Takeaway
- Caesarean birth in the second stage of term labour was associated with an increased risk of subsequent spontaneous preterm birth compared with vaginal birth.
- In contrast, early or first stage caesarean birth, but not second stage caesarean birth, was associated with an increased risk of subsequent medically indicated preterm birth.
Why this matters
- Findings warrant further research to confirm the association between second stage caesarean and early spontaneous preterm birth and confirm appropriate management strategies.
Study design
- This retrospective cohort study at 2 UK maternity units included 16,340 women with first 2 consecutive singleton births and the first birth at term using routinely collected clinical data.
- Funding: None.
Key results
- Emergency caesarean vs vaginal birth in the second stage of labour was associated with an increased risk of:
- subsequent spontaneous preterm birth at <37 weeks gestation (4.5% full dilatation caesarean vs 2.3% vaginal birth; adjusted OR [aOR], 3.29; 95% CI, 2.02-5.13); and
- early spontaneous preterm birth at <34 weeks gestation (2% full dilatation caesarean vs 0.5% vaginal birth; aOR, 7.55; 95% CI, 3.42-15.41; P<.001 for both).
- Compared with vaginal birth, the risk of medically indicated preterm birth at <37 weeks gestation was increased with:
- elective caesarean (aOR, 2.30; 95% CI, 1.19-4.15; P=.009);
- emergency caesarean <4 cm (aOR, 4.68; 95% CI, 2.98-7.24; P<.001); and
- emergency caesarean 4-9 cm (aOR, 2.43; 95% CI, 1.43-4.00; P=.001).
- Second stage caesarean was not significantly associated with an increased risk of medically indicated preterm birth at <37 weeks gestation (emergency caesarean 10 cm: aOR, 1.76; 95% CI, 0.61-4.05; P=.234).
- Emergency caesarean vs vaginal birth in the first stage of labour was associated with an increased risk of early medically indicated preterm birth at <34 weeks gestation (aOR, 4.16; 95% CI, 1.55-10.09; P=.002).
Limitations
- Retrospective design.
This clinical summary originally appeared on Univadis, part of the Medscape Professional Network.
