There were 43577 deliveries in Harvard University Partners Healthcare Systems (PARTNERS) between January 1, 2016 and December 31, 2018, including 29,943 vaginal deliveries and 13,634 cesarean deliveries, the rate of cesarean delivery was 31.3%. There were 7109 multiparous women, who planned for vaginal delivery and encounter the labor process, 76.3% with epidural anesthesia, 27.8% with oxytocin (Table 1). The duration of first stage was 6.2(3.6–10.0) hours in multiparous women, the second stage was 0.3(0.2–0.7) hours, the total stage was 6.9(4.1–10.7) hours. The rate of overall adverse outcomes was 23.6%, the rate of maternal adverse outcomes were 9.4%, the rate of neonatal adverse outcomes were 17.1%, others adverse outcomes were showed in Table 2.
Table 1
Demographics and obstetrics characteristics of multiparous women (n = 7109).
| Median/n | IQR/% |
Duration of labor stage | | |
First stage (hour) * | 6.2 | 3.6–10.0 |
6 h | 3398 | 47.8 |
6-11.9 h | 2512 | 35.3 |
12-17.9 h | 820 | 11.5 |
18-23.9 h | 228 | 3.2 |
≥ 24 h | 151 | 2.1 |
Second stage (hour) * | 0.3 | 0.2–0.7 |
< 1 h | 5791 | 81.5 |
1-1.9 h | 776 | 10.9 |
2-2.9 h | 278 | 3.9 |
3-3.9 h | 129 | 1.8 |
≥ 4 h | 135 | 1.9 |
Total stage (hour) * | 6.9 | 4.1–10.7 |
< 12 h | 5717 | 80.4 |
12-23.9 h | 1208 | 17.0 |
≥ 24 h | 184 | 2.6 |
Gestational age(weeks) * | 39.6 | 39.0-40.3 |
Maternal age(years) * | 33.0 | 30.0–36.0 |
Maternal Height (cm) * | 162.6 | 160.0-167.6 |
Gestational weight gain(kg) * | 14.0 | 10.0–17.0 |
Maternal BMI(kg/m2) * | 29.4 | 26.6–32.6 |
Gravidity* | 3.0 | 2.0–4.0 |
Parity* | 2.0 | 2.0–3.0 |
Baby weight (g) * | 3459 | 3175–3750 |
Baby height (cm) * | 50.8 | 48.3–52.1 |
Ethnicity | | |
Non-Hispanic White | 4671 | 65.7 |
Non-Hispanic Black | 558 | 7.9 |
Hispanic | 273 | 3.8 |
Asian or Pacific Islanders | 737 | 10.4 |
Other or Unknown | 870 | 12.2 |
Epidural Anesthesia | 5423 | 76.3 |
Induction | 1647 | 23.2 |
Oxytocin | 1975 | 27.8 |
Data presented as n (%) or *median (interquartile range, non-normal distribution). |
Table 2
Adverse delivery outcomes of multiparous women.
| n | % |
Overall outcomes | 1677 | 23.6 |
Maternal outcomes | 671 | 9.4 |
Referral cesarean delivery | 98 | 1.4 |
Instrumental delivery | 207 | 2.9 |
Postpartum hemorrhage | 155 | 2.2 |
Lacerations | 78 | 1.1 |
Length of stay ≥ 90%th | 332 | 4.7 |
Neonatal outcomes | 1213 | 17.1 |
NICU | 411 | 5.8 |
Shoulder dystocia | 185 | 2.6 |
Apgar ≤ 7(5 min) | 89 | 1.3 |
Neonatal resuscitation | 790 | 11.1 |
Assisted ventilation | 181 | 2.5 |
Overall outcomes were including maternal and neonatal adverse outcoms |
The first stage of labor was stratified to < 6 h, 6-11.9 h, 12-17.9 h, 18-23.9 h, ≥ 24 h. With the increase of first stage duration, the rate of overall adverse outcomes was 21%, 23.4%, 28.8%, 35.5%, 38.4%, increased significantly (X2 = 57.64, P0.001). The rate of maternal adverse outcomes was 7.2%, 8.8%, 13.8%, 20.2%, 29.8%, increased significantly (X2 = 121.38, P0.001); The rate of neonatal adverse outcomes was 16.0%, 17.3%, 19.3%, 21.5%, 18.5%, increased significantly (X2 = 7.75, P = 0.005). There were significant differences in incidence