
USCA1 Opinion

	




                            UNITED STATES COURT OF APPEALS                            UNITED STATES COURT OF APPEALS                                FOR THE FIRST CIRCUIT                                FOR THE FIRST CIRCUIT                              _________________________          No. 96-1894                               RAFAELA CORT S-IRIZARRY,                                Plaintiff, Appellant,                                          v.                       CORPORACI N INSULAR DE SEGUROS, ET AL.,                                Defendants, Appellees.                              _________________________                     APPEAL FROM THE UNITED STATES DISTRICT COURT                           FOR THE DISTRICT OF PUERTO RICO                   [Hon. Salvador E. Casellas, U.S. District Judge]                                               ___________________                              _________________________                                        Before                               Torruella, Chief Judge,                                          ___________                            Coffin, Senior Circuit Judge,                                    ____________________                              and Selya, Circuit Judge.                                         _____________                              _________________________               David Efron, with  whom Kevin  G. Little was  on brief,  for               ___________             ________________          appellant.               Elisa  M. Figueroa  B ez, with  whom  Law Offices  of Sigrid               ________________________                              ______          Lopez Gonzalez was on brief, for appellees.          ______________                              _________________________                                    April 16, 1997                              _________________________                    SELYA,  Circuit  Judge.    Plaintiff-appellant  Rafaela                    SELYA,  Circuit  Judge.                            ______________          Cort s-Irizarry  (Cort s), suing  on behalf  of her  minor child,          Rafael  Jos  Mu iz  Cort s (Jos ),  challenges an  order granting          summary judgment to  Corporaci n Insular de Seguros (CIS) and its          insured, Juan Ram n Gonz lez Aristud (Dr. Gonz lez), in a medical          malpractice action.  See Irizarry v. CIS, 928 F.  Supp. 141, 147-                               ___ ________    ___          48 (D.P.R. 1996).  We vacate the order and remand for trial.          I.  BACKGROUND          I.  BACKGROUND                    Although the  accepted summary judgment  protocol calls          for  us to cast the facts in  the light most complimentary to the          plaintiff's position, consistent with record support,  see, e.g.,                                                                 ___  ____          Garside v. Osco  Drug, Inc., 895 F.2d 46, 48  (1st Cir. 1990), we          _______    ________________          temper that protocol here to the extent that we set off, as point          and counterpoint,  conflicting evidence where the  clash helps to          illuminate pertinent legal issues.  For simplicity's sake we omit          any further reference to CIS and treat its insured as  if he were          the sole defendant.                    Dr.  Gonz lez,  a  specialist in  obstetrics,  provided          prenatal care to Cort s after she  became pregnant with Jos .  On          December 15, 1979, Cort s  related to Dr. Gonz lez that  her last          menstrual  cycle prior  to  conception began  on  November 2  and          lasted  only two days.   The length of  her immediately preceding          menses was three days,  and her periods typically had  lasted two          or three days  during the  year prior to  her current  pregnancy.          Based  on this  data, Dr.  Gonz lez calculated  Cort s' estimated          delivery date (EDD) to be  August 9, 1980.  He delivered  Jos  by                                          2          cesarean section on  July 30,  1980.  The  newborn weighed  eight          pounds,  eight and  three-quarter  ounces (two  pounds more  than          Cort s' first child) and exhibited no fetal distress.                    According to the  defendant's computations, Cort s  was          in her  thirty-ninth  week of  pregnancy when  the baby  arrived.          This  calculation forms  the nub  of the  case.   The plaintiff's          theory  is that Dr. Gonz lez misfigured the baby's fetal age and,          consequently, allowed the pregnancy  to continue beyond forty-two          weeks,  thus bringing  into play  a risk  factor known  as "post-          datism" or "post-maturity."   A  post-dated fetus is  at risk  of          oxygen deprivation during its extended stay in the mother's womb,          and brain damage is a predictable result.  While Jos , at  birth,          displayed   no  detectable   symptoms  suggesting   a  post-dated          delivery,  the   circumstances  of  the  delivery  revealed  some          indications  of potential  perinatal difficulties;  for instance,          the cesarean  section took  twenty-one minutes (roughly  twice as          long as  the norm), and,  on one  view of the  proof, a  tracheal          catheter was used to intubate the newborn.1                    Time resolved  these mixed signals.   