Assessment of left ventricular function using the Myocardial Performance Index in term fetuses that develop intrapartum compromise.

OBJECTIVE: To investigate the relationship between the prelabour left ventricular Myocardial Performance Index (LVMPI) and intrapartum fetal compromise (IFC) in low-risk term pregnancies. METHODS: A blinded, prospective observational cohort study at the Mater Mother's Hospital, Brisbane, Australia. A cohort of 284 women with uncomplicated singleton pregnancies underwent fortnightly ultrasound from 36 weeks until delivery. The LVMPI was assessed by conventional Doppler ultrasound and correlated with intrapartum outcomes. The LVMPI was also correlated with other Doppler indices of fetal wellbeing. RESULTS: Two hundred and seventy-three women were included in the final analysis, the median LVMPI was higher in fetuses that required any emergency operative delivery for IFC (0.56, 0.52-0.60 versus 0.54, 0.50-0.58, p = .007). The left ventricular cardiac output (LVCO) and cerebroplacental ratio (CPR) were lower in fetuses that required any emergency operative delivery for IFC compared to those that did not (164 ± 19 ml/min/kg versus 181 ± 30 ml/min/kg, p < .001) (1.63 + 0.30 versus 1.90 + 0.50, p < .001), respectively. The LVMPI was inversely correlated with the CPR (r = -0.20, p < .01), MCA PI (r = -0.29, p < .01), and LVCO (r = -0.22, p < .01). CONCLUSIONS: Higher global LVMPI is associated with a higher risk for IFC and poorer condition of the newborn.

Prelabour myocardial deformation and cardiac output in fetuses that develop intrapartum compromise at term: a prospective observational study.

Objective: Redistribution of cardiac output is responsible for the "brain sparing" effect seen during periods of acute or chronic fetal stress. We investigated the relationship between prelabour cardiac function in fetuses that subsequently developed intrapartum fetal compromise (IFC). Methods: A blinded, prospective, observational, cohort study, at Mater Mother's Hospital, Brisbane, Australia. A cohort of 284 women with uncomplicated singleton pregnancies underwent ultrasound every 2 weeks from 36 weeks until delivery. Fetal cardiac output was assessed by conventional Doppler ultrasound and myocardial deformation was measured using velocity vector imaging. Results: Two hundred and seventy three women were included in the final analysis, of which 19% had an emergency operative delivery for intrapartum fetal compromise (IFC). Global left ventricular strain (-12.1%, interquartile ranges (IQR) - 10.3 to -14% versus 13%, IQR -11.3 to -14.2%, p = .01) and strain rate (-1.00, IQR 0.85-1.16 s-1 versus -1.11, IQR -1.00 to -1.21 s-1, p < .001) were lower in fetuses that required any emergency operative delivery for IFC compared to those that did not. Global longitudinal right ventricular strain rate was lower in fetuses that developed IFC (-1.04 ± 0.22 s-1 versus 1.13 ± 0.22 s-1, p < .001), whereas global right ventricular strain did not show any significance differences between the two groups. Additionally, left ventricular cardiac output was lower in fetuses that developed IFC or had a composite neonatal morbidity (560 ± 44 mL/min versus 617 ± 72 mL/min, p < .001) or (581 ± 44 mL/min versus 612 ± 72 mL/min, p < .01), respectively. Conclusion: Lower global left ventricular strain and strain rate and cardiac output are associated with IFC and poorer condition of the newborn. Assessment of fetal cardiac function may be useful for risk stratification for intrapartum fetal compromise in apparently "low risk" term pregnancies.

Obstetric and perinatal outcomes in pregnancies with isolated foetal congenital heart abnormalities.

Objective: To determine obstetric, intrapartum, and perinatal outcomes for pregnancies with isolated foetal congenital heart defects (CHDs). Methods: This was a retrospective cohort study of women that delivered an infant with an isolated major CHD between January 2010 and April 2017 at a major Australian perinatal centre. The study cohort was compared with a cohort of women with infants without CHD. Cardiac abnormalities were broadly subdivided into the following five categories using the International Classification of Diseases Tenth Revision (ICD-10) as a guide - transposition of the great arteries (TGA), septal defects, right heart lesions (RHL), left heart lesions (LHL), and "other". Demographic characteristics and obstetric, intrapartum, and perinatal outcomes were compared between the two cohorts. Results: The final study cohort comprised of 342 infants with isolated CHD and 68,911 controls. Of the infants with CHD, 20.4% (70/342) had transposition of the great vessels, 23% (79/342) had septal lesions, 14.6% (50/342) had right sided lesions, 23.3% (80/342) left sided, and 18.4% (63/342) categorised as "other". Women with foetal CHD had a higher BMI and had higher rates of cardiac disease, diabetes mellitus, and hypertension, be smokers and consume alcohol compared to controls. The CHD cohort had lower odds of spontaneous vaginal delivery (SVD) (OR 0.73, 95%CI 0.58-0.90) and higher odds of caesarean for nonreassuring foetal status (aOR 1.65, 95%CI 1.07-2.55), birth weight <5th (aOR 3.44, 95%CI 2.38-4.98) and <10th (aOR 2.49, 95%CI 1.82-3.40) centiles, neonatal intensive care unit (NICU) admission (aOR 109.14, 95%CI 74.44-160.02), severe respiratory distress (aOR 2.90, 95%CI 2.33-3.76), 5 minutes Apgar score <7 (aOR 2.48, 95%CI 1.46-4.20), severe acidosis (aOR 1.80, 95%CI 1.14-2.85), stillbirth (aOR 4.09, 95%CI 1.62-10.33), neonatal death (aOR 24.30, 95%CI 13.24-44.61), and overall perinatal death (aOR 13.42, 95%CI 8.08-22.30). Infants with TGA had the lowest overall risk of complications whilst infants with RHL, LHL, and "others" had the highest risk of adverse outcomes, particularly death. Conclusion: Infants with CHD have overall worse obstetric and perinatal outcomes compared with controls. Infants with TGA have the best perinatal outcomes of all the CHD subcategories.