of referral cesarean delivery, instrumental delivery, length of stay ≥ 90%th, shoulder dystocia, Apgar ≤ 7(5 min), neonatal resuscitation, assisted ventilation in different duration of the first stage (Table 3, Fig. 2). In order to analysis the effect of duration on adverse outcomes, with < 6 h as the reference, multivariable logistic regression showed ARR(95%CI) of overall adverse outcomes were 1.10(0.92,1.31), 1.33(1.04,1.70), 1.80(1.21,2.68), 2.57(1.60,4.15) in subgroups of 6-11.9 h, 12-17.9 h, 18-23.9 h, ≥ 24h;ARR(95%CI) of maternal adverse outcomes were 1.31(1.01,1.71), 2.42(1.74,3.37), 3.15(1.92,5.18), 5.52(3.19,9.58) in subgroups; ARR(95%CI) of neonatal adverse outcomes were 1.04(0.85,1.26), 0.95(0.71,1.27), 1.28(0.81,2.02), 1.27(0.71,2.25). The risk of referral cesarean delivery and length of stay ≥ 90%th increased with longer first stage. It was showed in Table 4, Fig. 3. In order to understand the different cutoff values on the risk of adverse outcomes, the first stage < 6 h and ≥ 6 h were compared, ARR(95%CI) was 1.23(1.05, 1.43); if the cutoff value were 12 h, 18 h, 24 h, ARR(95%CI) of overall adverse outcomes were 1.48(1.22, 1.80), 1.92(1.41, 2.59), 2.33(1.45, 3.72); ARR(95%CI) of maternal adverse outcomes were 1.76(1.40, 2.22), 2.55(1.98, 3.28), 3.61(2.13, 4.40), 4.05(2.39, 6.86), ARR(95%CI) of neonatal adverse outcomes were 1.04(0.87,1.24), 1.03(0.82,1.30), 1.26(0.88,1.81), 1.25(0.71,2.19) by 6 h,12 h, 18 h, 24 h cutoff value. The risk of referral cesarean delivery and length of stay ≥ 90%th increased with cutoff value. Other outcomes were showed in Table 5, Fig. 3. |
Table 3
Adverse outcomes in the first stage of labor in multiparous women. (n = 7109)
| Duration of First labor stage | Linear trend X2 | P |
6 h | 6-11.9 h | 12-17.9 h | 18-23.9 h | ≥ 24 h |
Overall outcomes | 714(21.0) | 588(23.4) | 236(28.8) | 81(35.5) | 58(38.4) | 57.64 | 0.001 |
Maternal outcomes | 246(7.2) | 221(8.8) | 113(13.8) | 46(20.2) | 45(29.8) | 121.38 | 0.001 |
Referral cesarean delivery | 28(0.8) | 29(1.2) | 20(2.4) | 13(5.7) | 8(5.3) | 50.97 | 0.001 |
Instrumental delivery | 77(2.3) | 72(2.9) | 35(4.3) | 12(5.3) | 11(7.3) | 23.46 | 0.001 |
Postpartum hemorrhage | 72(2.5) | 53(2.5) | 18(2.6) | 9(4.7) | 3(2.3) | 0.73 | 0.393 |
Lacerations(III or IV) | 34(1.1) | 23(1.0) | 14(1.9) | 4(2.0) | 3(2.3) | 3.76 | 0.053 |
Length of stay ≥ 90%th | 100(2.9) | 100(4.0) | 67 (8.2) | 31(13.6) | 34(22.5) | 160.81 | 0.001 |
Neonatal outcomes | 543(16.0) | 435(17.3) | 158(19.3) | 49(21.5) | 28(18.5) | 7.75 | 0.005 |
NICU | 184(5.4) | 150(6.0) | 54(6.6) | 16(7.0) | 7(4.6) | 1.14 | 0.285 |
Shoulder dystocia | 76(2.3) | 73(3.0) | 20(2.5) | 10(4.5) | 6(4.1) | 4.33 | 0.037 |
Apgar ≤ 7(5 min) | 24(0.7) | 42(1.7) | 15(1.8) | 5(2.2) | 3(2.0) | 12.66 | 0.001 |
Neonatal resuscitation | 354(11.0) | 287(12.2) | 101(13.3) | 31(15.3) | 17(13.1) | 5.77 | 0.016 |
Assisted ventilation | 72(2.2) | 66(2.8) | 31(4.1) | 8(3.9) | 4(2.7) | 7.13 | 0.008 |
Data was presented as n(%). Mantel Haenszel test was used for Linear trend X2 analyses. |
Table 4
Risks of adverse outcomes in the first stage of labor in multiparous women.