Jos  showed signs          of neurologic abnormality at three  months and was diagnosed with                                        ____________________               1Other contemporaneous indicators were  inscrutable.  On the          one hand, Jos  had a relatively high Apgar score.  An Apgar score          is comprised of five components:  heart rate, respiratory effort,          muscle  tone,  reflex irritability,  and  color.   It  usually is          compiled by the anesthesiologist at one minute after the delivery          and again  at the  five-minute mark.   A  low score  is generally          thought to have predictive value in determining brain damage.  On          the other  hand, testing at  birth revealed  a somewhat  elevated          serum  bilirubin   level  (which  could   indicate  an  incipient          metabolic problem).                                          3          impaired motor  development and hearing loss  at fourteen months.          His condition worsened as the years passed.  As an adolescent, he          was  diagnosed  as   severely  brain   damaged,  epileptic,   and          profoundly deaf.   At that  juncture, Cort s, then  a citizen  of          Florida,  sued Dr.  Gonz lez  in Puerto  Rico's federal  district          court, see 28 U.S.C.   1332(a) (diversity jurisdiction), alleging                 ___          that the physician's negligence caused her son's infirmities.                    Cort s'  case rests  primarily on  the opinions  of two          experts.  An  obstetrician, Dr. Bernard Nathanson,  opined that a          competent obstetrician, rather than  relying upon a reported two-          day menstrual  period to  calculate a  gravid woman's  EDD, would          have launched a more detailed gynecologic investigation.  Had Dr.          Gonz lez done so,  the witness stated,  he would have  discovered          that Cort s'  actual  EDD was  July 9,  1980, and  he would  have          recognized that  a substantial risk of post-datism arose when her          pregnancy extended past the EDD (a risk which he presumably could          have negated  by performing  the cesarean section  earlier).   In          reaching  these conclusions, Dr.  Nathanson stressed  the unusual          brevity  of the  reported period  (especially as  contrasted with          Cort s' previous menses) and Dr. Gonz lez' failure to confirm the          EDD by  performing various tests  which the  witness stated  were          available in  1979-1980 (e.g., a B-scan  ultrasound examination).          In Dr. Nathanson's opinion, the pregnancy was post-dated, and the          defendant's  failure to  realize  it and  take corrective  action          violated the prevailing standard of care.                    Dr. Nathanson  also  disputed Dr.  Gonz lez'  assertion                                          4          that  he in fact performed a manual pelvic examination at Cort s'          initial   appointment  and   subsequently  measured   her  uterus          throughout  her pregnancy to corroborate the  EDD.  Dr. Nathanson          saw no evidence that  these steps had been taken.   Moreover, Dr.          Gonz lez'  office  record did  not  mention  either the  periodic          uterine measurements  or their results.  Although some of Cort s'          prenatal charts apparently had  been lost,  Dr.  Nathanson stated          that  these data  "are  so  vital that  they  should  be in  [Dr.          Gonz lez'] record in any case had he done them."                    The plaintiff's second expert, Dr.  Allan Hausknecht, a          neurologist,  diagnosed Jos  as  suffering from  Lennox Gasteault          Syndrome (LGS).  This neurological condition is caused roughly          fifty percent of  the time by  perinatal brain damage  (resulting          from  a lack of  sufficient oxygen to  the fetal  brain).  Doctor          Hausknecht  stated  that,  in  his  experience,  this  percentage          increases sharply when, as  in this instance, no evidence  of any          other known cause exists.  Noting that the gradual development of          Jos 's condition  was characteristic of a  post-mature fetus, Dr.          Hausknecht rendered an opinion  that Jos 's brain damage resulted          from the  post-datism which Dr.  Nathanson had identified.   This          opinion was bolstered in some degree by Dr. Nathanson's statement          that, while some  post-dated infants will show immediate signs of          placental senescence, such as  meconium-stained amniotic fluid or          peeling of the skin  (Jos  had neither), many others  will appear          asymptomatic at birth yet manifest the  effects of post-datism at          a later time.                                          5                    To  be   sure,  the  plaintiff's  evidence   was  hotly          contested.  The defendant   claimed that he  had figured the  EDD          accurately  and that many of the tests suggested by Dr. Nathanson          were  unnecessary, or impracticable, or  both.  He also presented          experts  who   offered  an  alternative   theory  of   causation:          intrauterine  cytomegalovirus (CMV)  infection, a  rare condition          which  occurs in  0.2 to  2.2 percent  of all  live births.   