Court Opinion

ID: 2687597
Source: CourtListenerOpinion
Date Created: 2014-07-31 21:42:33.82363+00
Date Added: 2024-06-11T12:13:56.345356
License: Public Domain

IN THE SUPREME COURT OF IOWA
                               No. 12–0302

                            Filed May 9, 2014

ALAN ASHER and LARYSA ASHER, as Parents and Next Friends of
ALEXANDRA ASHER, a minor, and ALAN ASHER and LARYSA ASHER,
Individually,

      Appellees,

vs.

OB-GYN SPECIALISTS, P.C., and ANTHONY A. ONUIGBO, M.D.,

      Appellants.

      Appeal from the Iowa District Court for Black Hawk County,

Thomas N. Bower, Judge.

      Defendants in a medical negligence action appeal a jury verdict.

AFFIRMED.

      David L. Baker, Cedar Rapids, and James A. Gerk and Christine L.

Conover of Simmons Perrine Moyer Berman PLC, Cedar Rapids, for

appellants.

      Mark McCormick of Belin McCormick, P.C., Des Moines, and

H. Daniel Holm Jr., Max E. Kirk, and Eashaan Vajpeyi of Ball, Kirk &

Holm, P.C., Waterloo, for appellees.
                                               2

APPEL, Justice.

        In this professional negligence action, we consider whether the

district court committed reversible error by providing the jury with a

causation instruction based upon the Restatement (Second) of Torts

rather than an instruction based upon the Restatement (Third) of Torts,

as adopted by this court in Thompson v. Kaczinski, 774 N.W.2d 829, 839

(Iowa 2009). We also consider whether substantial evidence supported

submission of two specifications of negligence to the jury, one based on a

physician’s use of a vacuum extractor during the delivery of a baby and
another based on the physician’s failure to keep adequate documentation

of the labor and delivery process.

        For the reasons expressed below, we conclude that although the

district court should have submitted a causation instruction based upon

the Restatement (Third) of Torts and Thompson, the error was harmless

under the facts and circumstances of this case.               We further conclude

substantial evidence supported submission of the two challenged

specifications of negligence to the jury.

        I. Factual Background and Proceedings.

        A. Overview of Proceedings.                  Larysa Asher was admitted to

Covenant Medical Center (Covenant) in Waterloo for the delivery of a

baby.     The physician providing delivery services at Covenant was

Dr. Anthony A. Onuigbo.               Unfortunately, the baby was born with a

brachial plexus injury and broken clavicle. Asher and her husband filed

an action individually and as parents and next friends of their minor

child, asserting Onuigbo was negligent in connection with the delivery of

the baby.1

        1We   will refer to the Ashers jointly as “Asher.”
                                      3

        After substantial discovery and a two-week trial, the district court

instructed the jury.    Instruction No. 12 asserted Asher had to prove

Onuigbo was negligent in at least one of the following ways:

              A. In failing to document the progress of descent
                  during the second stage of Larysa Asher’s labor;

              B. Using a [vacuum extractor] to assist in the delivery
                 of [the baby];

              C. In failing to perform a cesarean section on Larysa
                  Asher for the purpose of delivering [the baby];

              D. In failing to recognize and diagnose [the baby’s]
                 shoulder dystocia;

              E. In failing to perform proper maneuvers to deliver
                  [the baby] after she developed shoulder dystocia;

              F. By applying excessive lateral and/or rotational
                 traction to [the baby’s] head in an effort to deliver
                 her.

Instruction No. 12 further informed the jury it could award damages only

if it found Onuigbo’s negligence was a proximate cause of the damage.

Onuigbo objected to the instruction, arguing Asher failed to present

substantial evidence of a causal link between any failure to document

and the alleged harm or the use of the vacuum extractor and the alleged
harm.

        The district court also instructed the parties on causation.

Instruction No. 13 instructed the jury as follows:

             The conduct of a party is a proximate cause of damage
        when it is a substantial factor in producing damages and
        when the damage would not have happened except for the
        conduct.

               “Substantial” means the party’s conduct has such an
        effect in producing damage as to lead a reasonable person to
        regard it as a cause.
                                     4

Onuigbo objected to Instruction No. 13 on the ground that while it would

have been proper in the past, Thompson substantially altered the law of

causation and the instruction did not reflect the current state of the law.

      The jury found in favor of Asher and awarded substantial

damages. After the district court denied Onuigbo’s posttrial motions, he

appealed.   On appeal, Onuigbo claims Instruction No. 13 inaccurately

reflected the current state of the law in light of Thompson and, as a

result, the judgment must be vacated and the case remanded for a new

trial. Onuigbo also claims there was insufficient evidence to support a
finding of negligence based upon the failure to document the progress of

the fetus’s descent through the birth canal during the second stage of

labor or the use of the vacuum extractor to assist in the delivery.

Onuigbo argues that because the jury returned a general verdict and it is

not possible to determine whether the verdict was based upon a valid

theory of negligence, the verdict cannot stand.

