Table 3.
Use of tocolytic agents in 2018, 2019, and 2020 among all deliveries and cases with threatened preterm labor.
| Year of childbirth | ||||||
|---|---|---|---|---|---|---|
| Before COVID-19 pandemic | During COVID-19 pandemic | |||||
| 2018 | 2019 | p-valuec | 2020 | p-valued | p-valuee | |
| Number of deliveries (n) | 5533 | 6257 | 5956 | |||
| Use of ritodrine for oral administrationa (n, %) | 1720 (31.1) | 1911 (30.5) | 0.523 | 1626 (27.3) | < 0.001 | < 0.001 |
| Use of ritodrine for intravenous administrationa (n, %) | 364 (6.6) | 424 (6.8) | 0.668 | 396 (6.7) | 0.880 | 0.778 |
| Number of threatened preterm labor cases (n) | 2507 | 2781 | 2458 | |||
| Use of ritodrine hydrochloride | ||||||
| For oral administrationb (n, %) | 1720 (68.6) | 1911 (68.7) | 0.932 | 1626 (66.2) | 0.065 | 0.048 |
| Dosage for oral administration (tablets per delivery) | 63.0 (28.0, 141.0) | 63.0 (28.0, 133.0) | 0.263 | 62.5 (21.0, 132.0) | 0.064 | 0.430 |
| For intravenous administrationb (n, %) | 364 (14.5) | 424 (15.3) | 0.459 | 396 (16.1) | 0.120 | 0.390 |
| Dosage for intravenous administration (ampoules per delivery) | 21.5 (6.5, 66.0) | 20.0 (6.0, 58.0) | 0.290 | 22.0 (6.0, 62.0) | 0.663 | 0.573 |
| Use of magnesium sulfateb (n, %) | 84 (3.4) | 83 (3.0) | 0.447 | 78 (3.2) | 0.725 | 0.693 |
| Dosage of magnesium sulfate (ampoules per delivery) | 8.0 (4.0, 32.0) | 7.0 (3.0, 31.0) | 0.787 | 8.0 (4.0, 37.0) | 0.507 | 0.283 |
| Threatened preterm labor treated in larger medical institutions (≥ 20 beds)b (n, %) | 1153 (46.0) | 1250 (45.0) | 0.447 | 1075 (43.7) | 0.110 | 0.378 |
Uses of medicines are described in number (a: % for the number of deliveries, b: % for the number of threatened preterm labor cases), and their dosages are described in median (25th percentile, 75th percentile).
P-values of Pearson’s chi-square test or Wilcoxon’s rank sum test c: between 2018 and 2019, d: between 2018 and 2020, and e: between 2019 and 2020 are shown. We used a P value of 0.0167 to indicate significance to correct for multiplicity.