Perinatal and maternal morbidity and mortality after attempted operative vaginal delivery at midpelvic station

Giulia M. Muraca; Yasser Sabr; Sarka Lisonkova; Amanda Skoll; Rollin Brant; Geoffrey W. Cundiff; K.S. Joseph

doi:10.1503/cmaj.161156

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Figure 1:
Derivation of the cohort for this study. The sum of individual exclusions may exceed the total at each point because some deliveries were excluded for multiple reasons. *Excluding Quebec. †Midpelvic OVD v. cesarean delivery indicated for dystocia. ‡Midpelvic OVD v. cesarean delivery indicated for fetal distress. OVD = operative vaginal delivery.
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Figure 2:
Effects of midpelvic operative vaginal delivery (compared with cesarean delivery in labour) on composite severe perinatal and maternal morbidity and mortality, and trauma among women with and without a prolonged second stage of labour. (A) Women with dystocia and (B) women with fetal distress. AOR = adjusted odds ratio, CI = confidence interval.

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Table 1:

No. of deliveries by mode, and by maternal, infant and obstetric characteristics among women delivering term singletons by midpelvic operative vaginal delivery or cesarean delivery with labour in Canada^* from 2003 to 2013

Maternal/neonatal characteristic	No. of deliveries (% of total no. of deliveries per characteristic level)^† n = 187 234				Total no. of deliveries per characteristic level	p value
Maternal/neonatal characteristic	Attempted midpelvic forceps n = 24 274	Attempted midpelvic vacuum n = 23 525	Attempted midpelvic sequential n = 4012	Cesarean n = 135 423	Total no. of deliveries per characteristic level	p value
Maternal age, yr						< 0.001
< 20	888 (11.3)	1001 (12.8)	199 (2.5)	5758 (73.4)	7846
20–24	3359 (11.8)	3545 (12.5)	676 (2.4)	20 821 (73.3)	28 401
25–29	7850 (13.6)	7242 (12.6)	1376 (2.4)	41 198 (71.4)	57 666
30–34	8144 (13.5)	7670 (12.7)	1236 (2.1)	43 194 (71.7)	60 244
35–39	3447 (12.6)	3413 (12.5)	437 (1.6)	20 070 (73.3)	27 367
≥ 40	586 (10.3)	654 (11.5)	88 (1.5)	4382 (76.7)	5710
Parity						< 0.001
0	15 881 (13.6)	13 905 (11.9)	2673 (2.3)	84 561 (72.3)	117 020
1	2310 (10.8)	4765 (22.2)	415 (1.9)	13 970 (65.1)	21 460
2–3	577 (8.6)	1783 (26.5)	128 (1.9)	4253 (63.1)	6741
≥ 4	67 (6.0)	282 (25.1)	17 (1.5)	759 (67.5)	1125
Missing	5439 (13.3)	2790 (6.8)	779 (1.9)	31 880 (78.0)	40 888
Previous cesarean						< 0.001
Yes	51 (2.1)	49 (2.0)	17 (0.7)	2297 (95.2)	2414
No	24 223 (13.1)	23 476 (12.7)	3995 (2.2)	133 126 (72.0)	184 820
Gestational age, wk						< 0.001
37–38	4007 (14.5)	4347 (15.7)	587 (2.1)	18 675 (67.6)	27 616
39–41	20 267 (12.7)	19 178 (12.0)	3425 (2.1)	116 748 (73.1)	159 618
Birth weight, g						< 0.001
< 2500	208 (8.1)	354 (13.8)	26 (1.0)	1979 (77.1)	2567
2500–2999	2671 (14.1)	3310 (17.3)	367 (1.9)	12 641 (66.6)	18 989
3000–3999	17 868 (13.8)	16 927 (13.1)	3001 (2.3)	91 849 (70.8)	129 645
≥ 4000	3527 (9.8)	2934 (8.1)	618 (1.7)	28 954 (80.4)	36 033
Epidural						< 0.001
Yes	20 924 (15.3)	16 747 (12.2)	3159 (2.3)	95 941 (70.2)	136 771
No	3350 (6.6)	6778 (13.4)	853 (1.7)	39 482 (78.2)	50 463
Indication						< 0.001
Dystocia	10 017 (13.1)	6401 (8.3)	1572 (2.1)	58 765 (76.6)	76 755
Fetal distress	14 257 (12.9)	17 124 (15.5)	2440 (2.2)	76 658 (69.4)	110 479
Prolonged 2nd stage of labour						< 0.001
Yes	7855 (27.2)	4887 (16.9)	1147 (4.0)	15 034 (52.0)	28 923
No	16 419 (10.4)	18 638 (11.8)	2865 (1.8)	120 389 (76.0)	158 311
Successful OVD^‡ trial (% of all OVD)						< 0.001
Dystocia	8611 (86.0)	4849 (75.8)	1094 (69.6)	–	–
Fetal distress	12 836 (90.0)	15 549 (90.8)	1874 (76.8)	–	–

