2024
The association of higher offspring early‐childhood weight gain with prepregnancy metabolic and bariatric surgery
Hilaire M, Babcock A, White G, Masson C, Salem R, Reddy U, Gallagher D, LeDuc C, Thaker V. The association of higher offspring early‐childhood weight gain with prepregnancy metabolic and bariatric surgery. Obesity 2024, 32: 2012-2023. PMID: 39497631, DOI: 10.1002/oby.24166.Peer-Reviewed Original ResearchConceptsOffspring growth trajectoriesBariatric surgeryHypertensive disorders of pregnancyWorld Health Organization Child Growth StandardsRoux-en-Y gastric bypassWeight gainHigher BMI z-scoreEarly-life weight gainNon-MB groupDisorders of pregnancyGestational diabetes mellitusGestational weight gainLow birth weightBMI z-scoreChild Growth StandardsScore-matched controlsPrepregnancy BMIGestational outcomesHypertensive disordersSleeve gastrectomyGastric bypassBirth weightPrepregnancyDiabetes mellitusGrowth standardsDesign, rationale and protocol for Glycemic Observation and Metabolic Outcomes in Mothers and Offspring (GO MOMs): an observational cohort study
Group T, Scholtens D, LeBlanc E, Vesco K, Amy D, Bays K, Massimino S, Robinson S, Schell K, Walters G, Hillier T, Oshiro C, Cordero S, Howick C, Kim L, Martinez Y, Pishchalenko O, Wastlova V, Zork N, Mourad M, Lonier J, Reddy U, Acevedo J, Castillo J, Gomez M, Peguero B, Facco F, Feghali M, Bocan H, Stramowski S, Powe C, Edlow A, Barth W, Nathan D, Azevedo R, Baez A, Iroajanma C, Larkin M, Maya J, Michalopoulos C, Neamonitaki N, Thangthaeng N, Yee L, Lowe W, Grobman W, Szmuilowicz E, Aguirre A, Guevara E, Mallett G, Matos S, Tyagi S, Spadola A, Catalano P, Azimirad A, Werner E, Rouse D, Malloy M, Parra F, Sherr J, Merriam A, Bitterman S, Considine E, Leventhal J, Perley L, Rink L, Steffen A, Thompson B, Zgorski M, Steffes M, Arends V, Killeen A, Siddique J, Bustamante P, Cheung Y, Freeze C, Grott T, Kuang A, Tull M, Linder B. Design, rationale and protocol for Glycemic Observation and Metabolic Outcomes in Mothers and Offspring (GO MOMs): an observational cohort study. BMJ Open 2024, 14: e084216. PMID: 38851233, PMCID: PMC11163666, DOI: 10.1136/bmjopen-2024-084216.Peer-Reviewed Original ResearchConceptsLarge-for-gestational-age birth weightMetabolic outcomesLarge-for-gestational-ageDiagnosis of gestational diabetesOral glucose tolerance testAdverse pregnancy outcomesVanderbilt University Institutional Review BoardCourse of pregnancyObservational cohort studyGlucose tolerance testNational Institute of DiabetesDigestive and Kidney DiseasesGDM treatmentWeeks gestationDetect such abnormalitiesPerinatal outcomesGDM screeningInstitutional review boardGestational diabetesFirst-trimesterPregnancy outcomesEarly pregnancyGlucose abnormalitiesBirth weightPregnant adultsAdverse Pregnancy Outcomes and Predicted 30-Year Risk of Maternal Cardiovascular Disease 2–7 Years After Delivery
Venkatesh K, Khan S, Yee L, Wu J, McNeil R, Greenland P, Chung J, Levine L, Simhan H, Catov J, Scifres C, Reddy U, Pemberton V, Saade G, Merz C, Grobman W, Mothers-to-Be A. Adverse Pregnancy Outcomes and Predicted 30-Year Risk of Maternal Cardiovascular Disease 2–7 Years After Delivery. Obstetrics And Gynecology 2024, 143: 775-784. PMID: 38574364, PMCID: PMC11098696, DOI: 10.1097/aog.0000000000005569.Peer-Reviewed Original ResearchConceptsRisk of atherosclerotic CVDAtherosclerotic CVD riskAdverse pregnancy outcomesHypertensive disorders of pregnancyAtherosclerotic CVDCVD riskDisorders of pregnancyPregnancy outcomesHypertensive disordersPreterm birthModified Poisson modelsFramingham risk scoreRisk of CVDRisk of atherosclerotic cardiovascular diseaseMagnitude of riskAbsolute riskAtherosclerotic cardiovascular diseaseSecondary analysisLongitudinal cohortRisk scoreGestational ageGreater riskBaseline covariatesCardiovascular diseaseDisease 2
