Table 2.
Interrupted time series analyses, with Prais-Winsten regression model, of maternal and perinatal health indicators during COVID-19 pandemic: immediate and progressive impact of the COVID-19 vaccination for pregnant women.
| Period |
COVID-19 pandemic, before pregnant women vaccination (March 2020–June 2021) |
COVID-19 pandemic, from the start of COVID-19 vaccination for pregnant women (July 2021–December 2022) |
Durbin–Watson statisticc | ||||
|---|---|---|---|---|---|---|---|
| Maternal and perinatal health indicators | Trend |
Immediate impacta |
Progressive impactb |
||||
| Monthly percent change (95% CI) | Interpretation | Percent change (95% CI) | Interpretation | Monthly percent change (95% CI) | Interpretation | ||
| Maternal mortality ratio (per 100,000 live births) | 5.86 (2.27, 9.57)∗∗ | Increase | −34.10 (−54.10, −5.39)∗ | Decrease | −9.43 (−13.81, −4.72)∗∗∗ | Decrease | 1.82 |
| Acute respiratory distress during pregnancy (per 100,000 live births) | 5.95 (−0.66, 13.00) | Stationary | −38.16 (−70.50, 29.64) | No change | −13.19 (−20.65, −5.03)∗∗ | Decrease | 1.51 |
| Perinatal mortality rate (per 1000 births) | −0.18 (−0.33, −0.69) | Stationary | −0.04 (−5.94, 6.24) | No change | −0.29 (−0.98, 0.41) | Stationary | 1.93 |
| Facility births rate (%) | −0.01 (−0.02, 0.00) | Stationary | −0.07 (−0.18, 0.04) | No change | 0.03 (0.01, 0.04)∗∗∗ | Increase | 1.64 |
| Cesarean section rate (%) | 0.03 (−0.04, 0.10) | Stationary | −1.87 (−2.72, −1.01)∗∗∗ | Decrease | 0.25 (0.16, 0.34)∗∗∗ | Increase | 2.06 |
| Low birth weight rate (%) | 0.34 (0.10, 0.58)∗∗ | Increase | 0.66 (−2.41, 3.83) | No change | 0.09 (−0.22, 0.40) | Stationary | 1.88 |
| Preterm birth rate (%) | 0.07 (−0.27, 0.42) | Stationary | −0.21 (−4.57, 4.35) | No change | 0.24 (−0.20, 0.68) | Stationary | 2.16 |
| Apgar score <7 at the 1st minute rate (%) | 0.08 (−0.07, 0.24) | Stationary | 0.30 (−1.52, 2.15) | No change | −0.01 (−0.21, 0.20) | Stationary | 1.72 |
| Apgar score <7 at the 5th minute rate (%) | 0.28 (0.004, 0.56)∗ | Increase | −1.27 (−4.67, 2.25) | No change | −0.19 (−0.55, 0.18) | Stationary | 1.93 |
95% CI, 95% Confidence Interval.
∗p < 0.05; ∗∗p < 0.01; ∗∗∗p < 0.001.
Results highlighted in bold presented a p-value lower than 0.05.
“No change” means that there was no statistical evidence of a level change following the segmentation of the series, compared to the preceding segment.
Brazil, March 2020–December 2022.
Immediate impact represents change in level following the segmentation of the time series.
Progressive impact indicates change in slope following the start of COVID-19 vaccination for pregnant women without comorbidities.
Durbin Watson statistics after applying the Prais-Winsten model to correct for serial autocorrelation.
Sources: Brazilian Ministry of Health. Live Birth Information System (SINASC), Mortality Information System (SIM), Acute Respiratory Syndrome Surveillance System (SIVEP). Data extracted on 07/14/2023. Data for 2022 are preliminary, subject to change.