Duration of First labor stage |
6-11.9 h | | 12-17.9 h | | 18-23.9 h | | ≥ 24 h | |
| ARR(95%CI) | P | ARR(95%CI) | P | ARR(95%CI) | P | ARR(95%CI) | P |
Overall outcomes | 1.10(0.92,1.31) | 0.30 | 1.33(1.04,1.70) | 0.03 | 1.80(1.21,2.68) | 0.004 | 2.57(1.60,4.15) | 0.001 |
Maternal outcomes | 1.31(1.01,1.71) | 0.04 | 2.42(1.74,3.37) | 0.001 | 3.15(1.92,5.18) | 0.001 | 5.52(3.19,9.58) | 0.001 |
Referral cesarean delivery | 1.36(0.69,2.69) | 0.38 | 2.66(1.22,5.76) | 0.01 | 6.22(2.63,14.71) | 0.001 | 4.85(1.53,15.41) | 0.007 |
Instrumental delivery | 1.08(0.65,1.80) | 0.76 | 2.18(1.21,3.93) | 0.01 | 2.48(1.01,6.14) | 0.049 | 1.97(0.58,6.65) | 0.28 |
Postpartum hemorrhage | 0.93(0.58,1.49) | 0.76 | 1.13(0.58,2.18) | 0.72 | 1.48(0.57,3.87) | 0.42 | 1.07(0.25,4.58) | 0.93 |
Lacerations(III or IV) | 0.66(0.30,1.44) | 0.29 | 1.65(0.69,3.94) | 0.26 | 1.29(0.29,5.78) | 0.74 | 1.30(0.16,10.32) | 0.80 |
Length of stay ≥ 90%th | 2.09(1.43,3.05) | 0.001 | 4.02(2.54,6.36) | 0.001 | 7.06(3.82,13.02) | 0.001 | 13.41(6.97,25.80) | 0.001 |
Neonatal outcomes | 1.04(0.85,1.26) | 0.73 | 0.95(0.71,1.27) | 0.71 | 1.28(0.81,2.02) | 0.30 | 1.27(0.71,2.25) | 0.42 |
NICU | 1.45(1.02,2.04) | 0.04 | 1.34(0.80,2.23) | 0.26 | 1.47(0.64,3.40) | 0.37 | 0.63(0.15,2.67) | 0.53 |
Shoulder dystocia | 1.24(0.77,2.00) | 0.37 | 0.81(0.37,1.76) | 0.59 | 2.64(1.14,6.14) | 0.02 | 1.02(0.23,4.46) | 0.98 |
Apgar ≤ 7(5 min) | 3.18(1.43,7.10) | 0.005 | 2.77(0.96,7.97) | 0.06 | 0(0,0) | 0.99 | 5.30(1.09,25.87) | 0.04 |
Neonatal resuscitation | 0.95(0.76,1.19) | 0.66 | 0.81(0.57,1.16) | 0.25 | 1.11(0.64,1.91) | 0.72 | 1.49(0.79,2.81) | 0.22 |
Assisted ventilation | 1.56(0.95,2.55) | 0.08 | 1.96(1.02,3.75) | 0.04 | 1.83(0.62,5.38) | 0.27 | 2.45(0.72,8.37) | 0.15 |
Multivariable logistic regression model was used to assess the relationship between the duration of labor stage and adverse delivery outcomes, 6 h as a reference; Adjusted Gestational age, Maternal age, Maternal Height, Gestational weight gain, Maternal BMI, Gravidity, Parity, Baby weight, baby height, Ethnicity, Epidural, anesthesia, Induction, Oxytocin.
Table 5
Risks of adverse outcomes in different cutoff value of the first labor stage in multiparous women.