      B. Overview of Trial Record. Because we are reviewing whether

substantial evidence supported submission of certain instructions to the

jury, we view the evidence in the light most favorable to the party

advocating submission of the instructions. See Hoekstra v. Farm Bureau

Mut. Ins. Co., 382 N.W.2d 100, 107–08 (Iowa 1986). Viewing the facts in

the light most favorable to Asher, a reasonable jury could have found the

facts as follows.

      Larysa began experiencing contractions on the morning of

November 7, 2006.     Her husband drove her to Covenant, where they

arrived at approximately 7:05 a.m. At 10:00 p.m., Larysa’s medical chart

indicates she was completely dilated, meaning the first stage of her labor
was complete. Though there had been some documentation of the fetus’s

station, or position, in the birth canal prior to this time, as recently as
                                       5

8:00 p.m., there was no documentation of the fetus’s station at 10:00

p.m. From this point until the birth of the baby at 2:26 a.m., there was

no further documentation of the fetus’s station, although either Onuigbo

or another member of the medical team performed vaginal exams at

11:54 p.m. and 1:47 a.m.

      Larysa experienced a protraction disorder during the first and

second stages of labor. A protraction disorder occurs when the fetus’s

descent through the birth canal proceeds at an unusually slow rate. The

severe protraction of the second stage of labor indicated the fetus was
having trouble moving past the pelvic bone. During the second stage of

labor, Onuigbo breached the standard of care by not performing enough

vaginal examinations and by not documenting the progress of the labor

and the station of the fetus in the birth canal.

      The protracted labor and lack of adequate progress posed a risk of

harm to the baby. Onuigbo did not discuss the risk of harm with his

patient. Onuigbo then used a vacuum extractor to help draw the baby

into position for delivery.    The baby’s shoulder became lodged against

Larysa’s pubic bone, a condition known as shoulder dystocia. Instead of

performing maneuvers to free the lodged shoulder, Onuigbo applied

lateral traction, causing injury to the baby’s brachial plexus nerves.

      II. Standard of Review.

      “We review a claim that the district court gave an instruction not

supported by the evidence for correction of errors at law.”      Pavone v.

Kirke, 801 N.W.2d 477, 494 (Iowa 2011). “ ‘We review the related claim

that the trial court should have given the defendant’s requested

instructions for an abuse of discretion.’ ”    State v. Marin, 788 N.W.2d
833, 836 (Iowa 2010) (quoting Summy v. City of Des Moines, 708 N.W.2d
333, 340 (Iowa 2006)).        The trial court commits legal error “when it
                                     6

materially misstates the law.” Anderson v. Webster City Cmty. Sch. Dist.,

620 N.W.2d 263, 265 (Iowa 2000).         An error in giving an instruction

“does not warrant reversal unless the error is prejudicial to a party.”

Herbst v. State, 616 N.W.2d 582, 585 (Iowa 2000).          “Errors in jury

instructions are presumed prejudicial unless ‘the record affirmatively

establishes there was no prejudice.’ ” State v. Murray, 796 N.W.2d 907,

908 (Iowa 2011) (quoting State v. Hanes, 790 N.W.2d 545, 551 (Iowa

2010)). “ ‘When the error is not of constitutional magnitude, the test of

prejudice is whether it sufficiently appears that the rights of the
complaining party have been injuriously affected or that the party has

suffered a miscarriage of justice.’ ” Marin, 788 N.W.2d at 836 (quoting

State v. Gansz, 376 N.W.2d 887, 891 (Iowa 1985)).

      When a jury returns a verdict based upon a specification of

negligence, there must be substantial evidence to support the verdict.

See Vachon v. Broadlawns Med. Found., 490 N.W.2d 820, 822 (Iowa

1992) (“The submission of instructions upon issues that have no support

in the evidence is error.”); see also City of Cedar Falls v. Cedar Falls

Cmty. Sch. Dist., 617 N.W.2d 11, 16 (Iowa 2000) (finding substantial

evidence supported findings of negligence under multiple specifications).

Evidence is substantial enough to support a specification of negligence

where “a reasonable mind would accept it as adequate to reach a

conclusion.”   Bride v. Heckart, 556 N.W.2d 449, 452 (Iowa 1996).        In

considering whether the      instruction is supported by substantial

evidence, we give the evidence the most favorable construction it will

bear in favor of supporting the instruction. See Hoekstra, 382 N.W.2d at

107–08. Where the district court submits to the jury a specification of
negligence not supported by the evidence and the jury returns a general

verdict, reversal is required. Nichols v. Westfield Indus., Ltd., 380 N.W.2d
7

392, 396–97 (Iowa 1985); Childers v. McGee, 306 N.W.2d 778, 780 (Iowa

1981).

