Trends in obstetric interventions, level of care and low
Apgar scores in subgroups
Table 3 shows trends in the five prespecified obstetric
interventions and the incidences of a low Apgar score (<7 and
<4) in these subgroups. The incidence of induced labour, use
of epidural analgesia and planned caesarean section increased
significantly between 2010 and 2019 (from 19.8% to 23.9%
(p <0.0001), from 15.2% to 20.5%
(p< 0.0001), and from 6.5% to 7.2%
(p <0.0001), respectively). Epidural analgesia showed
the strongest increase, with a significant relative increase of 34.8%
between 2010 and 2019 (from 15.2% in 2010 to 20.5% in 2019). In total,
8.4% of all infants were born by instrumental vaginal delivery and
8.1% by emergency caesarean section. Incidences of both interventions
showed a decreasing trend; instrumental vaginal deliveries decreased
from 10.2% to 7.1% (-31.4% relative difference,p <0.0001), and emergency caesarean sections from 9.0%
in 2010 to 7.9% in 2019 (-10.8% relative difference,p <0.0001).
Within all five obstetric intervention subgroups, a significant increase
in infants with an Apgar score <7 was observed. The highest
increase in low Apgar score <7 was observed in the subgroups
of instrumental vaginal delivery (relative increase of 52.4%, with
absolute percentages increasing from 2.1% in 2010 to 3.2% in 2019
(p <0.0001)), and emergency caesarean section (relative
increase of 63.3%, with absolute percentages increasing from 3.0% in
2010 to 4.9% in 2010 (p <0.0001)).
For the Apgar score <4, a significant trend was only observed
in the subgroups of instrumental vaginal delivery and emergency
caesarean section. In the subgroup of instrumental vaginal delivery, the
proportion of infants with Apgar score <4 increased with 32%
(from an absolute percentage of 0.24% in 2010 to 0.32% in 2019,p <0.001). For the subgroup of emergency caesarean
section, the relative increase in low Apgar score <4 was 30%
(from an absolute percentage of 0.63 in 2010 to 0.82 in 2019,p <0.0001).
Table 4 shows the results of the analysis performed for level
of care. Overall, 28.7% of infants was born in primary care and 71.3%
in secondary care. As expected, the risk of a low Apgar score
<7 and <4 was higher for infants born in secondary
care compared to primary care. Both in primary and secondary care there
was a significant increase in infants with a low Apgar score
<7, but the highest increase was observed in secondary care.
Over time, the Apgar score <4 remained stable in primary care.
In secondary care, the proportion of infants with Apgar score
<4 increased significantly (from 0.22% to 0.26%, with a
relative difference of 18.2%) in subgroup with onset of birth in
secondary care, and from 0.22% to 0.25% (significant relative increase
of 18%) in subgroup with delivery in secondary care).
In the multivariate analysis, where we controlled for the co-factors in
separate models, still the trend in the low 5-minute Apgar <7
(1.04, 95% CI 1.04 to 1.05) and Apgar <4 (1.03, 95% CI 1.02
to 1.03) was significantly increased (Supplement Table 3).