Table 1.
Summary of Article Characteristics
| Author and Year | Study Country | Study Design | Study Years | No. of Patients | Rate of Atonic PPH n (%) | Mode of Delivery |
|---|---|---|---|---|---|---|
| Bateman et al, 20101 | United States | Retrospective cohort | 1995–2004 (2004 data for risk factor analysis) | 876,641 | Atonic PPH: 20,353 (2.3) | VD CD |
| Bateman et al, 201336 | United States | Retrospective cohort | 2000–2007 | 9,750 Calcium channel blocker: 1,226 | Atonic PPH: 201 (2.1) | VD CD |
| Bekabil et al, 201537 | Ethiopia | Prospective cohort | 2012–2013 | 432 Twin: 144 | Atony: 16 (3.7) | VD CD |
| Bryant* et al, 201238 | United States | Retrospective cohort | 2005–2008 | 2,488,974 | Atonic PPH: 53,266 (2.1) | VD CD |
| Callaghan et al, 201039 | United States | Retrospective cohort | 1994–2006 | 10,481,197 | Atonic PPH: 212, 00 (2) | VD CD |
| Chalouhi* etal, 201540 | United States | Retrospective cohort | 2009–2012 | 1,062 | Atony: 87 (8.2) | VD |
| Driessen et al, 201141 | France | Prospective cohort | 2004–2006 | 146,876 | Atonic PPH: 4,550 (3.1) | VD |
| Feerasta et al, 200042 | Pakistan | Retrospective case- control | 1987–1997 | 332 Case: 112, Control: 220 | NA (case-control) | VD |
| Foley et al, 201843 | United States | Retrospective cohort | 2015 | 402 | Atony: 195 (48.5) | CD |
| Definition of Atonic PPH | Risk Factors Assessed | Covariates Adjusted For | Exclusion Criteria |
|---|---|---|---|
| ICD code | Age, mode of delivery, HDP, diabetes, uterine leiomyoma, prior CD, polyhydramnios, chorioamnionitis, precipitous delivery, long labor, medical induction of labor, multiple gestation, stillbirth, antepartum hemorrhage, retained placenta | Logistic regression included all risk factors assessed | Missing data on maternal age |
| ICD code | Calcium channel blocker administration | Age, race, ethnicity, HDP, diabetes, obesity, renal disease, leiomyomas, prior CD, placenta previa, multiple gestation, mode of delivery, induction of labor | Preterm labor or preterm delivery, migraine, arrhythmia, angina, Raynaud, exposure to multiple antihypertensives, out of hospital delivery, no diagnosis of pre-existing or gestational hypertension |
| PPH: undefined Atony: undefined | Multiple gestation | None | None |
| ICD code | Race and ethnicity (African American, Hispanic, Asian or Pacific Islander) | Induction of labor, multiple gestation, polyhydramnios, diabetes, chorioamnionitis, stillbirth, grand multiparity, preeclampsia, obesity, leiomyomas, placental abruption, placenta previa, previous CD, chronic anemia, retained placenta, prolonged labor | Race or ethnicity data missing or coded as a category not included in the study |
| ICD code | Mode of delivery | Age | None |
| PPH: EBL Atony: uterotonic† | Ethnicity (Native American) | None | Multiple gestation, preterm delivery, coagulopathy |
| PPH: EBL or Hgb drop of more than 2 g per dL | Maternal age, BMI, prior PPH, fibroma, hydramnios, parity, multiple gestation, type of onset of labor, epidural analgesia, prolonged labor, oxytocin during labor, prolonged expulsive efforts, gestational age, instrumented VD, prophylactic uterotonics, birth weight | Logistic regression included all risk factors assessed | Incomplete data, CD, PPH of etiology other than atony |
| Atony: uterotonic† or other intervention,‡ case report form to elucidate etiology | |||
| PPH: undefined Atony: undefined† | Parity, stillbirth or neonatal death, prior PPH, prior CD, HDP, antenatal anemia, multiple gestation, history of preterm labor, use of tocolytics, diabetes, polyhydramnios, amnionitis, uterine leiomyomas, induced labor, augmented labor, prolonged labor, mode of delivery, precipitous delivery, epidural, macrosomia | Logistic regression included all risk factors assessed | None |
| PPH: EBL, Hgb drop, transfusion Atony: uterotonic | Predelivery oxytocin exposure | Nulliparity, hypertension, diabetes, multiple gestation, polyhydramnios, premature rupture of membranes, preterm rupture of membranes, prolonged rupture of membranes, placenta previa, placental abruption, chorioamnionitis, macrosomia | General anesthesia, postpartum oxytocin dose not charted |
| Author and Year | Study Country | Study Design | Study Years | No. of Patients | Rate of Atonic PPH n (%) | Mode of Delivery |
|---|---|---|---|---|---|---|
| Grotegut* et al, 201144 | United States | Retrospective case- control | 2000–2004 | 108 Case: 54, control: 54 | NA (case-control) | VD CD |
| Guillaume et al, 201545 | France | Retrospective cohort | 2011–2013 | 7,810 | Atonic PPH: 202 (2.6) | VD |
| Harvey* et al, 201746 | United States | Retrospective cohort | 1995–2013 | 243,693 | Atonic PPH: 8,962 (3.7) | VD CD |
