Planned early birth reduces maternal morbidity and stillbirth risk in late preterm hypertensive disorders of pregnancy

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The Cochrane database of systematic reviews Published May 21, 2026 Medically reviewed May 21, 2026 Study authors: Beardmore-Gray Alice, Rohwer Christa, Fernandez Turienzo Cristina, Cluver Catherine A PubMed ↗ DOI ↗ By Dr. Sofia Müller, MD · Lifespan & Whole-Person Care

Key Takeaway

Consider planned early birth for maternal morbidity reduction in late preterm hypertensive disorders.

This Cochrane review is a meta-analysis that synthesizes evidence from six studies conducted in high-income countries and one study in low- and middle-income countries. The analysis focused on pregnant women diagnosed with hypertensive disorders of pregnancy at 34 weeks gestation or later. The total sample size across all included studies was 3491 women. The primary comparison was between planned early birth, achieved through induction of labour or caesarean section, and expectant management. The review aimed to determine the effects of timing delivery on maternal and perinatal outcomes in this specific population.

The primary outcome assessed was a composite of maternal mortality and morbidity. Analysis of this outcome showed a reduced risk for the planned early birth group. The relative risk was 0.54 with a 95% confidence interval of 0.37 to 0.77. This finding suggests a significant protective effect against severe maternal complications when delivery is planned earlier rather than continuing expectant management. The confidence interval does not cross the null value, indicating a statistically significant reduction in this composite endpoint.

Secondary outcomes included the risk of caesarean section. The data demonstrated no increased risk for the early birth group compared to expectant management. The relative risk was 0.94 with a 95% confidence interval of 0.83 to 1.06. This indicates that planning for early delivery does not inherently increase the likelihood of requiring a caesarean section in this context. Other secondary outcomes showed mixed results. There was a large reduction in the risk of stillbirth, with a relative risk of 0.25 and a 95% confidence interval of 0.07 to 0.87.

Regarding neonatal outcomes, the risk of neonatal unit admission showed little to no difference between groups. The relative risk was 1.11 with a 95% confidence interval of 0.90 to 1.37. Maternal death showed little to no difference with a relative risk of 0.33 and a 95% confidence interval of 0.05 to 2.10. Neonatal death also showed little to no difference with a relative risk of 1.40 and a 95% confidence interval of 0.45 to 4.35. The composite outcome of perinatal mortality and morbidity showed a very uncertain effect. The relative risk was 1.06 with a 95% confidence interval of 0.75 to 1.51.

Safety and tolerability data were not reported in the source material. Serious adverse events, discontinuations, and specific tolerability metrics were not provided in the input data. The review noted high variation between trials for the composite perinatal mortality and morbidity outcome. Imprecision was observed where confidence intervals crossed the line of both appreciable benefit and harm for some analyses. Additionally, there was a low number of events in some specific analyses, which limits the precision of the estimates for those endpoints.

The certainty of the evidence varied by outcome. High-certainty evidence supported the findings for maternal mortality and morbidity and caesarean section. Moderate-certainty evidence supported the findings for stillbirth and neonatal unit admission. Low-certainty evidence supported the findings for maternal death and neonatal death. Very low-certainty evidence supported the findings for the composite perinatal mortality and morbidity. These certainty ratings reflect the limitations in the underlying data and the heterogeneity of the included studies.

Clinical implications suggest that the timing of delivery should take into account the woman's preferences, the type of hypertensive disorder, and the presence or absence of severe features. While the reduction in maternal morbidity and stillbirth is compelling, the uncertainty regarding the composite perinatal outcome and the lack of data on longer-term infant outcomes require caution. The review does not distinguish between association and causation explicitly, and results are presented as risk reduction or increase. Practitioners should interpret these findings within the context of individual patient circumstances and the specific limitations of the available evidence.

Questions remain unanswered regarding longer-term infant outcomes and longer-term maternal cardiovascular health. The input data explicitly advises against overstating conclusions about these specific areas. The review was not funded by a dedicated funding source, and no conflicts of interest were reported. The analysis covers a broad range of hypertensive disorders but does not provide granular data for every specific subtype. Clinicians must balance the clear benefit in maternal morbidity and stillbirth against the uncertainty in other perinatal metrics when making delivery timing decisions.