The          results  of blood tests performed on Jos  at age fifteen revealed          previous or  latent CMV infection,  but did not  indicate whether          the   infection  had  been  contracted  in  utero.    This  is  a          significant omission  because, while infants who  suffer from CMV          may  be  asymptomatic  at  birth and  thereafter  develop  mental          retardation  or deafness, CMV can  be transmitted in various ways          and affects most individuals during their lifetimes.          II.  THE SUMMARY JUDGMENT STANDARD          II.  THE SUMMARY JUDGMENT STANDARD                    A court  may grant summary judgment  "if the pleadings,          depositions, answers to interrogatories, and  admissions on file,          together  with  the affidavits,  if any,  show  that there  is no          genuine issue as  to any material fact and that  the moving party          is  entitled to a judgment as a matter  of law."  Fed. R. Civ. P.          56(c).  We  have expounded this standard and its particulars in a          symphony  of cases,  see, e.g.,  McCarthy v.  Northwest Airlines,                               ___  ____   ________     ___________________          Inc., 56 F.3d 313, 315 (1st Cir. 1995) (collecting cases), and we          ____          refrain from  rehearsing this  jurisprudential chorus here.   For          our  purposes,  it  suffices   briefly  to  describe  the  rule's          operation.                                          6                    The  objective of  summary judgment  "is to  pierce the          boilerplate  of the  pleadings and  assay the  parties' proof  in          order to determine whether trial is actually required."  Wynne v.                                                                   _____          Tufts Univ. Sch. of Med., 976 F.2d 791,  794 (1st Cir. 1992).  To          ________________________          defeat  a motion for  summary judgment, the  nonmoving party must          demonstrate  the existence  of  a trialworthy  issue  as to  some          material  fact.  See Coyne v. Taber  Partners I, 53 F.3d 454, 457                           ___ _____    _________________          (1st Cir.  1995).  A fact  is "material" if it  potentially could          affect the  suit's outcome.   See  Garside, 895 F.2d  at 48.   An                                        ___  _______          issue  concerning  such  a  fact  is  "genuine"  if  a reasonable          factfinder, examining  the  evidence and  drawing all  reasonable          inferences helpful to the party resisting summary judgment, could          resolve  the  dispute  in  that  party's  favor.    See  National                                                              ___  ________          Amusements, Inc. v. Town of Dedham, 43 F.3d  731, 735 (1st Cir.),          ________________    ______________          cert. denied, 115 S. Ct. 2247 (1995).          _____ ______                    Exercising de novo review,  see Coyne, 53 F.3d  at 457,                                                ___ _____          we  hold that the record in  this case presents triable issues as          to whether  Dr. Gonz lez violated his  duty of care,  and, if so,          whether his  actions caused  Jos 's injuries.   Consequently, the          district  court   erred  in   granting  the  motion   for  brevis                                                                     ______          disposition.          III.  ANALYSIS          III.  ANALYSIS                    We  first survey  the junction  where summary  judgment          principles  and  the  standards  governing the  admissibility  of          expert scientific evidence intersect.  We then evaluate the lower          court's ruling.                                          7                                          A.                                          A.                                          __                    The  defendant  asserts on  appeal  that  the entry  of          judgment should  be affirmed because  the district court  had the          power  to exclude  the  plaintiff's expert  evidence pursuant  to          Daubert  v.  Merrell  Dow  Pharmaceuticals, Inc.,  509  U.S.  579          _______      ___________________________________          (1993),  and that,  without such  evidence, the plaintiff  has no          case.  Cort s parries this thrust by contending that Daubert does                                                               _______          not  apply at  the  summary  judgment  stage.    The  truth  lies          somewhere in between.                    The  Daubert  Court  formulated  a regime  for  use  in                         _______          ascertaining  the  admissibility  of  expert  scientific evidence          under  Fed. R. Evid. 702.2   This regime  contemplates that trial          judges  will perform a gatekeeping function, determining "whether          the  reasoning  or  methodology  underlying   [proffered  expert]          testimony  is  scientifically  valid  and  .  .  .  whether  that          reasoning  or methodology properly can be applied to the facts in          issue."   Daubert,  509  U.S. at  592-93;  see United  States  v.                    _______                          ___ ______________          Sepulveda, 15  F.3d 1161, 1183  (1st Cir. 1993)  (discussing this          _________          function).                                        ____________________               2The rule stipulates:                         If   scientific,  technical,   or  other                    specialized knowledge will  assist the  trier                    of  fact to  understand  the  evidence or  to                    determine   a  fact   in  issue,   a  witness                    qualified as  an expert by  knowledge, skill,                    experience,   training,   or  eduction,   may                    testify thereto in the  form of an opinion or                    otherwise.          Fed. R. Evid. 702.                                          8                    The plaintiff  posits that Daubert is  strictly a time-                                               _______          of-trial phenomenon.  She  is wrong.  The Daubert regime can play                                                    _______          a role during the summary judgment phase of civil litigation.  If          proffered expert testimony fails to cross Daubert's threshold for                                                    _______          admissibility, a  district court  may exclude that  evidence from          consideration when  passing upon  a motion for  summary judgment.          See Cavallo  v. Star Enter., 100 F.3d 1150, 1159 (4th Cir. 1996),          ___ _______     ___________          petition for cert. filed,  65 U.S.L.W. 2399 (U.S. Mar.  19, 1997)          ________ ___ _____ _____          (No. 96-1493); Peitzmeier v. Hennessy  Indus., Inc., 97 F.3d 293,                         __________    ______________________          297-99  (8th Cir.  1996), petition for  cert. filed,  65 U.S.L.W.                                    ________ ___  _____ _____          3539  (U.S. Jan.  29, 1997)  (No. 96-1212);  Claar v.  Burlington                                                       _____     __________          N.R.R.,  29 F.3d 499, 502-05 (9th Cir. 1994); Porter v. Whitehall          ______                                        ______    _________          Lab., Inc., 9 F.3d 607, 612, 616-17 (7th Cir. 1993).          __________                    The  fact that Daubert  can be used  in connection with                                   _______          summary judgment motions  does not  mean that it  should be  used          profligately.  A  trial setting  normally will  provide the  best          operating environment for the triage which Daubert demands.  Voir                                                     _______           ____          dire  is  an extremely  helpful  device  in evaluating  proffered          ____          expert testimony, see Sepulveda,  15 F.3d at 1184 n.15,  and this                            ___ _________          device is not readily available in the course of summary judgment          proceedings.     Moreover,  given  the  complex  factual  inquiry          required by Daubert, courts  will be hard-pressed in all  but the                      _______          most clearcut cases to gauge the reliability of expert proof on a          truncated record.   Because the summary judgment process does not          conform well to the discipline that  Daubert imposes, the Daubert                                               _______              _______          regime should be employed only with great care and circumspection                                          9          at the summary judgment stage.                    We  conclude, therefore,  that  at  the junction  where          Daubert  intersects  with summary  judgment practice,  Daubert is          _______                                                _______          accessible, but courts must be cautious   except when defects are          obvious  on the  face of  a proffer    not  to exclude  debatable          scientific  evidence  without  affording  the  proponent  of  the          evidence adequate opportunity to  defend its admissibility.3  See                                                                        ___          Margaret A. Berger, Procedural Paradigms for Applying the Daubert                              _____________________________________________          Test, 78 Minn. L. Rev. 1345, 1379-80, 1381 (1994).          ____                    Having  rejected  the plaintiff's  broadcast contention          that Daubert can never be used at  the summary judgment stage, we               _______          turn  to  the  defendant's  case-specific  argument  that Daubert                                                                    _______          necessitates  the  exclusion  of  the opinions  advanced  by  the          plaintiff's experts.  This asseveration suffers from a very basic          shortcoming:   the  defendant never  asked the district  court to          exclude this evidence from  consideration, and the district court          made no effort to do  so on its own initiative.   