Objective To determine whether home cervical ripening is associated with acceptable safety margins compared to in-hospital cervical ripening during induction of labour. Design A prospective multicentre observational cohort study using routinely collected data. Setting Twenty-six UK maternity units; 18 offering only in-hospital cervical ripening and 8 offering both in-hospital and home cervical ripening. Population Women with singleton pregnancies, no previous caesarean section, at or beyond 37 weeks gestation having induction with details of cervical ripening method and location recorded. Methods Home cervical ripening using a balloon catheter was compared to in-hospital cervical ripening using prostaglandin. Multivariable logistic regression was performed for the primary outcome. Exposure: Cervical ripening at home using balloon catheter. Main outcome measures Primary outcome: neonatal unit admission within 48 hours of birth for 48 hours or more. Additional neonatal, maternal, labour progress and process outcomes were reported. Results Of 17,530 eligible women, 515 had balloon cervical ripening at home and 4332 had prostaglandin cervical ripening in a hospital that did not offer home cervical ripening. The primary outcome following home cervical ripening with balloon was not higher {16/515 (3.1%) vs 208/4332 (4.8%)}, but with substantial uncertainty on adjusted analysis consistent with a 64% lower risk through to an 81% higher risk. Conclusions Home cervical ripening using balloon catheter may be as safe for babies as using prostaglandin in hospital in low and moderate-risk groups, but further safety data are required.

Objective To estimate the shape and magnitude of associations between maternal Hb levels in the first and third trimesters of pregnancy, and pregnancy outcomes in a high-income setting. Design Prospective cohort studies Setting Two population based pregnancy cohorts from the UK Population The Avon Longitudinal Study of Parents and Children(ALSPAC) and Pregnancy Outcome Prediction Study(POPS). Methods We used multivariable logistic regression models to examine the relationship between Hb and pregnancy outcomes, adjusting for maternal age, ethnicity, BMI, smoking status and parity. Main Outcome Measures Preterm labour, low birth weight, small for gestational age(SGA), pre-eclampsia(PET), and gestational diabetes mellitus(GDM). Results There was no strong evidence of associations between a higher Hb (1g/dL) in the first trimester and preterm birth (1.07: 95% CI 0.96,1.21), low birth weight(1.09: 0.96, 1.24) and SGA (1.05; 0.96, 1.14). Higher Hb in the third trimester was associated with preterm birth (1.43:1.28,1.61), low birth weight(1.68: 1.48,1.90) and SGA (1.41:1.30, 1.53). Higher Hb in the first and third trimesters were associated with PET in ALSPAC(1st trimester- 1.38:1.07,1.76, 3rd trimester- 1.57: 1.28,1.94) but not in POPS(1st trimester- 1.10: 0.92, 1.30, 3rd trimester- 1.10: 0.92, 1.31). In ALSPAC(1st trimester- 1.37:0.96,1.95, 3rd trimester- 1.35:0.97,1.78) and POPS(1st trimester- 0.94:0.77, 1.17, 3rd trimester- 0.85: 0.69, 1.01), there were no associations with GDM. Conclusion Higher maternal Hb, in late pregnancy, may indicate a suboptimal increase in blood volume and therefore, women at risk of adverse pregnancy outcomes. Further research is required to investigate if this association is causal, and to identify underlying mechanisms.