery at a surgical center is associated with reduced mortality.

Maternal lipid profile and the relation with spontaneous preterm delivery: a systematic review

BACKGROUND

It is unknown whether an unfavorable (atherogenic) lipid profile and homocysteine level, which could supersede clinical cardiovascular disease, is also associated with an increased risk of spontaneous preterm delivery (sPTD). A systematic review of studies assessing the lipid profile and homocysteine value of women with sPTD compared to women with term delivery in pre-pregnancy and during pregnancy.

METHODS

A systematic search of peer-reviewed articles published between January 1980 and May 2014 was performed using MEDLINE, EMBASE and the Cochrane database. We included case-control and cohort studies that examined triglycerides, high/low density lipoprotein cholesterol, total cholesterol and homocysteine in women with sPTD. Articles were subdivided in pre-pregnancy, first, second and third trimester. Of 708 articles reviewed for eligibility, 14 met our inclusion criteria.

RESULTS AND CONCLUSION

Nine cohort studies and five case-control studies were analyzed, reporting on 1466 cases with sPTD and 11296 controls with term delivery. The studies suggest a possible elevated risk of sPTD in woman with high TG levels, no association of high and low density lipoprotein cholesterol with the risk of sPTD was found. High homocysteine levels are associated with sPTD in the second trimester. The role of triglycerides and homocysteine in sPTD should be explored further.

Midtrimester preterm prelabour rupture of membranes (PPROM): expectant management or amnioinfusion for improving perinatal outcomes (PPROMEXIL - III trial)

Background

Babies born after midtrimester preterm prelabour rupture of membranes (PPROM) are at risk to develop neonatal pulmonary hypoplasia. Perinatal mortality and morbidity after this complication is high. Oligohydramnios in the midtrimester following PPROM is considered to cause a delay in lung development. Repeated transabdominal amnioinfusion with the objective to alleviate oligohydramnios might prevent this complication and might improve neonatal outcome.

Methods/Design

Women with PPROM and persisting oligohydramnios between 16 and 24 weeks gestational age will be asked to participate in a multi-centre randomised controlled trial. Intervention: random allocation to (repeated) abdominal amnioinfusion (intervention) or expectant management (control). The primary outcome is perinatal mortality. Secondary outcomes are lethal pulmonary hypoplasia, non-lethal pulmonary hypoplasia, survival till discharge from NICU, neonatal mortality, chronic lung disease (CLD), number of days ventilatory support, necrotizing enterocolitis (NEC), periventricular leucomalacia (PVL) more than grade I, severe intraventricular hemorrhage (IVH) more than grade II, proven neonatal sepsis, gestational age at delivery, time to delivery, indication for delivery, successful amnioinfusion, placental abruption, cord prolapse, chorioamnionitis, fetal trauma due to puncture. The study will be evaluated according to intention to treat. To show a decrease in perinatal mortality from 70% to 35%, we need to randomise two groups of 28 women (two sided test, β-error 0.2 and α-error 0.05).

Discussion

This study will answer the question if (repeated) abdominal amnioinfusion after midtrimester PPROM with associated oligohydramnios improves perinatal survival and prevents pulmonary hypoplasia and other neonatal morbidities. Moreover, it will assess the risks associated with this procedure.

Trial registration

NTR3492 Dutch Trial Register (http://www.trialregister.nl).

[Perinatal policy in cases of extreme prematurity; an investigation into the implementation of the guidelines]

OBJECTIVE

To determine to what extent the recommendations to actively treat preterm infants with a gestational age of 24 weeks upwards laid down in the guidelines 'Perinatal policy in cases of extreme prematurity' have influenced policy in Dutch perinatal centres in the first year after publication, and what the health outcomes were.

DESIGN

Retrospective, descriptive study.

METHOD

Our study population included all pregnant women who were admitted to a perinatal centre at 23 5/7 to 26 weeks gestation with a diagnosis of 'threatened preterm labour', and their preterm infants. We collected both obstetric data and data on survival and morbidity of the infants from the medical files.

RESULTS

Of a total of 192 preterm infants 185 (96%) were born alive; 92% of these infants were admitted to the neonatal intensive care unit. Survival rates were 43% and 61% at 24 weeks and 25 weeks gestation, respectively. Short-term morbidity (bronchopulmonary dysplasia, retinopathy of the newborn, severe intraventricular haemorrhage, necrotising enterocolitis and persistent ductus arteriosus) occurred in 79% and 71% of the infants born at 24 weeks and 25 weeks gestation, respectively.