If trial courts          should be slow to  employ Daubert at the summary  judgment stage,                                    _______          appellate courts should  be even  more hesitant to  head in  that                                        ____________________               3Though such an opportunity is most easily afforded at trial          or in  a trial-like  setting, courts have  displayed considerable          ingenuity in devising  ways in  which an adequate  record can  be          developed  so  as  to  permit  Daubert  rulings  to  be  made  in                                         _______          conjunction with motions for summary  judgment.  See, e.g., Brown                                                           ___  ____  _____          v. SEPTA  (In re Paoli R.R.  Yard PCB Litig.), 35  F.3d 717, 736,             _____   _________________________________          739  (3d Cir. 1994) (discussing use of in limine hearings), cert.                                                 __ ______            _____          denied, 115 S. Ct. 1253 (1995); Claar, 29 F.3d at 502 (discussing          ______                          _____          district court's  technique of ordering experts  to submit serial          affidavits  explaining the  reasoning and  methodology underlying          their  conclusions).   We  do  not  in  any  way  disparage  such          practices; we merely  warn that  the game sometimes  will not  be          worth the candle.                                          10          direction where there has been no development of the issue below.          After all, the bifurcated  inquiry into reliability and relevance          which Daubert  requires is best  performed by  trial judges  who,                _______          unlike appellate judges, have a broad array of tools which can be          brought to bear on  the evaluation of expert testimony.4   Hence,          we can  envision few, if  any, cases in which  an appellate court          would venture to superimpose  a Daubert ruling on a  cold, poorly                                          _______          developed  record when  neither the  parties  nor the  nisi prius          court has had a meaningful opportunity to mull the question.                    This case falls squarely into the maw of these  general          principles.   The  defendant, notwithstanding  the animadversions          that he spouts on  appeal, never asked  in the district court  to          strike or otherwise defenestrate the statements of Drs. Nathanson          and/or Hausknecht.   The district court's  rescript neither cites          Daubert nor  purposes to exclude the expert evidence submitted on          _______          the plaintiff's behalf.   And, moreover, the record as  it stands          is wholly inadequate to  permit a reasoned Daubert determination.                                                     _______          For these reasons, we decline the defendant's odd invitation that          we start from  scratch and  undertake a Daubert  analysis in  the                                                  _______                                        ____________________               4It  is for this reason,  coupled with the  special coign of          vantage which trial  courts enjoy, that we have afforded district          judges  broad   discretion  in  determining   whether  particular          scientific testimony is or is not admissible at trial.  See Hoult                                                                  ___ _____          v. Hoult, 57  F.3d 1, 5  (1st Cir. 1995);  Sepulveda, 15 F.3d  at             _____                                   _________          1183.   In this vein,  we note that  the Supreme Court  soon will          resolve a disagreement  among the circuits as  to the appropriate          standard for reviewing  such decisions.   See  Joiner v.  General                                                    ___  ______     _______          Elec.  Co., 78  F.3d  524 (11th  Cir.  1996), cert.  granted,  65          __________                                    _____  _______          U.S.L.W.  3619 (U.S. Mar. 17, 1997) (No. 96-188).  That standard-          of-review question need not concern us today.                                          11          context  of this appeal.5   This means,  of course, that  we must          consider  the  entire  record,  including the  opinions  of  Drs.          Nathanson and Hausknecht, as we ponder the merits of the district          court's dispositive ruling.                                          B.                                          B.                                          __                    In this  diversity suit, the substantive  law of Puerto          Rico controls.   See  Erie  R.R. v.  Tompkins,  304 U.S.  64,  78                           ___  __________     ________          (1938); Rolon-Alvarado v. Municipality of San Juan, 1 F.3d 74, 77                  ______________    ________________________          (1st Cir. 1993).   The Puerto  Rico Civil Code  states that  "[a]          person who by an act or omission causes damage to another through          fault  or negligence  shall be  obliged to  repair the  damage so          done."    P.R.  Laws Ann.  tit.  31,    5141  (1991).  