| 6 h | | 12 h | | 18 h | | 24 h | |
| ARR(95%CI) | P | ARR(95%CI) | P | ARR(95%CI) | P | ARR(95%CI) | P |
Overall outcomes | 1.23(1.05,1.43) | 0.01 | 1.48(1.22,1.80) | 0.001 | 1.92(1.41,2.59) | 0.001 | 2.33(1.45,3.72) | 0.001 |
Maternal outcomes | 1.76(1.40,2.22) | 0.001 | 2.55(1.98,3.28) | 0.001 | 3.07(2.13,4.40) | 0.001 | 4.05(2.39,6.86) | 0.001 |
Referral cesarean delivery | 2.1(1.16,3.80) | 0.01 | 3.14(1.84,5.35) | 0.001 | 4.15(2.17,7.93) | 0.001 | 3.00(1.03,8.78) | 0.04 |
Instrumental delivery | 1.43(0.93,2.22) | 0.11 | 2.13(1.34,3.41) | 0.002 | 1.92(0.94,3.93) | 0.08 | 1.58(0.48,5.18) | 0.45 |
Postpartum hemorrhage | 1.01(0.67,1.54) | 0.96 | 1.24(0.73,2.08) | 0.43 | 1.35(0.61,2.99) | 0.46 | 1.06(0.25,4.45) | 0.94 |
Lacerations(III or IV) | 0.93(0.49,1.77) | 0.81 | 1.83(0.88,3.78) | 0.10 | 1.36(0.41,4.57) | 0.62 | 1.35(0.18,10.36) | 0.77 |
Length of stay ≥ 90%th | 3.05(2.18,4.26) | 0.001 | 3.87(2.79,5.37) | 0.001 | 5.27(3.44,8.08) | 0.001 | 6.87(3.78,12.49) | 0.001 |
Neonatal outcomes | 1.04(0.87,1.24) | 0.68 | 1.03(0.82,1.30) | 0.80 | 1.26(0.88,1.81) | 0.20 | 1.25(0.71,2.19) | 0.45 |
NICU | 1.39(1.01,1.91) | 0.04 | 1.07(0.70,1.62) | 0.76 | 0.93(0.46,1.90) | 0.84 | 0.52(0.13,2.16) | 0.37 |
Shoulder dystocia | 1.23(0.79,1.91) | 0.37 | 1.06(0.62,1.82) | 0.83 | 1.85(0.91,3.74) | 0.09 | 0.90(0.21,3.83) | 0.88 |
Apgar ≤ 7(5 min) | 2.95(1.37,6.38) | 0.006 | 1.23(0.55,2.74) | 0.61 | 0.84(0.20,3.59) | 0.82 | 2.61(0.60,11.33) | 0.20 |
Neonatal resuscitation | 0.95(0.77,1.17) | 0.61 | 0.97(0.73,1.27) | 0.81 | 1.30(0.86,1.97) | 0.21 | 1.55(0.83,2.89) | 0.17 |
Assisted ventilation | 1.69(1.08,2.65) | 0.02 | 1.59(0.95,2.65) | 0.08 | 1.51(0.68,3.37) | 0.31 | 1.78(0.54,5.85) | 0.35 |
Multivariable logistic regression model was used to assess risks of cutoff value of labor stage for adverse delivery outcomes. Adjusted Gestational age, Maternal age, Maternal Height, Gestational weight gain, Maternal BMI, Gravidity, Parity, Baby weight, baby height, Ethnicity, Epidural, anesthesia, Induction, Oxytocin. |
The second stage was stratified to < 1 h, 1-1.9 h, 2-2.9 h, 3-3.9 h, ≥ 4 h. With the increase of second stage of labor, the rate of overall adverse outcomes increased from 20.0%, 30.7%, 38.5%, 61.2%, to 69.6% (X2 = 349.70, P0.001). The rate of maternal adverse outcomes increased from 5.9%, 14.6%, 25.2%, 45.0%, to 64.4% (X2 = 821.97, P0.001); The rate of neonatal adverse outcomes was 16.0%, 19.6%, 21.2%, 31.8%, 27.4%, increased significantly (X2 = 38.06, P0.001). There were significant differences in the rate of referral cesarean delivery, instrumental delivery, postpartum hemorrhage, laceration, length of stay ≥ 90%th, NICU, Apgar ≤ 7(5 min), neonatal resuscitation, assisted ventilation in second labor stage (Table 6, Fig. 4). With < 1 h as the reference group of second stage, ARR (95% CI) of 1-1.9 h, 2-2.9 h, 3-3.9 h, 4 h were 1.89 (1.50, 2.39), 2.22 (1.55, 3.18), 10.64 (6.09, 18.59), 11.75 (6.55, 21.08) in overall adverse outcomes; ARR(95%CI) were 2.51(1.83,3.44), 4.69(3.09,7.12), 13.87(8.21,23.44), 28.63(16.26,50.40) in maternal outcomes; ARR(95%CI) were 1.46(1.12,1.91), 1.28(0.83,1.98), 3.89(2.33,6.49), 1.68(0.91,3.10) in