CONCLUSIONS

The recommendations from these guidelines have been implemented swiftly in Dutch perinatal centres, and survival of extremely preterm infants has increased. This has imposed a considerable burden on the capacity of these centres. Little is yet known about the long-term (up to school-age) health and survival of these infants.

[Practice guideline 'Perinatal management of extremely preterm delivery']

At the request of the State Secretary of the Dutch Ministry of Health, Welfare and Sport a national multidisciplinary workgroup developed an evidence-based practice guideline for the management of pregnant women with an imminent preterm delivery after a pregnancy of less than 26 weeks duration and for extremely preterm neonates. Active care measures are advised for neonates from a gestational age of 24 0/7 weeks onwards, unless there are serious arguments that justify a conservative management. In cases of imminent preterm delivery, intrauterine transport to a perinatological care centre is advised from a gestational age of 23 4/7 weeks onwards. In cases of imminent preterm delivery, glucocorticoids to enhance fetal lung maturity should be administered from a gestational age of 23 5/7 weeks onwards. From a gestational age of 24 0/7 weeks onwards a caesarean section may be considered if the fetal condition during spontaneous labour justifies this.

The Roach muscle bundle and umbilical cord coiling

OBJECTIVE

To determine if presence of the Roach muscle, a small muscle bundle lying just beside the umbilical artery, contributes to umbilical cord coiling.

METHODS

251 umbilical cords were examined. The umbilical coiling index (UCI) was calculated as the number of coils divided by the cord length in cm. Cords were classified as hypocoiled (UCI<p10), normocoiled (UCI p10-p90) or hypercoiled (UCI>p90). On microscopic examination of a cross section of the cord, absence or presence of a Roach muscle was determined. The t-test for independent samples and logistic regression were used for statistical analysis.

RESULTS

A Roach muscle was observed in 101 cords. The mean UCI was higher in cords with the muscle bundle (0.23 coils/cm) than in cords without a muscle (0.18 coils/cm). Difference in mean: 0.05 coils/cm (95% C.I. 0.01-0.09). OR for hypercoiling in presence of the muscle was 2.98 (95% C.I. 1.57-5.64). OR for hypocoiling in the presence of the muscle was 1.49 (95% C.I. 0.79-2.81).

CONCLUSIONS

Our results suggest that presence of a Roach muscle bundle contributes to umbilical cord coiling. Given the divergence in umbilical cord coiling within subgroups with or without this muscle, other factors must play a more dominant role.

Hypercoiling of the umbilical cord and placental maturation defect: associated pathology?

Our objective was to determine whether there is an association between hypercoiling of the umbilical cord and placental maturation defect. From a database comprising 1147 cases, containing data on all placentas examined at our institution during the study period, we selected all cases with a gestational age of at least 37 weeks that exhibited hypercoiling of the umbilical cord (coiling density above the 90th percentile, n = 42); we also examined 2 matched controls for each case, one with hypocoiling and one with normocoiling. The mean number of syncytiocapillary membranes (SCM) per terminal villus was calculated. Presence of a placental maturation defect was defined as the mean number of SCM below the 10th percentile. Correlations were assessed using Spearman's rho. Relations between dichotomous variables were tested using logistic regression. Mean number of SCM per terminal villus (+/-standard deviation) was 1.25 +/- 0.65. Difference in mean between hypo- and hypercoiled cords was 0.37 (95% confidence interval [CI], 0.07 to 0.67). The correlation coefficient between mean number of SCM and umbilical coiling index (UCI, coils/cm) was -0.28 (P = 0.002). The odds ratio (OR) for placental maturation defect in presence of hypercoiling was 2.61 (95% CI, 0.75 to 9.12). The OR for fetal death was 132 (95% CI, 13.2 to 1315) in the presence of a placental maturation defect and 5.49 (95% CI, 1.02 to 29.6) in the presence of hypercoiling. The OR for indication of fetal hypoxia/ischemia was 12.3 (95% CI, 3.0 to 50.3) in the presence of a placental maturation defect and 3.2 (95% CI, 0.95 to 10.9) in the presence of hypercoiling. We found a trend toward placental maturation defect in the presence of hypercoiling and an inverse relationship between the mean number of SCM in the terminal villi and the UCI. We confirmed associations between fetal death and both a maturation defect and hypercoiling and found an association between histological indication of fetal hypoxia/ischemia and a placental maturation defect.

The umbilical coiling index in complicated pregnancy

OBJECTIVE

To evaluate umbilical cord coiling in pregnancies with adverse outcome.