2023
Cannabis Exposure and Adverse Pregnancy Outcomes Related to Placental Function
Metz T, Allshouse A, McMillin G, Greene T, Chung J, Grobman W, Haas D, Mercer B, Parry S, Reddy U, Saade G, Simhan H, Silver R. Cannabis Exposure and Adverse Pregnancy Outcomes Related to Placental Function. JAMA 2023, 330: 2191-2199. PMID: 38085313, PMCID: PMC10716715, DOI: 10.1001/jama.2023.21146.Peer-Reviewed Original ResearchConceptsPrimary composite outcomeAdverse pregnancy outcomesComposite outcomeFirst trimesterCannabis exposurePregnancy outcomesCannabis usePlacental functionPropensity score-weighted analysisNulliparous Pregnancy Outcomes StudyOngoing exposureMaternal cannabis useUrine cotinine assayUrine samplesMedical record abstractionPregnancy outcome dataGestational-age birthsBody mass indexGestational age windowsPregnancy Outcomes StudyUS medical centersOngoing cannabis useAdjudication of outcomesMaternal cannabisHypertensive disordersSodium intake and the development of hypertensive disorders of pregnancy
Bank T, Grasch J, Chung J, Mercer B, McNeil R, Parry S, Saade G, Shanks A, Silver R, Simhan H, Yee L, Reddy U, Grobman W, Frey H. Sodium intake and the development of hypertensive disorders of pregnancy. American Journal Of Obstetrics & Gynecology MFM 2023, 5: 101166. PMID: 37741626, DOI: 10.1016/j.ajogmf.2023.101166.Peer-Reviewed Original ResearchConceptsHypertensive disordersHigh sodium intakeSodium intakeChronic hypertensionNonpregnant populationLow platelet count syndromeNeonatal intensive care unitNulliparous Pregnancy Outcomes StudyElevated liver enzymesGestational age neonatesFood frequency questionnaireLow sodium intakeIncidence risk ratioIntensive care unitWeeks of gestationPregnancy Outcomes StudyLack of associationChi-square testGestational hypertensionNeonatal outcomesNonpregnant stateSodium restrictionFrequency questionnairePreterm birthSingleton pregnanciesCervical Pessary for Prevention of Preterm Birth in Individuals With a Short Cervix
Hoffman M, Clifton R, Biggio J, Saade G, Ugwu L, Longo M, Bousleiman S, Clark K, Grobman W, Frey H, Chauhan S, Dugoff L, Manuck T, Chien E, Rouse D, Simhan H, Esplin M, Macones G, Bickus M, Facco F, Tita A, Grant J, Casey B, Harris S, Harper L, Dunn D, Longo S, Hendricks M, Lata-Arias K, Costantine M, Bartholomew A, Cline D, Harper S, Ward C, Gardner N, Brindle S, Weigand S, McKenna D, Snow E, Fennig K, Habli M, Lambers D, McClellan M, Metz T, Sowles A, Varner M, Hill K, Morby V, Meadows C, Allard D, Werner E, Rousseau J, Milano J, Pettker C, Leventhal J, Gyamfi-Bannerman C, Wapner R, Carmona V, Firman B, Vanneman A, Palomares K, Beche I, Skupski D, Chan-Akeley R, Salazar A, Pacheco L, McCoy L, Saad A, Jain S, Omere C, Clifford C, McDonnold M, Chien E, Dalton W, Polito L, Milluzi C, Kushner K, Maile A, Bell J, Hackney D, Ortiz F, Timlin S, Goodnight W, Manuck T, Beamon C, Nun H, Eichelberger K, Moore A, Hughes B, Ferrara J, Grobman W, Mallett G, Stein L, Miller E, Plunkett B, Kearns K, Palatnik A, Malone T, Parry S, Pizzi C, Craig J, Filipczak A, Thom E, Doherty L, Hubbard A, Erikson P, Pinto T, Marcharchand P, Reddy U, Miodovnik M, Archer S. Cervical Pessary for Prevention of Preterm Birth in Individuals With a Short Cervix. JAMA 2023, 330: 340-348. PMID: 37490086, PMCID: PMC10369212, DOI: 10.1001/jama.2023.10812.Peer-Reviewed Original ResearchConceptsCervical pessaryUsual carePreterm birthShort cervixVaginal progesteroneCervical lengthSingleton pregnanciesFetal deathPrimary outcomeInfant deathPrior spontaneous preterm birthTransvaginal ultrasound cervical lengthCervical pessary placementWeeks 0 daysSpontaneous preterm birthUltrasound cervical lengthWeeks 6 daysThird interim analysisNeonatal/infant mortalityPreterm deliverySingleton gestationsBaseline characteristicsUltrasound evidencePessary placementTransvaginal ultrasoundAssociation of maternal body mass index with success and outcomes of attempted operative vaginal delivery
