Maternal hypertension and survival in singletons and twins born at 23-29 weeks: not just one answer…

Maternal Hypertension Disorders and Neonatal Acute Kidney Injury: Results from the AWAKEN Study

OBJECTIVE

This study aimed to examine the association between maternal hypertension (HTN) exposure and neonatal acute kidney injury (AKI).

STUDY DESIGN

Retrospective cohort study of 2,162 neonates admitted to 24 neonatal intensive care units (NICUs). Neonates were classified into the following exposure groups: any maternal HTN, chronic maternal HTN, preeclampsia/eclampsia, both, or neither. Demographics, clinical characteristics, and AKI status were compared using Chi-square and analysis of variance. General estimating logistic regression was used to estimate adjusted odds ratios and included a stratified analysis for site of delivery.

RESULT

Neonates exposed to any maternal HTN disorder had a tendency toward less overall and early AKI. When stratified by inborn versus outborn, exposure to both maternal HTN disorders was associated with a significantly reduced odds of early AKI only in the inborn neonates.

CONCLUSION

Exposure to maternal HTN, especially preeclampsia/eclampsia superimposed on chronic HTN, was associated with less likelihood of early AKI in the inborn group.

KEY POINTS

· Maternal HTN is associated with less neonatal AKI.. · Maternal HTN category is variably associated with AKI.. · Inborn status is an important contributor to this association..

Outcomes of singleton preterm very low birth weight infants born to mothers with pregnancy-induced hypertension

The association between maternal pregnancy-induced hypertension (PIH) and neonatal mortality and morbidities in preterm infants has not been consistent. This study aimed to evaluate the influence of maternal PIH on mortality and morbidities in singleton infants with very low birth weight born before 30 weeks of gestational age using the Korean Neonatal Network (KNN) database. A total of 5340 singleton infants with very low birth weight were registered in the KNN registry, who were born at 23⁺⁰ to 29⁺⁶ weeks of gestational age between January 2015 and December 2020. Baseline characteristics and neonatal mortality and morbidities were compared between infants with PIH and non-PIH mothers. After adjustment for potential confounders, infants with PIH mothers had significantly higher odds of respiratory distress syndrome (OR 1.983; 95% CI 1.285-3.061, p = 0.002) and bronchopulmonary dysplasia (OR 1.458; 95% CI 1.190-1.785, p < 0.001), and severe bronchopulmonary dysplasia (OR 1.411; 95% CI 1.163-1.713, p < 0.001) than infants with non-PIH mothers, while there were no significant differences in severe intraventricular hemorrhage, periventricular leukomalacia, retinopathy of prematurity, or death during neonatal intensive care unit admission between infants with PIH and non-PIH mothers. This study showed that preterm infants with PIH mothers had an increased risk of neonatal respiratory morbidities, including respiratory distress syndrome and bronchopulmonary dysplasia.

A Retrospective Cohort Study on Mortality and Neurodevelopmental Outcomes of Preterm Very Low Birth Weight Infants Born to Mothers with Hypertensive Disorders of Pregnancy

OBJECTIVE

We examined the effects of maternal hypertensive disorders of pregnancy (HDP) on the mortality and neurodevelopmental outcomes in preterm very low birth weight (VLBW) infants (BW ≤1,500 g) based on their intrauterine growth status and gestational age (GA).

STUDY DESIGN

We included singleton VLBW infants born at <32 weeks' gestation registered in the Neonatal Research Network Japan database. The composite outcomes including death, cerebral palsy (CP), and developmental delay (DD) at 3 years of age were retrospectively compared among three groups: appropriate for GA (AGA) infants of mothers with and without HDP (H-AGA and N-AGA) and small for GA (SGA) infants of mothers with HDP (H-SGA). The adjusted odds ratios (AOR) and 95% confidence intervals (CI) stratified by the groups of every two gestational weeks were calculated after adjusting for the center, year of birth, sex, maternal age, maternal diabetes, antenatal steroid use, clinical chorioamnionitis, premature rupture of membranes, non-life-threatening congenital anomalies, and GA.