neonatal outcomes; others showed in Table 7, Fig. 5. The cutoff value of second stage on the risk of adverse outcomes, ARR (95% CI) of overall adverse outcomes were 2.71 (2.25, 3.26), 4.08 (3.15, 5.28), 9.51 (6.33, 14.28), 9.31 (5.20, 16.65) at 1 h, 2 h, 3 h, 4 h; ARR of maternal adverse outcomes were 4.63(3.64,5.87), 7.80(5.85,10.41), 14.11(9.59,20.78), 18.24(10.47,31.78); ARR of neonatal adverse outcomes were 1.61(1.30,2.00), 1.75(1.30,2.35), 2.48(1.68,3.66), 1.48 (0.81,2.73). Others were showed in Table 8, Fig. 5. |
Table 6
Adverse outcomes in the second stage of labor in multiparous women. (n = 7109)
| Duration of second labor stage | Linear trend X2 | P |
1 h | 1-1.9 h | 2-2.9 h | 3-3.9 h | ≥ 4 h |
Overall outcomes | 1159(20.0) | 238(30.7) | 107(38.5) | 79(61.2) | 94(69.6) | 349.70 | 0.001 |
Maternal outcomes | 343(5.9) | 113(14.6) | 70(25.2) | 58(45.0) | 87(64.4) | 821.97 | 0.001 |
Referral cesarean delivery | 6(0.1) | 13(1.7) | 17(6.1) | 18(14.0) | 44(32.6) | 989.84 | 0.001 |
Instrumental delivery | 88(1.5) | 37(4.8) | 28(10.1) | 25(19.4) | 29(21.5) | 375.02 | 0.001 |
Postpartum hemorrhage | 90(1.8) | 25(3.8) | 6(2.7) | 12(10.4) | 22(19.0) | 130.31 | 0.001 |
Lacerations(III or IV) | 48(0.9) | 11(1.6) | 6(2.5) | 6(5.8) | 7(7.1) | 46.88 | 0.001 |
Length of stay ≥ 90%th | 150(2.6) | 54(7.0) | 38(13.7) | 34(26.4) | 56(41.5) | 614.33 | 0.001 |
Neonatal outcomes | 924(16.0) | 152(19.6) | 59(21.2) | 41(31.8) | 37(27.4) | 38.06 | 0.001 |
NICU | 295(5.1) | 55(7.1) | 28(10.1) | 18(14.0) | 15(11.1) | 36.42 | 0.001 |
Shoulder dystocia | 150(2.6) | 22(2.9) | 7(2.6) | 4(3.3) | 2(1.5) | 0.05 | 0.83 |
Apgar ≤ 7(5 min) | 48(0.8) | 17(2.2) | 6(2.2) | 13(10.1) | 5(3.7) | 64.22 | 0.001 |
Neonatal resuscitation | 609(11.2) | 95(13.1) | 30(11.9) | 30(25.2) | 26(21.1) | 24.22 | 0.001 |
Assisted ventilation | 123(2.3) | 23(3.2) | 10(4.0) | 14(11.8) | 11(8.9) | 48.11 | 0.001 |
Data was presented as n(%). Mantel Haenszel test was used for Linear trend X2 analyses. |
Table 7
Risks of adverse outcomes in the second stage of labor in multiparous women.
Duration of second labor stage n(%) |
| 1-1.9 h | | 2-2.9 h | | 3-3.9 h | | ≥ 4 h | |
| ARR(95%CI) | P | ARR(95%CI) | P | ARR(95%CI) | P | ARR(95%CI) | P |
Overall outcomes | 1.89(1.50,2.39) | 0.001 | 2.22(1.55,3.18) | 0.001 | 10.64(6.09,18.59) | 0.001 | 11.75(6.55,21.08) | 0.001 |
Maternal outcomes | 2.51(1.83,3.44) | 0.001 | 4.69(3.09,7.12) | 0.001 | 13.87(8.21,23.44) | 0.001 | 28.63(16.26,50.40) | 0.001 |
Referral cesarean delivery | 19.34(5.25,71.28) | 0.001 | 62.88(16.96,233.14) | 0.001 | 243.00(65.88,896.26) | 0.001 | 426.23(118.39,1534.54) | 0.001 |
Instrumental delivery | 2.80(1.51,5.19) | 0.001 | 5.73(2.73,12.07) | 0.001 | 19.38(9.23,40.70) | 0.001 | 18.55(8.41,40.94) | 0.001 |
Postpartum hemorrhage | 1.79(0.99,3.23) | 0.06 | 1.27(0.45,3.61) | 0.65 | 6.11(2.79,13.35) | 0.001 | 10.46(5.08,21.54) | 0.001 |
Lacerations(III or IV) | 1.31(0.48,3.57) | 0.59 | 2.85(0.92,8.85) | 0.07 | 1.94(0.25,15.20) | 0.53 | 11.49(3.96,33.37) | 0.001 |
Length of stay ≥ 90%th | 3.09(2.03,4.71) | 0.001 | 7.01(4.21,11.68) | 0.001 | 17.01(9.45,30.64) | 0.001 | 30.78(17.11,55.37) | 0.001 |
