Do maternal and neonatal outcomes differ with single or twin pregnancies affected by hypertensive disorders? A systematic review and meta-analysis.
Qingqing Shen, Qingqing Huang
✦ AI-curated · Sources linked
In 30 seconds
This systematic review and meta-analysis compared maternal and neonatal outcomes in singleton and twin pregnancies complicated by hypertensive disorders of pregnancy, drawing on 13 comparative studies identified through searches up to 15 May 2025. In analyses of crude data, twin pregnancies had significantly higher risks of preterm birth and cesarean section; small-for-gestational-age birth was also more frequent overall, although this association was not seen in the preeclampsia subgroup. Twin pregnancies were linked to greater neonatal death risk, while several other neonatal outcomes did not differ.
Key findings
- Compared with singleton pregnancies affected by hypertensive disorders, twins had significantly higher risks of preterm birth and cesarean section in crude-data analyses.
- Small-for-gestational-age birth was more frequent in twins overall, but the difference was not observed in the preeclampsia subgroup.
- Twin pregnancies were associated with significantly greater risk of neonatal death.
- No differences were found in 5-min Apgar score <7, respiratory distress, or NICU admission.
Why it matters
These findings suggest that plurality may help frame expectations for maternal delivery outcomes and neonatal risk when hypertensive disorders complicate pregnancy. The absence of detected differences in several neonatal outcomes also provides useful context. However, the evidence is observational and the reported associations should not be interpreted as causal or as establishing that twin pregnancy itself explains the outcome differences.
What to keep in mind
The review notes that confounders were not adjusted for in the evidence, a major limitation. The preeclampsia subgroup finding for small-for-gestational-age birth is based on limited research and warrants caution.