Late preterm neonatal morbidity in hypertensive versus normotensive women

Consequences of early-onset preeclampsia on neonatal morbidity and mortality

Preterm birth is the leading cause of perinatal morbidity and mortality in developed countries. Common reasons for indicated preterm births include pre-eclampsia. The increase in incidences of morbidity and mortality observed in neonates resulting from pregnancies complicated by preeclampsia is also due to alterations in angiogenic and pro-inflammatory factors that directly affect the neonatal health. This review was prepared with the aim of gathering the information available at PubMed/MEDLINE, in the years from 2011 to 2021, on the consequences of neonatal morbidity and mortality of early-onset preeclampsia. There is great controversy in the literature and paucity of studies. Early onset pre-eclampsia has been linked to fetal growth restriction (FGR). Most studies support its association with respiratory distress syndrome (RDS). Most studies point to an association between preeclampsia and bronchopulmonary dysplasia (BPD), with the highest risk in FGR. The association between preeclampsia, patent ductus arteriosus (PDA) and sepsis is not supported by the literature. The association to necrotizing enterocolitis (NEC) is controversial. The risk of spontaneous intestinal perforation (SIP) seems to be increased with preeclampsia. The association between intraventricular hemorrhage (IVH) and preeclampsia is controversial, however, preeclampsia seems to have a protective effect on periventricular leukomalacia (PVL). Most of the evidence points to the non-association between preeclampsia and retinopathy of prematurity (ROP). Hematological changes such as neutropenia, thrombocytopenia and increased nucleated red blood cell counts have been shown to be associated with preeclampsia. The evidence is still quite controversial regarding mortality. The early installation of preeclampsia will have direct consequences on neonatal morbidity. Gestational age at preterm birth is the main risk factor on neonatal morbidity. Obstetricians should aim to prolong the pregnancies complicated by early-onset severe preeclampsia as far as maternal conditions allow. This policy may contribute to improve the neonatal outcomes.

Antiplatelet agents for preventing pre-eclampsia and its complications

BACKGROUND

Pre-eclampsia is associated with deficient intravascular production of prostacyclin, a vasodilator, and excessive production of thromboxane, a vasoconstrictor and stimulant of platelet aggregation. These observations led to the hypotheses that antiplatelet agents, low-dose aspirin in particular, might prevent or delay development of pre-eclampsia.

OBJECTIVES

To assess the effectiveness and safety of antiplatelet agents, such as aspirin and dipyridamole, when given to women at risk of developing pre-eclampsia.

SEARCH METHODS

For this update, we searched Cochrane Pregnancy and Childbirth's Trials Register, ClinicalTrials.gov, the WHO International Clinical Trials Registry Platform (ICTRP) (30 March 2018), and reference lists of retrieved studies. We updated the search in September 2019 and added the results to the awaiting classification section of the review.

SELECTION CRITERIA

All randomised trials comparing antiplatelet agents with either placebo or no antiplatelet agent were included. Studies only published in abstract format were eligible for inclusion if sufficient information was available. We would have included cluster-randomised trials in the analyses along with individually-randomised trials, if any had been identified in our search strategy. Quasi-random studies were excluded. Participants were pregnant women at risk of developing pre-eclampsia. Interventions were administration of an antiplatelet agent (such as low-dose aspirin or dipyridamole), comparisons were either placebo or no antiplatelet.

DATA COLLECTION AND ANALYSIS

Two review authors assessed trials for inclusion and extracted data independently. For binary outcomes, we calculated risk ratio (RR) and its 95% confidence interval (CI), on an intention-to-treat basis. For this update we incorporated individual participant data (IPD) from trials with this available, alongside aggregate data (AD) from trials where it was not, in order to enable reliable subgroup analyses and inclusion of two key new outcomes. We assessed risk of bias for included studies and created a 'Summary of findings' table using GRADE.