Grasch J, Venkatesh K, Grobman W, Silver R, Saade G, Mercer B, Yee L, Scifres C, Parry S, Simhan H, Reddy U, Frey H. Association of maternal body mass index with success and outcomes of attempted operative vaginal delivery. American Journal Of Obstetrics & Gynecology MFM 2023, 5: 101081. PMID: 37422004, DOI: 10.1016/j.ajogmf.2023.101081.Peer-Reviewed Original ResearchMeSH KeywordsBody Mass IndexCesarean SectionDelivery, ObstetricFemaleHumansInfant, NewbornPregnancyPregnancy OutcomeProspective StudiesConceptsMaternal body mass indexBody mass indexOperative vaginal deliveryVaginal delivery attemptComposite maternal morbidityComposite neonatal morbidityVaginal deliveryMass indexNeonatal morbidityCesarean deliveryMaternal morbidityAdverse outcomesSecond-stage cesarean deliveryBody mass index groupsBody mass index categoriesNulliparous Pregnancy Outcomes StudyNonanomalous singleton pregnanciesNeonatal adverse outcomesMultivariable logistic regressionPregnancy Outcomes StudyNulliparous individualsDose-dependent mannerSecondary outcomesSingleton pregnanciesPrimary outcomeFetal growth restriction and small for gestational age as predictors of neonatal morbidity: which growth nomogram to use?
Leon-Martinez D, Lundsberg L, Culhane J, Zhang J, Son M, Reddy U. Fetal growth restriction and small for gestational age as predictors of neonatal morbidity: which growth nomogram to use? American Journal Of Obstetrics And Gynecology 2023, 229: 678.e1-678.e16. PMID: 37348779, DOI: 10.1016/j.ajog.2023.06.035.Peer-Reviewed Original ResearchConceptsNeonatal composite outcomeComposite outcomeFetal growth restrictionGestational ageFetal weightWeeks of gestationPositive likelihood ratioGrowth restrictionNonanomalous singleton pregnanciesPoor neonatal outcomeRetrospective cohort studySingle academic centerWeeks of deliveryDays of deliveryFetal growth referencesElectronic medical recordsProportion of fetusesLikelihood ratioNeonatal morbidityNeonatal outcomesPerinatal outcomesCohort studySingleton pregnanciesNeonatal dataMedical recordsMaternal and Delivery Characteristics and Self-Reported Perceived Control During Labor
Mallett G, Hill K, Doherty L, Grobman W, Reddy U, Tita A, Silver R, Rice M, El-Sayed Y, Wapner R, Rouse D, Saade G, Thorp J, Chauhan S, Costantine M, Chien E, Casey B, Srinivas S, Swamy G, Simhan H, Macones G. Maternal and Delivery Characteristics and Self-Reported Perceived Control During Labor. Obstetrics And Gynecology 2023, 142: 117-124. PMID: 37290106, PMCID: PMC10330140, DOI: 10.1097/aog.0000000000005230.Peer-Reviewed Original ResearchMeSH KeywordsDelivery, ObstetricFemaleHumansInfantInfant, NewbornLabor PainLabor, InducedLabor, ObstetricPregnancySelf ReportConceptsBody mass indexWeeks of gestationLabor Agentry ScaleScale scoreLabor painPrivate health insuranceDelivery characteristicsLabor pain scoresPrevious pregnancy lossSpontaneous vaginal deliverySevere neonatal complicationsHealth insuranceMode of deliveryFinal multivariable modelMultivariable linear regressionSelf-administered questionnaireSelf-reported raceNeonatal complicationsExpectant managementPain scoresLabor inductionNonprivate insuranceOperative deliveryCesarean deliveryVaginal deliveryOutcomes of induction vs prelabor cesarean delivery at <33 weeks for hypertensive disorders of pregnancy