| Joseph et al, 201547 | Canada | Retrospective case- control | 1998–2009 | 138,704 Case: 6,378, control: 31,795 | NA (case-control) | VD CD |
| Kahr et al, 201848 | Switzerland | Prospective cohort | 2015–2016 | 1,487 | Atony: 71 (4.8) | VD CD |
| Kovacheva et al, 201349 | United States | Retrospective cohort | 2009 | 345 | Atony: 35 (10) | CD |
| Lao et al, 201450 | Hong Kong | Retrospective cohort | 1998–2008 | 64,886 | Atonic PPH: 1,194 (1.8) | VD CD |
| Looft et al, 201751 | Sweden | Retrospective cohort | 2008–2014 | 57,267 | Atonic PPH: 2,659 (4.6) | VD |
| Definition of Atonic PPH | Risk Factors Assessed | Covariates Adjusted For | Exclusion Criteria |
|---|---|---|---|
| PPH: ICD+chart review for transfusion | Predelivery oxytocin exposure, race, BMI, admission hematocrit, induction status, preeclampsia, magnesium therapy, chorioamnionitis | Race, BMI, admission hematocrit, induction status, magnesium treatment, chorioamnionitis | None |
| Atony: uterotonic† or other intervention‡ | |||
| PPH: EBL | Cord blood collection | Age, grand multiparity, diabetes, induction of labor, long labor, oxytocin augmentation, prophylactic postpartum oxytocin, instrumented delivery, birth weight, vaginal tearing, placental retention | Multiple gestation, gestational age less than 37 wk |
| Atony: medical team diagnosis | |||
| ICD code | Ethnicity (Native Hawaiians and Other Pacific Islanders, Asian, White) | Age, delivery type, prior CD, smoking, obesity, substance abuse, multiple gestation, multiparity, HDP, diabetes, labor induction, polyhydramnios, chorioamnionitis, placental abruption, placenta previa, prolonged labor | Non-Hawaii residents, records lacking race-ethnicity data, race-ethnicity other than Native Hawaiians and Other Pacific Islanders, Asian, or White |
| ICD code | Maternal medication use (antidepressants, aspirin, nonsteroidal antiinflammatory drugs, beta-agonists, and antihistamines), multiple pregnancies, placenta previa or abruption, polyhydramnios, prolonged labor, preeclampsia or eclampsia, epidural, labor induction, perineal trauma, uterine rupture, mode of delivery, chorioamnionitis, alcohol use disorder, liver disease, thrombocytopenia, asthma | Age, welfare status, rural vs urban residence, prior CD, alcoholism, liver disease, thrombocytopenia, multiple gestation, preeclampsia, polyhydramnios, placenta previa, placental abruption, epidural analgesia, labor induction, prolonged first stage, prolonged second stage, mode of delivery, uterine rupture, cervical laceration, severe perineal tear, chorioamnionitis | None |
| PPH: EBL or Hgb drop Atony: undefined | Blood group O | None | Gestational age less than 22 wk, primary coagulopathy or blood-clotting disorder, no informed consent, maternal age younger than 18 y |
| PPH: Difference between preoperative and postoperative hematocrit Atony: uterotonic† | Serum uric acid level | Uric acid level, use of magnesium, duration of oxytocin, polyhydramnios, oligohydramnios, chorioamnionitis, abnormal placentation, gestational age, birth weight | Multiple gestation, no serum uric acid measured within 24 hours of CD, incomplete medical records, general anesthesia, pre-existing coagulation abnormalities, hyperuricemia before pregnancy |
| PPH: EBL Atony: undefined | Maternal age | None | Maternal age younger than 20 y, gestational age less than 24 wk, multiple gestation, spontaneous miscarriage, therapeutic abortion, incomplete data |
| ICD code | Length of the second stage Length of pushing | Age, height, BMI, smoking, induction of labor, oxytocin use during first stage of labor, gestational age, birth weight | Noncephalic presentation, CD, missing data |
| Author and Year | Study Country | Study Design | Study Years | No. of Patients | Rate of Atonic PPH n (%) | Mode of Delivery |
|---|---|---|---|---|---|---|
| Lutomski et al, 201252 | Ireland | Retrospective cohort | 1999–2009 | 649,019 | Atonic PPH: 12,800 (2.0) | VD CD |
| Marshall* et al, 201753 | United States | Retrospective cohort | 2012–2013 | 1,352,691 | Atonic PPH: 31,549 (2.3) | VD CD |
| Mehrabadi et al, 201354 | Canada | Retrospective cohort | 2001–2010 | 371,193 | Atonic PPH: Total number not reported | VD CD |
| Oberg et al, 201455 | Sweden | Retrospective cohort | 1997–2009 | 538,332 women, 914,939 pregnancies | Atonic PPH: 17,818 (1.9) | VD (atonic PPH data analyzed VD only) |
| Regalia et al, 200156 | Italy | Retrospective cohort | 1995–1999 | 10,756 | Atony: 427 (4.0) | VD |
| Siddiqui* et al, 201757 | United States | Retrospective cohort | 2002–2013 | 21,898,501 | Atonic PPH: 499,189 (2.3) | VD CD |
| Tran et al, 201758 | Canada | Retrospective cohort | 2013–2015 | 490 | Atonic PPH: 80 (16) | CD |