Note: OVD = operative vaginal delivery.
↵* Excludes the province of Quebec.
↵† Unless specified otherwise.
↵‡ Successful OVDs express the no. (%) of successful OVDs in a specific category divided by the no. of attempted OVDs in that category stratified by indication (dystocia or fetal distress).

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Table 2:

Perinatal and maternal outcomes by attempted midpelvic operative vaginal and cesarean deliveries with dystocia and prolonged second stage of labour (n = 17 484)^*^†

Outcome	No. (%) of cesarean deliveries n = 9300	Attempted midpelvic forceps delivery n = 4741		Attempted midpelvic vacuum delivery n = 2780		Attempted midpelvic sequential operative vaginal delivery n = 663

		No. (%)	AOR (95% CI)	No. (%)	AOR (95% CI)	No. (%)	AOR (95% CI)
Severe perinatal morbidity/mortality	61 (0.7)	52 (1.1)	1.81 (1.24 to 2.64)	32 (1.2)	1.81 (1.17 to 2.80)	13 (2.0)	3.19 (1.73 to 5.88)

Stillbirth	0 (0.0)	0 (0.0)	–	< 5 (< 0.2)	–	0 (0.0)	–

Neonatal death	0 (0.0)	< 5 (< 0.1)	–	< 5 (< 0.2)	–	0 (0.0)	–

Neonatal convulsion	16 (0.2)	8 (0.2)	0.98 (0.42 to 2.29)^†††	6 (0.2)	1.26 (0.49 to 3.21)^†††	< 5 (< 0.8)	1.76 (0.40 to 7.65)^†††

Assisted ventilation (endotracheal)	35 (0.4)	10 (0.2)	0.55 (0.27 to 1.13)	9 (0.3)	0.80 (0.38 to 1.67)	< 5 (< 0.8)	0.74 (0.18 to 3.08)

Severe birth trauma^‡	16 (0.2)	35 (0.7)	5.01 (2.75 to 9.15)	19 (0.7)	4.47 (2.27 to 8.80)	9 (1.4)	9.46 (4.11 to 21.8)

Respiratory distress^§	302 (3.3)	188 (4.0)	1.25 (1.04 to 1.51)	116 (4.2)	1.29 (1.03 to 1.61)	47 (7.1)	2.29 (1.66 to 3.16)

Assisted ventilation^¶	140 (1.5)	63 (1.3)	0.81 (0.60 to 1.10)	37 (1.3)	0.79 (0.54 to 1.14)	12 (1.8)	1.12 (0.61 to 2.05)

Fetal asphyxia	23 (0.3)	9 (0.2)	0.77 (0.36 to 1.66)^†††	< 5 (< 0.2)	0.44 (0.13 to 1.45)^†††	< 5 (< 0.8)	1.22 (0.29 to 5.19)^†††

Birth asphyxia	19 (0.2)	8 (0.2)	0.83 (0.36 to 1.89)^†††	12 (0.4)	2.12 (1.03 to 4.37)^†††	< 5 (< 0.8)	1.48 (0.34 to 6.36)^†††

Intracranial hemorrhage due to hypoxia	< 5 (< 0.1)	< 5 (< 0.1)	1.96 (0.28 to 13.9)^†††	8 (0.3)	13.4 (2.85 to 63.2)^†††	< 5 (< 0.8)	14.1 (1.98 to 100)^†††

Cardiac failure/dysrhythmia	120 (1.3)	67 (1.4)	1.09 (0.80 to 1.47)	47 (1.7)	1.14 (0.80 to 1.62)	18 (2.7)	1.91 (1.15 to 3.18)

Severe cerebral morbidity^**	16 (0.2)	18 (0.4)	2.21 (1.13 to 4.34)^†††	< 5 (< 0.2)	0.42 (0.10 to 1.82)^†††	< 5 (< 0.8)	3.52 (1.17 to 10.6)^†††

Birth trauma^††	194 (2.1)	304 (6.4)	3.23 (2.68 to 3.88)	307 (11.0)	5.40 (4.47 to 6.52)	100 (15.1)	7.92 (6.11 to 10.3)