Neonatal outcomes | 1.46(1.12,1.91) | 0.005 | 1.28(0.83,1.98) | 0.27 | 3.89(2.33,6.49) | 0.001 | 1.68(0.91,3.10) | 0.10 |
NICU | 1.93(1.22,3.06) | 0.005 | 2.13(1.04,4.37) | 0.04 | 7.25(3.63,14.45) | 0.001 | 3.72(1.52,9.08) | 0.004 |
Shoulder dystocia | 1.32(0.73,2.37) | 0.36 | 0.67(0.20,2.22) | 0.51 | 1.03(0.23,4.55) | 0.97 | 0.00(0.00,.) | 0.997 |
Apgar ≤ 7(5 min) | 4.00(1.63,9.86) | 0.003 | 2.82(0.62,12.90) | 0.18 | 36.35(14.17,93.24) | 0.001 | 10.53(2.80,39.61) | 0.001 |
Neonatal resuscitation | 1.31(0.96,1.79) | 0.09 | 1.16(0.69,1.94) | 0.58 | 3.61(2.08,6.26) | 0.001 | 1.56(0.78,3.14) | 0.21 |
Assisted ventilation | 1.80(0.93,3.47) | 0.08 | 2.62(1.08,6.38) | 0.03 | 12.07(5.68,25.66) | 0.001 | 3.89(1.33,11.42) | 0.01 |
Multivariable logistic regression model was used to assess the relationship between the duration of labor stage and adverse delivery outcomes, 1 h as a reference; Adjusted Gestational age, Maternal BMI, Gravidity, Parity, Baby weight, baby height, Ethnicity, Epidural, anesthesia, Oxytocin.
Table 8
Risks of adverse outcomes in different cutoff value of the second labor stage in multiparous women.
Duration of Second labor stage n(%) |
| 1 h | | 2 h | | 3 h | | 4 h | |
| ARR(95%CI) | P | ARR(95%CI) | P | ARR(95%CI) | P | ARR(95%CI) | P |
Overall outcomes | 2.71(2.25,3.26) | 0.001 | 4.08(3.15,5.28) | 0.001 | 9.51(6.33,14.28) | 0.001 | 9.31(5.20,16.65) | 0.001 |
Maternal outcomes | 4.63(3.64,5.87) | 0.001 | 7.80(5.85,10.41) | 0.001 | 14.11(9.59,20.78) | 0.001 | 18.24(10.47,31.78) | 0.001 |
Referral cesarean delivery | 67.51(20.92,217.91) | 0.001 | 42.82(22.34,82.05) | 0.001 | 47.07(25.93,85.43) | 0.001 | 35.64(18.66,68.07) | 0.001 |
Instrumental delivery | 5.55(3.54,8.72) | 0.001 | 8.81(5.42,14.32) | 0.001 | 12.71(7.29,22.18) | 0.001 | 9.83(4.66,20.76) | 0.001 |
Postpartum hemorrhage | 2.78(1.80,4.30) | 0.001 | 3.85(2.35,6.32) | 0.001 | 7.10(4.10,12.27) | 0.001 | 8.28(4.11,16.68) | 0.001 |
Lacerations(III or IV) | 2.41(1.21,4.83) | 0.01 | 4.09(1.87,8.96) | 0.001 | 5.45(2.13,13.94) | 0.001 | 9.67(3.45,27.08) | 0.001 |
Length of stay ≥ 90%th | 6.23(4.54,8.54) | 0.001 | 9.96(7.04,14.11) | 0.001 | 14.31(9.40,21.78) | 0.001 | 16.18(9.28,28.22) | 0.001 |
Neonatal outcomes | 1.61(1.30,2.00) | 0.001 | 1.75(1.30,2.35) | 0.001 | 2.48(1.68,3.66) | 0.001 | 1.48(0.81,2.73) | 0.21 |
NICU | 2.52(1.76,3.61) | 0.001 | 3.18(2.01,5.02) | 0.001 | 4.65(2.68,8.09) | 0.001 | 2.85(1.18,6.87) | 0.02 |
Shoulder dystocia | 1.00(0.59,1.69) | 0.995 | 0.53(0.21,1.35) | 0.18 | 0.43(0.10,1.84) | 0.26 | 0(0,.) | 0.997 |
Apgar ≤ 7(5 min) | 6.68(3.30,13.54) | 0.001 | 7.83(3.84,15.99) | 0.001 | 14.76(6.92,31.51) | 0.001 | 4.27(1.24,14.73) | 0.02 |
Neonatal resuscitation | 1.48(1.15,1.90) | 0.002 | 1.68(1.20,2.36) | 0.003 | 2.40(1.56,3.69) | 0.001 | 1.40(0.70,2.81) | 0.34 |
Assisted ventilation | 2.96(1.84,4.77) | 0.001 | 4.38(2.55,7.54) | 0.001 | 6.36(3.42,11.82) | 0.001 | 2.65(0.92,7.59) | 0.07 |
Multivariable logistic regression model was used to assess risks of cutoff value of labor stage for adverse delivery outcomes. Adjusted Gestational age, Maternal BMI, Gravidity, Parity, Baby weight, baby height, Ethnicity, Epidural, anesthesia, Oxytocin.