Study Details

Study typeMeta analysis

Sample sizen = 3,491

EvidenceLevel 1

Follow-up7.9 mo

PublishedMay 2026

PMID42161381

View Original Abstract ↓

RATIONALE: Hypertensive disorders in pregnancy are significant contributors to maternal and perinatal morbidity and mortality. They include chronic hypertension, gestational hypertension and pre-eclampsia. Definitive management of these disorders is planned early birth. The alternative is expectant management with close monitoring, if severe complications are not present. There are benefits and risks associated with both policies, so it is important to establish the safest option. OBJECTIVES: To assess the benefits and risks of planned early birth versus expectant management in pregnant women with hypertensive disorders, from 34 weeks' gestation onwards. SEARCH METHODS: An Information Specialist within the Cochrane Central Executive Team searched CENTRAL, MEDLINE, Embase, CINAHL, ClinicalTrials.gov and WHO ICTRP. The searches were run from 1 January 2016 to 16 January 2026 with no language restrictions. Reference lists of retrieved studies were also searched. ELIGIBILITY CRITERIA: We included randomised controlled trials comparing planned early birth (by induction of labour or by caesarean section) with expectant management for women with hypertensive disorders from 34 weeks' gestation. Cluster-randomised trials would have been eligible for inclusion in this review, but we found none. Studies using a quasi-randomised design were not eligible for inclusion in this review. Studies using a cross-over design were not eligible for inclusion, because they are not a suitable study design for investigating hypertensive disorders in pregnancy. OUTCOMES: The prespecified critical outcomes (based upon a core outcome set agreed via Delphi consensus) were (1) a composite outcome of maternal mortality and morbidity; (2) a composite outcome of perinatal mortality and morbidity; (3) maternal death; (4) fetal death; (5) neonatal death. The prespecified important maternal outcomes were: caesarean section, maternal admission to a high dependency unit, eclampsia, pulmonary oedema, severe renal impairment, and HELLP (haemolysis, elevated liver enzymes, low platelets) syndrome. The prespecified important perinatal outcome was neonatal unit admission. Additional maternal and perinatal outcomes were also analysed in accordance with the review protocol, including maternal quality of life measures and health resource use. RISK OF BIAS: Two review authors independently assessed risk of bias using the Cochrane Risk of Bias 2 (RoB 2) tool. The Cochrane trustworthiness screening tool was applied to all eligible studies at full-text review stage. SYNTHESIS METHODS: Two review authors independently assessed eligibility and risk of bias. Two review authors independently extracted data using a prespecified data extraction form. Data were checked for accuracy. Statistical analysis was carried out in RevMan using a random-effects meta-analysis. We assessed the certainty of evidence using GRADE. INCLUDED STUDIES: We included six studies involving 3491 women. All six studies were randomised controlled trials evaluating planned early birth compared to expectant management. Planned early birth was evaluated at between 34 and 37 weeks in four studies, between 36 and 38 weeks in one study and between 36 and 41 weeks in one study. One study took place in low- and middle-income countries, whilst five took place in high-income countries. Three studies included only women with pre-eclampsia, two studies included women with a mixture of hypertensive disorders in pregnancy and one study included only women with chronic hypertension. SYNTHESIS OF RESULTS: Planned early birth reduces the risk of maternal mortality and morbidity compared to expectant management (RR 0.54, 95% CI 0.37 to 0.77; I² = 0%; 6 studies, 3491 participants; high-certainty evidence). There was no increased risk of caesarean section associated with planned early birth (RR 0.94, 95% CI 0.83 to 1.06; I² = 25%; 6 studies, 3539 participants; high-certainty evidence). Planned early birth likely results in a large reduction in the risk of stillbirth (fetal death) (RR 0.25, 95% CI 0.07 to 0.87; I² not applicable; 5 studies, 3407 participants; moderate-certainty evidence), but probably results in little to no difference in rates of neonatal unit admission (RR 1.11, 95% CI 0.90 to 1.37; I² = 41%; 6 studies, 3560 participants; moderate-certainty evidence). Planned early birth may result in little to no difference in maternal death (RR 0.33, 95% CI 0.05 to 2.10; I² = 0%; 6 studies, 3491 participants; low-certainty evidence) or neonatal death (RR 1.40, 95% CI 0.45 to 4.35; I² not applicable; 5 studies, 3407 participants; low-certainty evidence). The evidence is very uncertain about the effect of planned early birth on composite perinatal mortality and morbidity due to high variation between the trials (RR 1.06, 95% CI 0.75 to 1.51; I² = 83%; 6 studies, 3576 participants; very low-certainty evidence). Five of the six trials included in this analysis were at low risk of bias. We graded the evidence as high, moderate, low, or very low certainty based upon GRADE criteria. Where we downgraded the evidence, it was typically due to higher levels of heterogeneity or due to imprecision, whereby the confidence interval crossed the line of both appreciable benefit and harm or the number of events was low. AUTHORS' CONCLUSIONS: For women with hypertensive disorders of pregnancy beyond 34 weeks' gestation, planned early birth is associated with a lower risk of maternal complications, and probably a reduced risk of fetal death (stillbirth), with no increased risk of caesarean section and probably no clear differences in the rate of neonatal unit admission or short-term neonatal morbidity. It is important that the timing of delivery takes into account the woman's preferences, the type of hypertensive disorder and the presence or absence of severe features. Further information is needed to establish the longer-term infant outcomes associated with late preterm birth and longer-term maternal cardiovascular health. FUNDING: This Cochrane review had no dedicated funding. REGISTRATION: The original review and review protocol can be accessed via the following links. Protocol (2011): DOI: 10.1002/14651858.CD009273 Original review (2017): DOI: 10.1002/14651858.CD009273.pub2.