Meconium aspiration syndrome	11 (0.1)	9 (0.2)	1.61 (0.67 to 3.88)^†††	10 (0.4)	3.05 (1.29 to 7.19)^†††	< 5 (< 0.8)	2.56 (0.57 to 11.6)^†††

Bacterial sepsis	29 (0.3)	28 (0.6)	1.90 (1.13 to 3.20)^†††	6 (0.2)	0.69 (0.29 to 1.67)^†††	0 (0.0)	–

Severe maternal morbidity/mortality	153 (1.7)	83 (1.8)	1.19 (0.91 to 1.57)	38 (1.4)	0.87 (0.60 to 1.25)	13 (2.0)	1.26 (0.71 to 2.25)

Maternal death	0 (0.0)	0 (0.0)	–	0 (0.0)	–	0 (0.0)	–

Severe postpartum hemorrhage^‡‡	97 (1.0)	64 (1.4)	1.51 (1.09 to 2.09)	26 (0.9)	0.92 (0.59 to 1.44)	13 (2.0)	2.00 (1.10 to 3.62)

Shock	< 5 (< 0.1)	< 5 (< 0.1)	0.98 (0.18 to 5.36)^†††	< 5 (< 0.2)	0.84 (0.09 to 7.49)^†††	0 (0.0)	–

Sepsis	20 (0.2)	8 (0.2)	0.78 (0.35 to 1.78)^†††	5 (0.2)	0.84 (0.31 to 2.23)^†††	0 (0.0)	–

Cardiac complication^§§	36 (0.4)	7 (0.2)	0.38 (0.17 to 0.86)^†††	6 (0.2)	0.56 (0.23 to 1.32)^†††	0 (0.0)	–

Acute renal failure	< 5 (< 0.1)	< 5 (< 0.1)	–	< 5 (< 0.2)	–	0 (0.0)	–

Obstetric embolism	5 (0.1)	0 (0.0)	–	< 5 (< 0.2)	–	0 (0.0)	–

Evacuation incisional hematoma	< 5 (< 0.1)	< 5 (< 0.1)	–	0 (0.0)	–	0 (0.0)	–

Obstetric trauma^¶¶	589 (6.3)	1085 (22.9)	4.51 (4.04 to 5.02)	427 (15.4)	2.70 (2.35 to 3.09)	147 (22.2)	4.24 (3.46 to 5.19)

Perineal laceration 3rd/4th degree	< 5 (< 0.1)	888 (18.7)	–	341 (12.3)	–	135 (20.4)	–

Uterine incision extension	268 (2.9)	13 (0.3)	0.11 (0.06 to 0.19)	21 (0.8)	0.29 (0.18 to 0.46)	< 5 (< 0.8)	0.06 (0.01 to 0.40)

Postpartum infection^***	126 (1.4)	34 (0.7)	0.54 (0.37 to 0.79)	22 (0.8)	0.60 (0.38 to 0.95)	8 (1.2)	0.87 (0.42 to 1.80)

Postpartum hemorrhage	668 (7.2)	792 (16.7)	2.77 (2.48 to 3.10)	323 (11.6)	1.61 (1.39 to 1.86)	111 (16.7)	2.54 (2.03 to 3.17)

Note: AOR = adjusted odds ratio, CI = confidence interval, CNS = central nervous system, PNS = peripheral nervous system.
↵* Adjusted odds ratios were estimated using logistic regression, with cesarean delivery as the reference group.
↵† All models were adjusted for maternal age, parity, birth weight, previous cesarean delivery, province and fiscal year.
↵‡ We included intracranial laceration and hemorrhage, skull fracture, severe injury to the CNS, severe injury to the PNS, long bone injury, subaponeurotic (subgaleal) hemorrhage, and injury to the liver and spleen.
↵§ We included respiratory distress syndrome, transient tachypnea of the newborn and other neonatal respiratory distress.
↵¶ We included resuscitation, chest compression, endotracheal respiratory assistance, mechanical respiratory assistance, forced oxygenation, intubation, mechanical ventilation and drugs for resuscitation.
↵** We included hypoxic ischemic encephalopathy, cerebral ischemia, cerebral irritability and cerebral depression.
↵†† We included intracranial hemorrhage/laceration, and injury to the CNS/PNS, scalp and skeleton.
↵‡‡ We included a combination of postpartum hemorrhage and transfusion codes.
↵§§ We included cardiac arrest, cardiac failure, myocardial infarction and pulmonary embolism.
↵¶¶ We included severe perineal lacerations (3rd/4th degree), cervical laceration, high vaginal laceration, injury to pelvic organ/joint, pelvic hematoma and extension of uterine incision.
↵*** We included sepsis, infection of obstetric surgical wound, infection of the genital tract following delivery, infection of the urinary tract following delivery, infections of the genitourinary tract following delivery, pyrexia of unknown origin following delivery and other specified puerperal infection.
↵††† Crude OR is reported because AOR was undefined owing to small numbers.