The total labor stage was stratified to < 12 h, 12-23.9 h, and ≥ 24 h. With the increase of total labor stage, the rate of overall adverse outcomes were increased by 21.5%, 30.8%, 42.4% (X2 = 84.90, P0.001); The rate of material adverse outcomes were increased by 7.3%, 15.7%, 33.2% (X2 = 195.48, P0.001); The rate of neonatal adverse outcomes were increased by 16.4%, 20.0%, 19.6% (X2 = 8.61, P = 0.003). The rate were different in referral cesarean delivery, instrumental delivery, postpartum hemorrhage, laceration, length of stay ≥ 90%th, Apgar ≤ 7(5 min), neonatal resuscitation, assisted ventilation (Table 9, Fig. 6). With total labor stage < 12 h as the reference, ARR (95% CI) of overall adverse outcomes were 1.41(1.16,1.72), 3.17 (2.10,4.80) in 12-23.9 h, ≥ 24 h, the risk of maternal outcomes was 2.40(1.84,3.12), 6.57 (4.14,10.42), and the risk of neonatal outcomes was 1.01 (0.80,1.28), 1.41 (0.86,2.30), (Table 10, Fig. 7).
The risk of overall adverse outcomes was ARR (95% CI) :1.59 (1.32,1.91), compared < 12 hours and ≥ 12 h in total stage, and 24 hours was 0.34 (0.09,1.24); The risk of maternal adverse outcome was 2.84 (2.23,3.62) at 12 hours, but there was no effect on the neonatal adverse outcomes (Table 11, Fig. 7).
Table 9
Adverse outcomes in the total stage of labor in multiparous women. (n = 7109)
| Duration of total labor stage | Linear trend X2 | P |
12 h | 12-23.9 h | ≥ 24 h |
Overall outcomes | 1227(21.5) | 372(30.8) | 78(42.4) | 84.90 | 0.001 |
Maternal outcomes | 420(7.3) | 190(15.7) | 61(33.2) | 195.48 | 0.001 |
Referral cesarean delivery | 43(0.8) | 39(3.2) | 16(8.7) | 111.98 | 0.001 |
Instrumental delivery | 129(2.3) | 62(5.1) | 16(8.7) | 51.34 | 0.001 |
Postpartum hemorrhage | 113(2.3) | 34(3.3) | 8(5.1) | 6.86 | 0.009 |
Lacerations(III or IV) | 55(1.1) | 18(1.7) | 5(3.1) | 6.96 | 0.008 |
Length of stay ≥ 90%th | 172(3.0) | 116(9.6) | 44(23.9) | 239.48 | 0.001 |
Neonatal outcomes | 936(16.4) | 241(20.0) | 36(19.6) | 8.61 | 0.003 |
NICU | 313(5.5) | 89(7.4) | 9(4.9) | 2.91 | 0.088 |
Shoulder dystocia | 143(2.5) | 35(3.0) | 7(3.9) | 1.68 | 0.194 |
Apgar ≤ 7(5 min) | 58(1.0) | 27(2.2) | 4(2.2) | 11.83 | 0.001 |
Neonatal resuscitation | 615(11.4) | 154(13.9) | 21(13.1) | 4.62 | 0.032 |
Assisted ventilation | 131(2.4) | 44(4.0) | 6(3.8) | 7.70 | 0.006 |
Data was presented as n(%). Mantel Haenszel test was used for Linear trend X2 analyses. |
Table 10
Risks of adverse outcomes in the total stage of labor in multiparous women.