Under this          proviso, three elements  comprise a prima  facie case of  medical          malpractice; a plaintiff must establish (1) the  duty owed (i.e.,          the minimum standard of professional knowledge and skill required          in  the   relevant  circumstances),   (2)  an  act   or  omission          transgressing  that  duty,  and  (3) a  sufficient  causal  nexus                                        ____________________               5In all events, we  note that the two  grounds urged by  the          defendant   in   support   of   his   exclusionary   request  are          inappropriate.    First, Dr.  Gonz lez  asserts  that his  expert          evidence is more persuasive than the plaintiff's.  His insistence          that this circumstance warrants exclusion of the competing expert          evidence contradicts  fundamental principles of  summary judgment          practice.   See, e.g., Greenburg v. Puerto Rico Maritime Shipping                      ___  ____  _________    _____________________________          Auth.,  835  F.2d 932,  936 (1st  Cir. 1987).   Daubert  does not          _____                                           _______          reverse these principles.   See Daubert, 509 U.S. at  595-96; see                                      ___ _______                       ___          also  Ambrosini v. Labarraque,  101 F.3d  129, 140-41  (D.C. Cir.          ____  _________    __________          1996), petition for cert.  filed, ___ U.S.L.W. ___ (U.S.  Apr. 1,                 ________ ___ _____  _____          1997) (No. 96-1552).  Second, he claims that the testimony of the          plaintiff's witnesses, if allowed, would  be confusing.  The fact          that particular expert evidence might tend  to confuse or mislead          a  jury can constitute grounds  for exclusion of  the evidence at          trial, see  Fed. R. Evid. 403, but it is not directly relevant to                 ___          a Daubert analysis.  See Daubert, 509 U.S. at 595-96.            _______            ___ _______                                          12          between the breach and the claimed harm.  See Lama  v. Borras, 16                                                    ___ ____     ______          F.3d 473,  478 (1st Cir. 1994); Rolon-Alvarado, 1 F.3d at 77.  On                                          ______________          whole-record  review,  we conclude  that  the  plaintiff produced          sufficient evidence to establish a genuine factual controversy as          to each element.                    1.   Duty and Breach.   In this  case, the  elements of                    1.   Duty and Breach.                         _______________          duty and breach are  inextricably intertwined.  Thus,  we address          them in the ensemble.                    Puerto  Rico  holds  health  care  professionals  to  a          national standard of  care.  See Oliveros v. Abreu, 101 P.R. Dec.                                       ___ ________    _____          209, 226-27, translated in 1 P.R. Sup.  Ct. Off'l Trans. 293, 313                       __________ __          (1973).  Accordingly,  a health care provider has  "a duty to use          the same degree of expertise as could reasonably be expected of a          typically competent practitioner in the identical specialty under          the  same  or  similar   circumstances,  regardless  of  regional          variations  in  professional acumen  or level  of care."   Rolon-                                                                     ______          Alvarado, 1 F.3d at 77-78.  Nevertheless, because Puerto Rico law          ________          presumes  that physicians exercise  reasonable care,  a plaintiff          bent  on  establishing a  breach of  a  physician's duty  of care          ordinarily  must  adduce expert  testimony  to  limn the  minimum          acceptable standard and confirm the defendant doctor's failure to          meet it.  See id. at 78.                    ___ ___                    Cort s'  proffer  is  sufficient  to  this  end.    Dr.          Nathanson,  a  specialist  in the  same  field  as  Dr. Gonz lez,          clearly delineated the  standard of care  and identified what  he          believed  to  be Dr.  Gonz lez' departures  from  it.   He stated                                          13          categorically that an "average gynecologist" would not rely on  a          reported  two-day  menstrual period     unusually  short even  if          relatively common  to that particular  individual   and  that the          failure  to perform corroborating  tests then  available violated          "the  prevailing  medical standard."    For  purposes of  summary          judgment, affiants and witnesses need not be precise to the point          of  pedantry.  Thus, we  treat Dr. Nathanson's  references to the          "average gynecologist"  and to "the prevailing  medical standard"          as meaning the  national standard of care.  Cf.  Lama, 16 F.3d at                                                      ___  ____          479 n.7.                    The district court advanced three principal  grounds in          support of its  conclusion that these issues    duty and breach            could  be resolved against the  plaintiff at the summary judgment          stage, notwithstanding Dr. Nathanson's  opinion evidence.  All of          these grounds lack persuasive force.                    First,   the  court  observed  that  Cort s'  menstrual          periods  had lasted  "an  average of  two  to three  days,"  and,          accordingly,  "a two-day  period  was not  abnormal or  unusually          short  for  her."   