STUDY DESIGN

Umbilical cords and hospital records of 565 consecutive cases with an indication for histological examination of the placenta were studied. The umbilical coiling index (UCI) was determined as the number of complete coils divided by the length of the cord in centimeters, by an observer blinded for pregnancy outcome. Data on obstetric history and pregnancy outcome of each case were obtained from the hospital records. We calculated odds ratios and their 95% confidence interval to evaluate the strength of associations between pregnancy outcome and abnormal cord coiling.

RESULTS

Fetal death (OR 4.09, 95% CI 2.22-7.55), chorioamnionitis (OR 1.77, 95% CI 1.09-2.88), fetal structural or chromosomal abnormalities (OR 1.78, 95% CI 1.08-2.95), and lower Apgar score at 5 min (p=0.03) were associated with undercoiling (UCI below the 10th percentile, using reference values from uncomplicated pregnancies). Fetal death (OR 3.74, 95% CI 1.89-7.40), iatrogenic preterm delivery (OR 1.91, 95% CI 1.04-3.49), umbilical arterial pH<7.05 (OR 3.63, 95% CI 1.44-9.17), fetal structural or chromosomal abnormalities (OR 1.79, 95% CI 1.01-3.16), thrombosis in fetal placental vessels (OR 2.64, 95% CI 1.37-5.06), chronic fetal hypoxia/ischemia (OR 1.82, 95% CI 1.09-3.05), and lower weight for gestational age (p=0.01) were associated with overcoiling (UCI above the 90th percentile).

CONCLUSIONS

Our findings confirm that adverse perinatal outcome is associated with both undercoiling and overcoiling of the umbilical cord.

Umbilical coiling index in normal and complicated pregnancies

OBJECTIVE

To estimate the relation between undercoiling and overcoiling of the umbilical cord and adverse pregnancy outcome.

METHODS

Umbilical cords and hospital records of 885 patients were studied in a cross-sectional study design. The umbilical coiling index was determined as the number of complete coils divided by the length of the cord in centimeters, blinded for pregnancy outcome. Obstetric history and pregnancy outcome of each patient were obtained from hospital records, blinded for the umbilical coiling index. Odds ratios and their 95% confidence intervals were calculated to evaluate associations between undercoiling and overcoiling and adverse pregnancy outcome, using multiple logistic regression.

RESULTS

Undercoiling (umbilical coiling index below the 10th percentile, using references values from uncomplicated pregnancies) was associated with fetal death (odds ratio [OR] 3.35, 95% confidence interval [CI] 1.48-7.63), spontaneous preterm delivery (OR 2.16, 95% CI 1.34-3.48), trisomies (OR 5.79, 95% CI 2.07-16.24), low Apgar score at 5 minutes (OR 3.14, 95% CI 1.47-6.70), velamentous cord insertion (OR 3.00, 95% CI 1.16-7.76), single umbilical artery (OR 3.68, 95% CI 1.26-10.79), and dextral coiling (OR 1.80, 95% CI 1.02-3.17). Overcoiling (umbilical coiling index above the 90th percentile) was associated with asphyxia (OR 4.16, 95% CI 1.30-13.36), umbilical arterial pH < 7.05 (OR 2.91, 95% CI 1.05-8.09), small for gestational age infants (OR 2.10, 95% CI 1.01-4.36), trisomies (OR 9.26, 95% CI 2.84-30.2), single umbilical artery (OR 8.25, 95% CI 2.60-26.12), and sinistral coiling (OR 4.30, 95% CI 1.52-12.2).

CONCLUSION

Undercoiling and overcoiling of the umbilical cord are associated with increased risk for adverse perinatal outcome.

The umbilical coiling index, a review of the literature

Our aim was to review the literature on umbilical cord coiling. Relevant articles in English published between 1966 and 2003 were retrieved by a Medline search and cross-referencing. The normal umbilical cord coiling index (UCI) is 0.17 (+/- 0.009) spirals completed per cm. Abnormal cord coiling, i.e. UCI <10th centile (<0.07) or >90th centile (>0.30) is associated with adverse pregnancy outcome. Hypocoiling of the cord is associated with increased incidence of fetal demise, intrapartum fetal heart rate decelerations, operative delivery for fetal distress, anatomic-karyotypic abnormalities and chorio-amnionitis. Hypercoiling of the cord is associated with increased incidence of fetal growth restriction, intrapartum fetal heart rate decelerations, vascular thrombosis and cord stenosis. It is not clear whether abnormal coiling is actually a cause of pathology, or merely one of the sequelae, or both. We discuss the theories involving the cause of cord coiling, and the consequences of the degree of cord coiling on blood flow through the umbilical vessels. In the future ultrasonographic evaluation of the umbilical cord and the UCI may become an integral part of fetal assessment in high-risk pregnancies.