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Table 3:

Perinatal and maternal outcomes by attempted midpelvic operative vaginal and cesarean deliveries with fetal distress and prolonged second stage of labour (n = 11 439)^*^†

Outcome	No. (%) of cesarean deliveries n = 5734	Attempted midpelvic forceps delivery n = 3114		Attempted midpelvic vacuum delivery n = 2107		Attempted midpelvic sequential operative vaginal delivery n = 484

		No. (%)	AOR (95% CI)	No. (%)	AOR (95% CI)	No. (%)	AOR (95% CI)
Severe perinatal morbidity/mortality	103 (1.8)	68 (2.2)	1.26 (0.92 to 1.72)	39 (1.9)	1.01 (0.69–1.48)	21 (4.3)	2.62 (1.15 to 4.06)

Stillbirth	0 (0.0)	0 (0.0)	–	0 (0.0)	–	0 (0.0)	–

Neonatal death	< 5 (< 0.1)	< 5 (< 0.2)	–	0 (0.0)	–	0 (0.0)	–

Neonatal convulsions	23 (0.4)	7 (0.2)	0.56 (0.24 to 1.31)^†††	6 (0.3)	0.71 (0.29 to 1.74)^†††	< 5 (< 1.0)	1.03 (0.24 to 4.38)^†††

Assisted ventilation (endotracheal)	80 (1.4)	29 (0.9)	0.64 (0.42 to 0.98)	15 (0.7)	0.44 (0.25 to 0.76)	8 (1.7)	1.13 (0.54 to 2.37)

Severe birth trauma^‡	9 (0.2)	37 (1.2)	10.4 (4.84 to 22.5)	22 (1.0)	9.05 (3.97 to 20.6)	12 (2.5)	24.3 (9.72 to 60.8)

Respiratory distress^§	386 (6.7)	197 (6.3)	0.95 (0.79 to 1.13)	133 (6.3)	0.97 (0.79 to 1.20)	48 (9.9)	1.54 (1.12 to 2.12)

Assisted ventilation^¶	198 (3.5)	67 (2.2)	0.59 (0.45 to 0.79)	49 (2.3)	0.57 (0.41 to 0.78)	17 (3.5)	0.91 (0.55 to 1.51)

Fetal asphyxia	63 (1.1)	18 (0.6)	0.53 (0.32 to 0.91)	17 (0.8)	0.69 (0.40 to 1.19)	7 (1.5)	1.33 (0.60 to 2.94)

Birth asphyxia	26 (0.5)	12 (0.4)	0.85 (0.43 to 1.69)^†††	6 (0.3)	0.63 (0.26 to 1.53)^†††	< 5 (< 1.0)	0.91 (0.22 to 3.85)^†††

Intracranial hemorrhage due to hypoxia	< 5 (< 0.1)	< 5 (< 0.2)	0.92 (0.17 to 5.03)^†††	< 5 (< 0.2)	1.36 (0.25 to 7.44)^†††	< 5 (< 1.0)	2.97 (0.33 to 26.6)^†††

Cardiac failure/dysrhythmia	209 (3.6)	172 (5.5)	1.54 (1.25 to 1.90)	80 (3.8)	0.90 (0.69 to 1.18)	38 (7.9)	2.09 (1.45 to 3.00)

Severe cerebral morbidity^**	17 (0.3)	7 (0.2)	0.76 (0.31 to 1.83)^†††	7 (0.3)	1.12 (0.46 to 2.71)^†††	5 (1.0)	3.51 (1.29 to 9.56)^†††

Birth trauma^††	154 (2.7)	253 (8.1)	3.26 (2.65 to 4.02)	269 (12.8)	5.09 (4.13 to 6.28)	99 (20.5)	9.47 (7.18 to 12.5)

Meconium aspiration syndrome	92 (1.6)	34 (1.1)	0.70 (0.47 to 1.04)	43 (2.0)	1.33 (0.91 to 1.94)	7 (1.5)	1.02 (0.47 to 2.24)

Bacterial sepsis	43 (0.8)	23 (0.7)	0.99 (0.59 to 1.64)	12 (0.6)	0.76 (0.40 to 1.44)	< 5 (< 1.0)	0.55 (0.13 to 2.27)