MAIN RESULTS

Seventy-seven trials (40,249 women, and their babies) were included, although three trials (relating to 233 women) did not contribute data to the meta-analysis. Nine of the trials contributing data were large (> 1000 women recruited), accounting for 80% of women recruited. Although the trials took place in a wide range of countries, all of the nine large trials involved only women in high-income and/or upper middle-income countries. IPD were available for 36 trials (34,514 women), including all but one of the large trials. Low-dose aspirin alone was the intervention in all the large trials, and most trials overall. Dose in the large trials was 50 mg (1 trial, 1106 women), 60 mg (5 trials, 22,322 women), 75mg (1 trial, 3697 women) 100 mg (1 trial, 3294 women) and 150 mg (1 trial, 1776 women). Most studies were either low risk of bias or unclear risk of bias; and the large trials were all low risk of bas. Antiplatelet agents versus placebo/no treatment The use of antiplatelet agents reduced the risk of proteinuric pre-eclampsia by 18% (36,716 women, 60 trials, RR 0.82, 95% CI 0.77 to 0.88; high-quality evidence), number needed to treat for one women to benefit (NNTB) 61 (95% CI 45 to 92). There was a small (9%) reduction in the RR for preterm birth <37 weeks (35,212 women, 47 trials; RR 0.91, 95% CI 0.87 to 0.95, high-quality evidence), NNTB 61 (95% CI 42 to 114), and a 14% reduction infetal deaths, neonatal deaths or death before hospital discharge (35,391 babies, 52 trials; RR 0.85, 95% CI 0.76 to 0.95; high-quality evidence), NNTB 197 (95% CI 115 to 681). Antiplatelet agents slightly reduced the risk of small-for-gestational age babies (35,761 babies, 50 trials; RR 0.84, 95% CI 0.76 to 0.92; high-quality evidence), NNTB 146 (95% CI 90 to 386), and pregnancies with serious adverse outcome (a composite outcome including maternal death, baby death, pre-eclampsia, small-for-gestational age, and preterm birth) (RR 0.90, 95% CI 0.85 to 0.96; 17,382 women; 13 trials, high-quality evidence), NNTB 54 (95% CI 34 to 132). Antiplatelet agents probably slightly increase postpartum haemorrhage > 500 mL (23,769 women, 19 trials; RR 1.06, 95% CI 1.00 to 1.12; moderate-quality evidence due to clinical heterogeneity), and they probably marginally increase the risk of placental abruption, although for this outcome the evidence was downgraded due to a wide confidence interval including the possibility of no effect (30,775 women; 29 trials; RR 1.21, 95% CI 0.95 to 1.54; moderate-quality evidence). Data from two large trials which assessed children at aged 18 months (including results from over 5000 children), did not identify clear differences in development between the two groups.

AUTHORS' CONCLUSIONS

Administering low-dose aspirin to pregnant women led to small-to-moderate benefits, including reductions in pre-eclampsia (16 fewer per 1000 women treated), preterm birth (16 fewer per 1000 treated), the baby being born small-for-gestational age (seven fewer per 1000 treated) and fetal or neonatal death (five fewer per 1000 treated). Overall, administering antiplatelet agents to 1000 women led to 20 fewer pregnancies with serious adverse outcomes. The quality of evidence for all these outcomes was high. Aspirin probably slightly increased the risk of postpartum haemorrhage of more than 500 mL, however, the quality of evidence for this outcome was downgraded to moderate, due to concerns of clinical heterogeneity in measurements of blood loss. Antiplatelet agents probably marginally increase placental abruption, but the quality of the evidence was downgraded to moderate due to low event numbers and thus wide 95% CI. Overall, antiplatelet agents improved outcomes, and at these doses appear to be safe. Identifying women who are most likely to respond to low-dose aspirin would improve targeting of treatment. As almost all the women in this review were recruited to the trials after 12 weeks' gestation, it is unclear whether starting treatment before 12 weeks' would have additional benefits without any increase in adverse effects. While there was some indication that higher doses of aspirin would be more effective, further studies would be warranted to examine this.

Pregnancy induced hypertension and outcomes in early and moderate preterm infants

OBJECTIVE

To identify the effect of pregnancy induced hypertension on neonatal outcomes in early and moderate preterm infants of gestational age less than 34 weeks.

STUDY DESIGN

Prospectively collected data in 773 premature deliveries less than 34 weeks from 10 centers in China between July 2014 and July 2016 were analyzed in this cohort study. Univariate and Multivariate regression analyses were conducted to exam the effect of pregnancy induced hypertension on neonatal outcomes, including mortality to discharge, intrauterine growth restriction, severe brain injury, neonatal respiratory distress syndrome, bronchopulmonary dysplasia, necrotizing enterocolitis, early onset of sepsis and retinopathy of prematurity.

RESULTS

The incidence of PIH in this cohort was 18.4%. Women with PIH tended to have a higher cesarean delivery rate (78.2% vs 40.9%, P < 0.001). More tocolytics and magnesium sulfate were used in PIH women (72.5% vs 48.7%, P < 0.001; 59.2% vs 34.7%, P < 0.001). Mean birth weight was lower in infants of PIH mothers than infants of non-PIH mothers (1522.1 ± 348.8 g vs 1683.4 ± 345.3, P < 0.001). In multivariate regression models, PIH was associated with increased risk of IUGR (OR 8.402; 95% CI 4.350-16.227) and lower odds of NRDS (OR 0.526; 95% CI 0.332-0.853).

CONCLUSION

Preterm infants less than 34 weeks born to PIH women had a higher risk of intrauterine growth restriction and lower birth weight. PIH warrants more intensive interventions to prevent relevant infant morbidities.