Bushman E, Grobman W, Bailit J, Reddy U, Wapner R, Varner M, Thorp J, Caritis S, Prasad M, Saade G, Sorokin Y, Rouse D, Blackwell S, Tolosa J, Network E. Outcomes of induction vs prelabor cesarean delivery at <33 weeks for hypertensive disorders of pregnancy. American Journal Of Obstetrics & Gynecology MFM 2023, 5: 101032. PMID: 37244639, PMCID: PMC10521213, DOI: 10.1016/j.ajogmf.2023.101032.Peer-Reviewed Original ResearchConceptsPrelabor cesarean deliveryHypertensive disordersInduction of laborCesarean deliveryLabor inductionNeonatal morbidityInduction groupMedian durationVaginal deliveryWeeks' gestationSecondary analysisAdverse composite outcomeComposite maternal morbidityOutcome of inductionPreterm hypertensive disordersHalf of patientsCesarean delivery groupLength of inductionOptimal delivery approachMaternal morbidityComposite outcomeFetal malpresentationMultiple gestationsPreterm birthSecondary outcomesPlacental lesions associated with stillbirth by gestational age, according to feature importance: Results from the stillbirth collaborative research network
Cersonsky T, Cersonsky R, Saade G, Silver R, Reddy U, Goldenberg R, Dudley D, Pinar H. Placental lesions associated with stillbirth by gestational age, according to feature importance: Results from the stillbirth collaborative research network. Placenta 2023, 137: 59-64. PMID: 37080046, PMCID: PMC10192128, DOI: 10.1016/j.placenta.2023.04.005.Peer-Reviewed Original ResearchMeSH KeywordsFemaleGestational AgeHumansInfant, NewbornPlacentaPlacenta DiseasesPregnancyPregnancy ComplicationsStillbirthConceptsStillbirth Collaborative Research NetworkGestational agePlacental lesionsDifferent gestational agesCollaborative research networksResearch NetworkTerm stillbirthFetal mortalityPlacental featuresHistologic changesStillbirthLesionsWeeksStandard protocolPlacentaFurther investigationAgePrincipal covariatesPrevious studiesGestationMortalityShort-term neonatal outcomes of pregnancies complicated by maternal obesity
Dinsmoor M, Ugwu L, Bailit J, Reddy U, Wapner R, Varner M, Thorp J, Caritis S, Prasad M, Tita A, Saade G, Sorokin Y, Rouse D, Blackwell S, Tolosa J, Network E. Short-term neonatal outcomes of pregnancies complicated by maternal obesity. American Journal Of Obstetrics & Gynecology MFM 2023, 5: 100874. PMID: 36690180, PMCID: PMC10065915, DOI: 10.1016/j.ajogmf.2023.100874.Peer-Reviewed Original ResearchMeSH KeywordsFemaleHumansInfant, NewbornObesity, MaternalObesity, MorbidParityPerinatal DeathPregnancyPremature BirthConceptsComposite neonatal morbidityNeonatal outcomesBody mass indexWeeks of gestationMaternal obesityNeonatal morbidityMorbid obesityMass indexReference groupIntraventricular hemorrhage grade 3Short-term neonatal outcomesCohort of deliveriesComposite neonatal outcomeSuper morbid obesityHypoxic-ischemic encephalopathyPrevious cesarean deliveryRespiratory distress syndromeChronic hypertensionPreterm deliveryBaseline characteristicsCesarean deliveryComposite outcomeMaternal heightMaternal preeclampsiaObese patients
2022
Association of a Mediterranean Diet Pattern With Adverse Pregnancy Outcomes Among US Women
Makarem N, Chau K, Miller E, Gyamfi-Bannerman C, Tous I, Booker W, Catov J, Haas D, Grobman W, Levine L, McNeil R, Merz C, Reddy U, Wapner R, Wong M, Bello N. Association of a Mediterranean Diet Pattern With Adverse Pregnancy Outcomes Among US Women. JAMA Network Open 2022, 5: e2248165. PMID: 36547978, PMCID: PMC9857221, DOI: 10.1001/jamanetworkopen.2022.48165.Peer-Reviewed Original ResearchConceptsAdverse pregnancy outcomesMediterranean diet patternTime of conceptionPregnancy outcomesDiet patternLower oddsAMED scoresGestational diabetesCohort studyUS womenLower riskRisk of APOsPrepregnancy body mass indexCardiovascular disease risk factorsSemiquantitative food frequency questionnaireAlternate Mediterranean diet scoreNulliparous Pregnancy Outcomes StudyLowest AMED scoresGestational age infantsDisease risk factorsDose-response associationFood frequency questionnaireMediterranean diet scoreBody mass indexCause of morbidityMechanism of neonatal hypoglycemia after late preterm steroids: are fetal metabolic effects responsible?
