Results
Between January 2016 and December 2020, a total of 12 095 women with a singleton pregnancy gave birth at term prior to the change in clinical practice and 28 162 gave birth after it was implemented. One third of women giving birth at Monash Health in both time periods were themselves born in South Asia. The characteristics of the women who gave birth in the two time periods are presented in Table 1. There was a total of 3506 south Asian born women in the period prior to and 8532 in the period after the change in practice.
The rates of stillbirth at term before and after the change in practice are presented in Table 2. Prior to the change in practice the rate of stillbirth at term for south Asian born women was 2.3 per 1000 births. This was 2.6-fold higher than the overall rate for all other women (0.9 per 1000 births) at the health service (p=0.06). After the change in practice there was a 64% reduction in rate of stillbirth (95%CI 87% to 2%; p=0.047) for south Asian born women after adjustment for potential confounders. The rate of stillbirth for south Asian born women after the change in practice reduced to a rate that was equivalent all other women giving birth at Monash Health.
The rates of stillbirth per on going week before and after the change in practice are presented in Figure 1. For south Asian born women prior to the change in practice the rates of stillbirth increased earlier and at a steeper rate for each advancing week of gestation when compared to all other women. After the change in practice, we observed a 45% reduction in the rate of stillbirth at 38 weeks, a 60% reduction at 39 weeks and there were no stillbirths that occurred at 40 weeks or beyond. The rates of stillbirth per on going week for all other women are also presented. Overall, the rates of stillbirth from 37-39 weeks remained the same across the whole study period and there was an observed 25% reduction in the rate of stillbirths at 40 and 41 weeks in the post period.
The rates of secondary outcomes before and after the change in practice and the impact of the practice change on the rates of induction of labour are presented in Table 3 and Figure 2. For south Asian born women, the rates of early neonatal death (3.1 per 1000 vs 1.3 per 1000; p=0.03) and SCN admission (16.5% vs 11.1%; p<0.001) decreased after the change in practice and there were no significant differences in admission to NICU, Apgar<7 at 5 minutes or baby birthweight. Similar to what was observed with stillbirth rates, the rate of NND for south born women following the change in practice became equivalent to all other women. Review of the timing of NNDs revealed that prior to the guideline NNDs were experienced following birth between 38- and 41-weeks’ gestation and following the change in practice the NNDs that occurred were all born below 40 weeks’ gestation. Prior to the change in practice the median gestation of birth for south Asian born women was 39+3(IQR 38+4 to 40+1) weeks and this reduced by 1 day in the period after the change in practice 39+2(38+3 to 40) weeks (p<0.001). There were no differences in the mode of birth following the change in practice. For comparison the rates for all other women who were not undergoing earlier monitoring are also presented.
The overall rates of induction of labour were significantly higher following the change in practice for both south Asian and all other women. The impact of the change in practice on trends in rates of induction of labour for South Asian born women compared to all other women are presented in Figure 2. South Asian born women initially (January 2016) had an absolute 3% higher rate of induction of labour (95% CI 0.3% to 4.8%; p=0.03) compared to all other women at the maternity service. For both south Asian and all other women, the rates of induction of labour increased in the period prior to the change in practice, however there was no difference in the slope of this increase between south Asian and all other women (-0.05%, 95% CI -0.3% to 0.2%; p=0.67). Immediately following the change in practice, the rates of induction in south Asian born women were 4.9% higher (95% CI 1.3% to 8.5%; p=0.008) than in all other women however there was no significant difference in the rate of change of induction rates per month after the change in practice in south Asian born women when compared to all other women (-0.1%, 95%CI-0.3% to 0.1%; p=0.41). Finally, in the period after the change in practice the rates of induction did not significantly change per month in south Asian born women (0.02%, 95% CI -0.08% to 0.1%) however all other women experienced a 0.17% increased rate of induction per month (95% CI 0.10% to 0.20%; p<0.001).