RESULTS

Of 19,323 eligible infants, outcomes were evaluated in 10,192 infants: 683 were H-AGA, 1,719 were H-SGA, and 7,790 were N-AGA. Between H-AGA and N-AGA, no significant difference was observed in the risk for death, CP, or DD in any GA groups. H-AGA had a lower risk for death, CP, or DD than H-SGA in the 24 to 25 weeks group (AOR: 0.434, 95% CI: 0.202-0.930). The odds for death, CP, or DD of H-SGA against N-AGA were found to be higher in the 24 to 25 weeks (AOR: 2.558, 95% CI: 1.558-3.272) and 26 to 27 weeks (AOR: 1.898, 95% CI: 1.427-2.526) groups, but lower in the 30 to 31 weeks group (AOR: 0.518, 95% CI: 0.335-0.800).

CONCLUSION

There was a lack of follow-up data; however, the outcomes of liveborn preterm VLBW infants of mothers with HDP depended on their intrauterine growth status and GA at birth.

KEY POINTS

· The effects of HDP on preterm low birth weight infants need to be further examined.. · The outcomes were not different between AGA infants with and without maternal HDP.. · The outcomes of SGA infants with maternal HDP were dependent on their GA..

Mothers with hypertensive disorders of pregnancy increased risk of periventricular leukomalacia in extremely preterm or extremely low birth weight infants: A propensity score analysis

BACKGROUND

At present, the conclusions about the impact of hypertensive disorders of pregnancy (HDP) on the clinical outcomes of preterm infants are inconsistent. This study used the propensity score matching (PSM) analysis to evaluate the effect of HDP on clinical outcomes of extremely preterm or extremely low birth weight (EP/ELBW) infants.

METHODS

Retrospective analysis was performed on the EP/ELBW infants discharged from 26 tertiary neonatal intensive care units or died during hospitalization from 2008 to 2017, who were divided into HDP group and non-HDP group. The six covariates including sex, gestational age, birth weight, twin or multiple pregnancy, antenatal steroids administration, and conception method were matched through the PSM method at a ratio of 1:1. The survival rate at discharge and the major clinical complications were compared between the two groups.

RESULTS

After matching the six covariates, compared with the non-HDP group, there was no significant difference in the survival rate at discharge (64 vs. 63.2%, p > 0.05), the incidence of bronchopulmonary dysplasia (BPD) or moderate to severe BPD in the HDP group (58.3 vs. 54.9%, p > 0.05; 5.2 vs. 6.2%, p > 0.05). The incidence of periventricular leukomalacia (PVL) in the HDP group was significantly increased (5.7 vs. 1.9%, p < 0.05).

CONCLUSIONS

HDP increased the risk of PVL in EP/ELBW infants, but had no significant effect on the survival rate at discharge, or the occurrence of other complications.

The fragile foundations of the extended fetuses-at-risk approach

BACKGROUND

Whether denominators for postnatal outcomes (ascertained after live birth) with a presumed prenatal origin should consist of fetuses or live births remains controversial. Proponents argue that the extended fetuses-at-risk (FAR) approach (a), provides a justification for medically indicated preterm delivery, (b), avoids paradoxical results, and (c), permits quantification of incidence of fetal-infant phenomena, such as "revealed" small for gestational age (SGA)-which, under FAR, rises with advancing gestation.

METHODS

This conceptual paper examines the validity of the above arguments.

RESULTS

As obstetricians induce babies early because of fetal (or maternal) compromise and despite the dangers posed by immaturity, there is no need to modify a paradigm that portrays preterm birth as a powerful risk factor. The FAR approach generally avoids "paradoxical" intersections because FAR rates of postnatal outcomes depend on the birth rate. However, this property, which causes rates of most postnatal outcomes to rise at term, can also lead to risk reversals and other misleading findings. The FAR formulation does not yield the incidence of postnatal conditions but, rather, the incidence of live birth (and survival to diagnosis) of babies with prevalent conditions (and, sometimes, future ones).

CONCLUSIONS

The proposed arguments do not provide adequate support for extending the FAR approach to postnatal outcomes. As only live births can contribute to the numerator of rates, the usefulness and interpretability of FAR measures in this setting are limited.