Duration of First and Second labor stage |
| 12-23.9 h | | ≥ 24 h | |
| ARR(95%CI) | P | ARR(95%CI) | P |
Overall outcomes | 1.41(1.16,1.72) | 0.001 | 3.17(2.10,4.80) | 0.001 |
Maternal outcomes | 2.40(1.84,3.12) | 0.001 | 6.57(4.14,10.42) | 0.001 |
Referral cesarean delivery | 3.89(2.19,6.92) | 0.001 | 10.85(4.94,23.83) | 0.001 |
Instrumental delivery | 2.59(1.62,4.13) | 0.001 | 3.38(1.39,8.19) | 0.007 |
Postpartum hemorrhage | 1.29(0.76,2.17) | 0.35 | 2.84(1.18,6.84) | 0.02 |
Lacerations(III or IV) | 1.39(0.64,3.02) | 0.41 | 2.34(0.53,10.40) | 0.26 |
Length of stay ≥ 90%th | 3.95(2.79,5.58) | 0.001 | 12.27(7.09,21.24) | 0.001 |
Neonatal outcomes | 1.01(0.80,1.28) | 0.94 | 1.41(0.86,2.30) | 0.17 |
NICU | 1.43(0.91,2.11) | 0.07 | 0.97(0.35,2.71) | 0.95 |
Shoulder dystocia | 0.91(0.52,1.59) | 0.74 | 1.06(0.32,3.54) | 0.93 |
Apgar ≤ 7(5 min) | 1.73(0.82,3.66) | 0.15 | 2.03(0.46,8.91) | 0.35 |
Neonatal resuscitation | 0.87(0.66,1.16) | 0.34 | 1.38(0.79,2.42) | 0.26 |
Assisted ventilation | 1.43(0.84,2.43) | 0.19 | 2.48(0.95,6.44) | 0.06 |
Multivariable logistic regression model was used to assess the relationship between the duration of labor stage and adverse delivery outcomes, 12 h as a reference; Adjusted Gestational age, Maternal age, Maternal Height, Maternal BMI, Gravidity, Parity, Baby weight, baby height, Epidural, anesthesia, Induction, Oxytocin.
Table 11
Risks of adverse outcomes in different cutoff value of the total labor stage in multiparous women.
Duration of First and Second labor stage |
| 12 h | | 24 h | |
| ARR(95%CI) | P | ARR(95%CI) | P |
Overall outcomes | 1.59(1.32,1.91) | 0.001 | 0.34(0.09,1.24) | 0.10 |
Maternal outcomes | 2.84(2.23,3.62) | 0.001 | 118189641(0,.) | 0.999 |
Referral cesarean delivery | 4.79(2.81,8.14) | 0.001 | 14287407(0,.) | 0.999 |
Instrumental delivery | 2.69(1.73,4.19) | 0.001 | 28114859(0,.) | 0.999 |
Postpartum hemorrhage | 1.48(0.92,2.38) | 0.11 | 36104387(0,.) | 0.999 |
Lacerations(III or IV) | 1.50(0.72,3.09) | 0.28 | 13908484(0,.) | 0.999 |
Length of stay ≥ 90%th | 4.84(3.52,6.67) | 0.001 | 50335087(0,.) | 0.999 |
Neonatal outcomes | 1.06(0.85,1.32) | 0.61 | 0.24(0.07,0.87) | 0.03 |
NICU | 1.37(0.94,1.99) | 0.10 | 0.36(0.04,2.96) | 0.34 |
Shoulder dystocia | 0.93(0.55,1.57) | 0.79 | 28737306(0,.) | 0.999 |
Apgar ≤ 7(5 min) | 1.77(0.87,3.59) | 0.11 | 8482568(0,.) | 0.999 |
Neonatal resuscitation | 0.94(0.72,1.22) | 0.63 | 0.28(0.07,1.08) | 0.07 |
Assisted ventilation | 1.56(0.96,2.56) | 0.07 | 30289878(0,.) | 0.999 |
Multivariable logistic regression model was used to assess risks of cutoff value of labor stage for adverse delivery outcomes. Adjusted Gestational age, Maternal age, Maternal Height, Maternal BMI, Gravidity, Parity, Baby weight, baby height, Epidural, anesthesia, Induction, Oxytocin.