Irizarry,  928  F. Supp.  at  146.   But  Dr.                              ________          Nathanson's  testimony supported  the opposite  conclusion; thus,          whether the menses was  abnormal and whether it triggered  a duty          to inquire further became questions of fact not properly resolved          on  summary  judgment.    See,  e.g.,  Greenburg v.  Puerto  Rico                                    ___   ____   _________     ____________          Maritime Shipping Auth., 835 F.2d 932, 936 (1st Cir. 1987).          _______________________                    Second, the court determined that, because Dr. Gonz lez          measured  the  uterus  periodically  throughout   the  pregnancy,                                          14          yielding results consistent with  the EDD on which he  relied, he          had no  reason to  suspect an  earlier date  of conception or  to          order any additional tests.   See Irizarry, 928 F. Supp. at  146.                                        ___ ________          While Dr. Gonz lez so testified, the court erred in treating that          testimony as conclusive.  When Dr. Gonz lez'  and Dr. Nathanson's          assertions are juxtaposed, the  net result is a factual  issue as          to  whether  the defendant  made  the measurements,  and,  if so,          whether this procedure satisfied the applicable standard of care.                    Third, the  court damned  Dr. Nathanson's  opinion with          the faintest of  praise, characterizing it  as nothing more  than          one doctor's  assertion that he  would have acted  differently in          identical  circumstances  than  did another,  and,  consequently,          denying  it effect in the summary judgment  calculus.  See id. at                                                                 ___ ___          147.  We accept the  court's premise that a mere disagreement  in          medical  judgment, without more, does not prove duty or breach in          a  medical malpractice case brought  under Puerto Rico  law.  See                                                                        ___          Rolon-Alvarado,  1 F.3d  at  78.    But  we  reject  the  court's          ______________          conclusion; Dr. Nathanson's declarations, read in context, amount          to  a  satisfactory statement  of the  standard  of care  and the          defendant's deviation from it which, if credited by a jury, could          support  a finding  for the  plaintiff on  these elements  of her          cause of action.   And in the absence of a  Daubert determination                                                      _______          excluding the Nathanson evidence as scientifically untenable, the          trial court was not at liberty on summary judgment to ignore that          evidence merely because it deemed other evidence more credible.                    2.   Causation.  Notwithstanding proof of both duty and                    2.   Causation.                         _________                                          15          breach,  a  plaintiff  also  must  offer  competent  evidence  of          causation in a  medical malpractice case.   See Rolon-Alvarado, 1                                                      ___ ______________          F.3d at 77.  The lower court found the plaintiff's submissions on          this element wanting.   See Irizarry,  928 F. Supp.  at 147.   We                                  ___ ________          demur.                    A medical  malpractice plaintiff can   and often does            establish causation through expert testimony.   See Lama, 16 F.3d                                                          ___ ____          at  478.   Cort s  took that  route.   Dr.  Nathanson offered  an          opinion to a reasonable degree  of medical certainty that Cort s'          EDD was actually  July 9, not August  9, and that  this one-month          discrepancy had  dire consequences.  If  accepted, this testimony          meant  that Dr.  Gonz lez  did not  perform the  cesarean section          until the forty-third week of a post-dated pregnancy.                    Relatedly,  Dr. Hausknecht diagnosed  Jos  as suffering          from LGS,  which, in the  absence of any  genetic or other  known          explanation, is generally thought to be caused by perinatal brain          damage.  It is undisputed that the adverse effects of post-datism          include oxygen  deprivation, and thus  can lead to  brain damage.          Finding no evidence  of any hereditary  etiology and observing  a          pathology consistent with post-datism, Dr. Hausknecht opined that          Jos 's  cerebral damage  probably was  caused by  the post-datism          which  Dr.  Nathanson identified.    Both  physicians also  noted          likely indications of complications  at birth, and these findings          buttress  the  plaintiff's   theory  of   causation.6     Drawing                                        ____________________               6Dr.  Nathanson  dwelled  on  the unusual  duration  of  the          cesarean section and the  apparent use of a tracheal  catheter to          resuscitate the infant at birth.  