Battarbee AN, Sandoval GJ, Gyamfi-Bannerman C, Blackwell SC, Tita ATN, Reddy UM, Jain L. Mechanism of neonatal hypoglycemia after late preterm steroids: are fetal metabolic effects responsible? American Journal Of Obstetrics And Gynecology 2022, 227: 347-349.e4. PMID: 35364060, PMCID: PMC9308675, DOI: 10.1016/j.ajog.2022.03.045.Peer-Reviewed Original ResearchHypertension in pregnancy and adverse outcomes among low‐risk nulliparous women expectantly managed at or after 39 weeks: a secondary analysis of a randomised controlled trial
Bartal M, Premkumar A, Rice M, Reddy U, Tita ATN, Silver RM, El‐Sayed Y, Wapner R, Rouse DJ, Saade GR, Thorp JM, Costantine M, Chien EK, Casey BM, Srinivas SK, Swamy GK, Simhan HN, Health H. Hypertension in pregnancy and adverse outcomes among low‐risk nulliparous women expectantly managed at or after 39 weeks: a secondary analysis of a randomised controlled trial. BJOG An International Journal Of Obstetrics & Gynaecology 2022, 129: 1396-1403. PMID: 34927787, PMCID: PMC9207156, DOI: 10.1111/1471-0528.17059.Peer-Reviewed Original ResearchConceptsAdverse maternal outcomesLow-risk nulliparous womenHypertensive disordersMaternal outcomesSecondary outcomesNulliparous womenAdverse outcomesComposite adverse maternal outcomeIntensive care unit admissionSecondary analysisCare unit admissionSevere neonatal complicationsWeeks of gestationMode of deliveryNulliparous individualsMaternal compositeNeonatal complicationsPerinatal compositePostpartum infectionUnit admissionCaesarean deliveryExpectant managementPlacental abruptionVenous thromboembolismGestational age
2021
Chronic hypertension, perinatal mortality and the impact of preterm delivery: a population‐based study
Grover S, Brandt J, Reddy U, Ananth C. Chronic hypertension, perinatal mortality and the impact of preterm delivery: a population‐based study. BJOG An International Journal Of Obstetrics & Gynaecology 2021, 129: 572-579. PMID: 34536318, PMCID: PMC9214277, DOI: 10.1111/1471-0528.16932.Peer-Reviewed Original ResearchConceptsPerinatal mortality rateChronic hypertensionEarly term deliveryPreterm deliveryPerinatal mortalityMortality rateTerm deliverySingleton birthsCausal mediation analysisMaternal chronic hypertensionElevated blood pressureModifiable risk factorsPopulation-based studyWeeks of gestationLate-term gestationCross-sectional analysisNormotensive pregnanciesPreterm birthBlood pressureTerm gestationPerinatal deathRisk factorsHypertensionMAIN OUTCOMEMortalityOutcomes in Twins Compared With Singletons Subsequent to Preterm Prelabor Rupture of Membranes
Bartal M, Ugwu LG, Grobman WA, Bailit JL, Reddy UM, Wapner RJ, Varner MW, Thorp JM, Caritis SN, Prasad M, Tita ATN, Saade GR, Rouse DJ. Outcomes in Twins Compared With Singletons Subsequent to Preterm Prelabor Rupture of Membranes. Obstetrics And Gynecology 2021, 138: 725-731. PMID: 34619719, PMCID: PMC8542618, DOI: 10.1097/aog.0000000000004561.Peer-Reviewed Original ResearchMeSH KeywordsAdultChorioamnionitisCohort StudiesEndometritisEnterocolitis, NecrotizingFemaleFetal Membranes, Premature RuptureGestational AgeHumansInfant, NewbornInfant, PrematureOutcome Assessment, Health CarePerinatal MortalityPregnancyPregnancy OutcomePregnancy, TwinPremature BirthSepsisVenous ThromboembolismWound InfectionYoung AdultConceptsComposite maternal morbidityPreterm prelabor ruptureWeeks of gestationNeonatal morbidityPreterm PROMSingleton gestationsMaternal morbidityPrelabor ruptureTwin gestationsOdds ratioComposite major neonatal morbidityComposite neonatal morbidityMajor neonatal morbidityMedian gestational ageMedian latency periodMajor fetal anomaliesAdjusted odds ratioCoprimary outcomesObstetric cohortNeonatal outcomesTwin neonatesGestational agePotential confoundersFetal anomaliesMorbidityMaternal and Neonatal Outcomes in Nulliparous Participants Undergoing Labor Induction by Cervical Ripening Method