Severe maternal morbidity/ mortality	125 (2.2)	53 (1.7)	0.78 (0.56 to 1.09)	26 (1.2)	0.52 (0.33 to 0.80)	7 (1.5)	0.62 (0.29 to 1.35)

Maternal death	0 (0.0)	0 (0.0)	–	0 (0.0)	–	0 (0.0)	–

Severe postpartum hemorrhage^‡‡	72 (1.3)	42 (1.4)	1.09 (0.74 to 1.61)	21 (1.0)	0.73 (0.44 to 1.22)	< 5 (< 1.0)	0.61 (0.22 to 1.69)

Shock	< 5 (< 0.1)	0 (0.0)	–	0 (0.0)	–	0 (0.0)	–

Sepsis	21 (0.4)	5 (0.2)	0.44 (0.17 to 1.16)^†††	< 5 (< 0.2)	0.13 (0.02 to 0.96)^†††	< 5 (< 1.0)	0.56 (0.08 to 4.20)^†††

Cardiac complication^§§	28 (0.5)	6 (0.2)	0.41 (0.17 to 1.00)	< 5 (< 0.2)	0.36 (0.12 to 1.04)	< 5 (< 1.0)	0.90 (0.21 to 3.86)

Acute renal failure	< 5 (< 0.1)	0 (0.0)	–	< 5 (< 0.2)	–	0 (0.0)	–

Obstetric embolism	5 (0.1)	0 (0.0)	–	0 (0.0)	–	0 (0.0)	–

Evacuation incisional hematoma	< 5 (< 0.1)	< 5 (< 0.2)	–	0 (0.0)	–	0 (0.0)	–

Obstetric trauma^¶¶	464 (8.1)	710 (22.8)	3.34 (2.94 to 3.80)	329 (15.6)	1.99 (1.71 to 2.33)	111 (22.9)	3.23 (2.55 to 4.08)

Perineal laceration 3rd/4th degree	< 5 (< 0.1)	567 (18.2)	–	270 (12.8)	–	88 (18.2)	–

Uterine incision extension	219 (3.8)	16 (0.5)	0.13 (0.08 to 0.22)^†††	7 (0.3)	0.08 (0.04 to 0.18)^†††	11 (2.3)	0.59 (0.32 to 1.08)^†††

Postpartum infection^***	112 (2.0)	28 (0.9)	0.46 (0.30 to 0.70)	16 (0.8)	0.42 (0.25 to 0.72)	5 (1.0)	0.53 (0.21 to 1.31)

Postpartum hemorrhage	491 (8.6)	533 (17.1)	2.20 (1.92 to 2.51)	262 (12.4)	1.41 (1.19 to 1.66)	73 (15.1)	1.77 (1.35 to 2.31)

Note: AOR = adjusted odds ratio, CI = confidence interval, CNS = central nervous system, PNS = peripheral nervous system.
↵* Adjusted odds ratios were estimated using logistic regression, with cesarean delivery as the reference group.
↵† All models were adjusted for maternal age, parity, birth weight, previous cesarean delivery, province and fiscal year.
↵‡ We included intracranial laceration and hemorrhage, skull fracture, severe injury to the CNS, severe injury to the PNS, long bone injury, subaponeurotic (subgaleal) hemorrhage, and injury to the liver and spleen.
↵§ We included respiratory distress syndrome, transient tachypnea of the newborn and other neonatal respiratory distress.
↵¶ We included resuscitation, chest compression, endotracheal respiratory assistance, mechanical respiratory assistance, forced oxygenation, intubation, mechanical ventilation and drugs for resuscitation.
↵** We included hypoxic ischemic encephalopathy, cerebral ischemia, cerebral irritability and cerebral depression.
↵†† We included included intracranial hemorrhage/laceration, and injury to the CNS/PNS, scalp and skeleton.
↵‡‡ We included a combination of postpartum hemorrhage and transfusion codes.
↵§§ We included cardiac arrest, cardiac failure, myocardial infarction and pulmonary embolism.
↵¶¶ We included severe perineal lacerations (3rd/4th degree), cervical laceration, high vaginal laceration, injury to pelvic organ/joint, pelvic hematoma and extension of uterine incision.
↵*** We included sepsis, infection of obstetric surgical wound, infection of the genital tract following delivery, urinary tract infection following delivery, genitourinary tract infections following delivery, pyrexia of unknown origin following delivery and other specified puerperal infection.
↵††† Crude OR is reported because AOR was undefined owing to small numbers.