Dr. Hausknecht noted that there                                          16          reasonable inferences  from this evidence, a  rational jury could          find that Dr.  Gonz lez' negligent reliance upon  a reported two-          day  menstrual period  and  his eschewal  of further  (available)          tests  caused  a  post-dated  pregnancy,  the  effects  of  which          included perinatal  brain damage  which manifested itself  in the          form of LGS.                    Of  course,  the   defendant's  experts  debunked   the          plaintiff's  proof and offered an alternative causal theory   the          presence  of a  CMV infection    which  the district  court found          "more  compelling."   Irizarry, 928  F. Supp.  at 147.   But such                                ________          comparisons are invidious at the summary judgment stage.  Even at          trial, a plaintiff in a medical malpractice suit need not prove a          causal  connection with  mathematical accuracy nor  eliminate all          other  possible  causes  of  damage.    See   Cruz  Rodriguez  v.                                                  ___   _______________          Corporaci n de  Servicios del Centro  M dico, 113 P.R.  Dec. 719,          ____________________________________________          744,  translated in  13 P.R.  Sup. Ct.  Off'l Trans.  931, 960-61                __________ __          (1983).  Legal rules  of this sort acquire added  significance on          summary  judgment because Rule  56 "contemplates  an abecedarian,          almost one  dimensional, exercise geared  to determining  whether          the nonmovant's  most favorable evidence and  the most flattering          inferences which can reasonably be drawn therefrom are sufficient          to  create any authentic question  of material fact."  Greenburg,                                                                 _________          835 F.2d at 936.                    In this  case, the defendant's evidence on the issue of                                        ____________________          had been an  abnormal bilirubin  level at birth  and expressed  a          belief  that this might  evince a metabolic  problem damaging the          brain.                                          17          causation, as compelling as it might have seemed, did not warrant          the  entry of  summary judgment.   The  plaintiff articulated  an          alternative  theory of  causation  and backed  it up  with expert          testimony  as to  the causal  nexuses between  LGS  and perinatal          damage,  and between perinatal  damage and  post-datism.   At the          same time, she cast doubt on the defendant's theory of causation,          establishing the low incidence  of intrauterine CMV infection and          suggesting  an alternate  origin of  any  CMV detected  in Jos 's          system (related  to a  history of  sexual molestation  at school,          thereby  opening up  the possibility that  any CMV  infection was          sexually  transmitted).    This  evidence sufficed  to  create  a          trialworthy issue vis- -vis the element of causation.  See Coyne,                                                                 ___ _____          53 F.3d at 460 (explaining that "when the facts support plausible          but  conflicting inferences on a  pivotal issue in  the case, the          judge may  not choose  between those  inferences  at the  summary          judgment stage"); see also United States  v. Kayne, 90 F.3d 7, 12                            ___ ____ _____________     _____          (1st  Cir. 1996)  (stating that  disagreements among  experts are          "properly the subject of searching cross-examination"  at trial),          cert. denied, 117 S. Ct. 681 (1997).          _____ ______          III.  CONCLUSION          III.  CONCLUSION                    We need go no further.  Scrutinizing the  entire record          in the  light most  congenial to  the plaintiff, rational  jurors          could find all the  elements of medical malpractice.   Though the          plaintiff's  evidence may  appear  thin to  some, it  establishes          factual disagreements  as to  which reasonable minds  may differ.          No  more is exigible.  See Greenburg, 835 F.2d at 936 (explaining                                 ___ _________                                          18          that the  ground rules associated with  summary judgment practice          "admit of no room for credibility determinations, no room for the          measured  weighing  of conflicting  evidence  such  as the  trial          process entails, no  room for  the judge to  superimpose his  own          ideas  of probability  and likelihood  (no matter  how reasonable          those  ideas  may be)  upon the  carapace  of the  cold record").          Right or  wrong, the plaintiff is entitled to present her case to          a jury.                    The order granting summary  judgment is vacated and the                    The order granting summary  judgment is vacated and the                    _______________________________________________________          case is remanded for trial.  Costs to appellant.          case is remanded for trial.  Costs to appellant.          __________________________   __________________                                          19
