Fig 1.
Flowchart: How we derived the dataset for analysis.
Table 1.
Numbers of singleton births in NHS maternity units by onset of labour, mode of birth, and gestational age group, 2005–2014.
Fig 2.
Mean number of singleton births in NHS maternity units per hour over the week, England 2005–2014.
“All births”: All singleton births in NHS maternity units in England linked in this study, 2005–2014: N = 5,999,732 (missing times: 54,804); “Study”: Singleton births included in study: n = 5,048,269 (missing times: 45,346).
Fig 3.
Average number of term births per hour by type of day: Spontaneous onset of labour.
Fig 4.
Average number of term births per hour by type of day: Induced births.
Fig 5.
Average number of term births per hour by type of day: Caesarean births without prior onset of labour.
Fig 6.
Average number of term births per hour by type of day: Spontaneous onset of labour (larger scale).
Fig 7.
Average number of term births per hour by type of day: Induced births (larger scale).
Table 2.
Adjusted rate ratios for frequency of term births by day of the week, compared to the overall average, by onset of labour and mode of birth (99% confidence intervals in brackets).
Fig 8.
Rate ratios and confidence intervals for type of day differences by gestational age: Spontaneous onset and birth.
Vertical axes show rate ratios relative to the overall average for each gestational age group within each figure. Error bars show 99% confidence intervals. Likelihood Ratio Test of H0: Type of day differences do not differ between term, pre-term and post-term births.
Fig 9.
Rate ratios and confidence intervals for type of day differences by gestational age: Spontaneous onset, emergency caesarean.
Vertical axes show rate ratios relative to the overall average for each gestational age group within each figure. Error bars show 99% confidence intervals. Likelihood Ratio Test of H0: Type of day differences do not differ between term, pre-term and post-term births.
Fig 10.
Rate ratios and confidence intervals for type of day differences by gestational age: Spontaneous onset, instrumental birth.
Vertical axes show rate ratios relative to the overall average for each gestational age group within each figure. Error bars show 99% confidence intervals. Likelihood Ratio Test of H0: Type of day differences do not differ between term, pre-term and post-term births.
Fig 11.
Rate ratios and confidence intervals for type of day differences by gestational age: Induced onset, spontaneous birth.
Vertical axes show rate ratios relative to the overall average for each gestational age group within each figure. Error bars show 99% confidence intervals. Likelihood Ratio Test of H0: Type of day differences do not differ between term, pre-term and post-term births.
Fig 12.
Rate ratios and confidence intervals for type of day differences by gestational age: Induced onset, emergency caesarean.
Vertical axes show rate ratios relative to the overall average for each gestational age group within each figure. Error bars show 99% confidence intervals. Likelihood Ratio Test of H0: Type of day differences do not differ between term, pre-term and post-term births.
Fig 13.
Rate ratios and confidence intervals for type of day differences by gestational age: Induced onset, instrumental birth.
Vertical axes show rate ratios relative to the overall average for each gestational age group within each figure. Error bars show 99% confidence intervals. Likelihood Ratio Test of H0: Type of day differences do not differ between term, pre-term and post-term births.
Fig 14.
Rate ratios and confidence intervals for type of day differences by gestational age: Elective caesarean.
Vertical axes show rate ratios relative to the overall average for each gestational age group within each figure. Error bars show 99% confidence intervals. Likelihood Ratio Test of H0: Type of day differences do not differ between term, pre-term and post-term births.
Fig 15.
Rate ratios and confidence intervals for type of day differences by gestational age: Emergency caesarean, no labour.
Vertical axes show rate ratios relative to the overall average for each gestational age group within each figure. Error bars show 99% confidence intervals. Likelihood Ratio Test of H0: Type of day differences do not differ between term, pre-term and post-term births.