| Vendittelli et al, 201659 | France | Prospective cohort | 2011 | 129,110 | Atonic PPH: 2,490 (1.9) | VD CD |
| Waheed et al, 201360 | Pakistan | Retrospective cohort | 2006–2009 | 8,713 | Atonic PPH: 93 (1.1) | VD CD |
| Definition of Atonic PPH | Risk Factors Assessed | Covariates Adjusted For | Exclusion Criteria |
|---|---|---|---|
| ICD code | Maternal age, hypertension, diabetes, mode of delivery, multiple gestation, large fetus, episiotomy, genital tract trauma, prolonged first stage, prolonged second stage, placental disorders, amniotic cavity infection, polyhydramnios | Age, marital status, socioeconomic status, hypertension, diabetes, mode of delivery, induction of labor, multiple gestation, macrosomia, episiotomy, genital tract trauma, prolonged labor, placenta previa, vasa previa, placental abruption, chorioamnionitis, polyhydramnios | None |
| ICD code | Race, parity | None | Incomplete data |
| ICD code | Maternal age, parity, birthweight, BMI, gestational age, smoking status, multiple gestation, mode of delivery, prior CD, epidural analgesia, induction, oxytocin augmentation, uterine rupture, third or fourth degree perineal tear, high vaginal laceration, cervical laceration, placenta previa, placental abruption, breech, transverse lie, polyhydramnios, prolonged first stage, prolonged second stage, preeclampsia, chorioamnionitis, forceps, vacuum, forceps and vacuum | Logistic regression included all risk factors assessed | Incomplete data |
| ICD code | History of PPH according to type | Year of birth, age, civil status, country of origin, chronic hypertension, diabetes, coagulopathy, leiomyomas | Multiple gestation |
| PPH: undefined | Maternal age, BMI, gestational age, parity, fetal weight, prior atony, prior CD or uterine scar, uterine leiomyomas, preeclampsia, fever in labor, hydramnios, labor induction, labor velocity of progress, use of Kristeller maneuvers, nonvertex cephalic presentation | Logistic regression included all risk factors assessed | Multiple gestation, placental risk factors for PPH, gestational age less than 35 wk, CD, incomplete data |
| Atony: undefined | |||
| ICD code | Ethnicity | None | Ethnicity other than Caucasian or Asian American and Pacific Islander |
| PPH: EBL and drop in hct | Length of the oxytocin recovery period, BMI | Preeclampsia, chorioamnionitis, morbid obesity, macrosomia, multiple gestation, polyhydramnios, oxytocin induction, dose and duration of oxytocin augmentation | Any mode of delivery other than intrapartum CD for labor arrest, women not receiving 2h or more of oxytocin augmentation during labor, gestational age less than 37 or more than 41 wk, PPH cause other than atony, incomplete data, general anesthesia |
| Atony: uterotonic† or other intervention‡ | |||
| PPH: EBL | Mode of delivery | None | None |
| Atony: undefined | |||
| PPH: EBL or change in vital signs | Mode of delivery | None | None |
| Atony: medical team diagnosis, uterine massage, uterotonic† |
| Author and Year | Study Country | Study Design | Study Years | No. of Patients | Rate of Atonic PPH n (%) | Mode of Delivery |
|---|---|---|---|---|---|---|
| Wetta* et al, 201361 | United States | Secondary analysis of randomized controlled trial | 2008–2010 | 1,798 | Atony: 118 (6.6) | VD |
| Definition of Atonic PPH | Risk Factors Assessed | Covariates Adjusted For | Exclusion Criteria |
|---|---|---|---|
| PPH: EBL Atony: medical team diagnosis | Age, oxytocin dose, BMI, ethnicity, race, augmentation, induction, birthweight, parity, preeclampsia, magnesium use, twin gestation, chorioamnionitis, hydramnios, amnioinfusion, epidural anesthesia, breastfeeding, artificial rupture of membranes | Logistic regression included all risk factors assessed | Gestational age less than 24 wk, CD, fetal demise, pulmonary edema, coagulopathy, cardiomyopathy |
PPH, postpartum hemorrhage; VD, vaginal delivery; CD, cesarean delivery; ICD, International Classification of Diseases; HDP, hypertensive disorders of pregnancy; EBL, estimated blood loss; Hgb, hemoglobin; BMI, body mass index; hct, hematocrit; NA, not applicable.
*
Article evaluates race or ethnicity as risk factor for atonic postpartum hemorrhage. Additional information regarding classifications of race or ethnicity used, who classified patients, whether options were defined by participants or investigators, reasons race or ethnicity were assessed, missing data, and “other” categories is presented in Appendix 4, http://links.lww.com/AOG/C163.
†
Uterotonic administration was in addition to standard oxytocin therapy.
‡
“Other interventions” included the use of a Bakri balloon, uterine massage, uterine artery embolization, or surgical interventions.