Andrikopoulou M, Bushman E, Rice M, Grobman W, Reddy U, Silver R, El-Sayed Y, Rouse D, Saade G, Thorp J, Chauhan S, Costantine M, Chien E, Casey B, Srinivas S, Swamy G, Simhan H. Maternal and Neonatal Outcomes in Nulliparous Participants Undergoing Labor Induction by Cervical Ripening Method. American Journal Of Perinatology 2021, 40: 1061-1070. PMID: 34352922, PMCID: PMC8817048, DOI: 10.1055/s-0041-1732379.Peer-Reviewed Original ResearchMeSH KeywordsCervical RipeningDinoprostoneFemaleHumansInfant, NewbornLabor, InducedOxytocicsOxytocinPregnancyConceptsAdverse neonatal outcomesCervical ripeningNeonatal outcomesLabor inductionNulliparous participantsComposite outcomeAdverse maternal outcomesCervical ripening methodsMaternal composite outcomeNeonatal composite outcomeLow-risk womenLength of laborConcurrent oxytocinCoprimary outcomesNeonatal compositeExpectant managementMaternal outcomesCesarean deliverySecondary outcomesFetal demisePatient characteristicsMultivariable analysisCervical dilationLower riskSecondary analysis
2019
Duration of Operative Vaginal Delivery and Adverse Obstetric Outcomes
Miller E, Lai Y, Bailit J, Reddy U, Wapner R, Varner M, Thorp J, Leveno K, Caritis S, Prasad M, Tita A, Saade G, Sorokin Y, Rouse D, Blackwell S, Tolosa J. Duration of Operative Vaginal Delivery and Adverse Obstetric Outcomes. American Journal Of Perinatology 2019, 37: 503-510. PMID: 30895577, PMCID: PMC6754310, DOI: 10.1055/s-0039-1683439.Peer-Reviewed Original ResearchConceptsComposite adverse neonatal outcomeAdverse neonatal outcomesOperative vaginal deliveryNeonatal outcomesVaginal deliveryMulticenter observational cohortAdverse obstetric outcomesSevere perineal lacerationsObstetric outcomesPerinatal outcomesObservational cohortPerineal lacerationsPrimary cohortForceps applicationPotential confoundersSecondary analysisStrong associationOutcomesWomenCohortDurationDeliveryLacerationConfoundersForceps
2018
Potentially Preventable Stillbirth in a Diverse U.S. Cohort
Page JM, Thorsten V, Reddy UM, Dudley DJ, Hogue CJR, Saade GR, Pinar H, Parker CB, Conway D, Stoll BJ, Coustan D, Bukowski R, Varner MW, Goldenberg RL, Gibbins K, Silver RM. Potentially Preventable Stillbirth in a Diverse U.S. Cohort. Obstetrics And Gynecology 2018, 131: 336-343. PMID: 29324601, PMCID: PMC5785410, DOI: 10.1097/aog.0000000000002421.Peer-Reviewed Original ResearchConceptsStillbirth Collaborative Research NetworkPreventable stillbirthsPlacental insufficiencyHypertensive disordersMultiple gestationsMedical complicationsPopulation-based case-control studyDiverse U.S. cohortSpontaneous preterm birthMedical record abstractionWeeks of gestationCases of stillbirthCase-control studyCollaborative research networksResearch NetworkStillbirth reductionPreterm laborPreterm birthPlacental pathologyRecord abstractionNonanomalous fetusesMaternal interviewsPostmortem examinationU.S. cohortStillbirth