      III. Discussion of the Causation Instruction.

      A. Positions of the Parties.       Onuigbo maintains Instruction

No. 13 was erroneous and should not have been given.           Onuigbo’s

argument is rooted in Thompson. In Thompson, we noted the formulation

of proximate cause by way of a substantial-factor test in prior law “ha[d]

been the source of significant uncertainty and confusion.” 774 N.W.2d

at 836.   As a result, we adopted the standard as articulated by the
drafters of the Restatement (Third) of Torts.    Id. at 839.   Under the

Restatement (Third) of Torts, factual cause and scope of liability (a more

nuanced term for what was previously known as proximate cause) are

addressed separately. Id. at 837; see also Restatement (Third) of Torts:

Liab. for Physical & Emotional Harm, ch. 6, Special Note on Proximate

Cause, at 492 (2010) [hereinafter Restatement (Third)].          Compare

Restatement (Third), ch. 5, at 346–491 (factual cause), with id. ch. 6, at

492–604 (scope of liability). As a result, Onuigbo contends the district

court misstated the law when it gave a causation instruction based on

the substantial-factor test. Onuigbo notes the district court believed the

approach to scope of liability and factual cause of the Restatement

(Third) did not apply in a medical malpractice case, a belief Onuigbo

argues is incorrect.

      Asher recognizes this court adopted the approach to causation of

the Restatement (Third) in Thompson and agrees with Onuigbo that it

should apply in medical malpractice cases.      Asher further agrees that

under the Restatement (Third), causation analysis is now separated into
scope of liability and factual cause.    Asher maintains, however, the

question of whether certain harm is within an alleged tortfeasor’s scope
                                      8

of liability is often established as a matter of law, thus avoiding the need

to instruct the jury on scope of liability.      Asher cites comment a to

section 29 of the Restatement (Third), which provides:

      Ordinarily, the plaintiff’s harm is self-evidently within the
      defendant’s scope of liability and requires no further
      attention. Thus, scope of liability functions as a limitation
      on liability in a select group of cases, operating more like an
      affirmative defense, although formally it is not one.

Restatement (Third) § 29 cmt. a, at 493–94.         Asher also points to a

committee comment to instruction 700.3A of the Iowa State Bar

Association Civil Jury Instructions on scope of liability, which states:

             In most cases, scope of liability will not be in dispute
      or will be adjudicated by the court on a dispositive motion.
      This instruction should be given only if under the facts of the
      particular case scope of liability is a question for the jury.

Iowa State Bar Ass’n, Iowa Civil Jury Instruction 700.3A cmt. (2012).

      Asher maintains that in this case, scope of liability was not in

dispute and required no further attention. She notes that in order to

show the alleged harm was within the scope of liability, the harm must

arise from “the same general types of danger that the defendant should

have taken reasonable steps . . . to avoid.” See id. 700.3A. Asher further

notes that in making the determination of whether the harm was within

the scope of liability, the fact finder should consider whether “repetition

of [the] defendant’s conduct makes it more likely harm of the type

plaintiff claims to have suffered would happen to another.” Id.

      Applying these standards, Asher argues Onuigbo’s scope of liability

was established as a matter of law. She notes the harm to the baby, a

brachial   plexus   injury,   is   among   the   harms   that   result   from

mismanagement of the delivery of a baby. Asher further asserts that if
the acts she alleged were to be repeated—such as failure to document
                                     9

progress or use of the vacuum extractor—it is more likely the same harm

that occurred in this case would happen to other babies. Because scope

of liability under the Restatement (Third) was established as a matter of

law, Asher contends, the giving of an erroneous proximate cause

instruction was not a material error.

      In the alternative, Asher argues that while Instruction No. 13 may

have been erroneously given, any error was harmless. Asher maintains

the substantial-factor instruction imposed an additional barrier to

liability no longer sanctioned by Iowa law. In other words, Asher claims
the erroneous instruction was harmless because a jury that found the

substantial-factor test in Instruction No. 13 was satisfied would have

necessarily found that the harm was within Onuigbo’s scope of liability

under the Restatement (Third).

      B. Analysis.     In Thompson, this court considered the law of

causation in a negligence action involving physical harm.       High winds

blew a disassembled trampoline across a yard and into a roadway, where

it came to rest. 774 N.W.2d at 831.      Later that day, a motorist who

encountered the trampoline in the road was injured when he swerved to

avoid it and crashed into a ditch. Id. at 831–32.

      We began by noting that a trial court instructing a jury on

causation in accordance with the Restatement (Second) of Torts would

instruct the jury that “ ‘[t]he actor’s negligent conduct is a legal cause of

harm to another if (a) his conduct is a substantial factor in bringing

about the harm, and (b) there is no rule of law relieving the actor from

liability.’ ” Id. at 836 (quoting Restatement (Second) of Torts § 431, at

428 (1965) [hereinafter Restatement (Second)]).        We then noted this
traditional approach caused “significant uncertainty and confusion.” Id.;

see also Gerst v. Marshall, 549 N.W.2d 810, 816–18 (Iowa 1996)
                                     10

(chronicling this court’s inconsistent approach to proximate causation).

To eliminate the uncertainty and confusion, we observed that the

drafters of the Restatement (Third) addressed factual cause and what

was formerly known as proximate cause (and now called scope of

liability) separately. Thompson, 774 N.W.2d at 837.

      Although sometimes labeled “medical malpractice” actions, a claim

that a professional has failed to meet the applicable standard of care is

essentially a negligence cause of action. See Kemin Indus., Inc. v. KPMG

Peat Markwick LLP, 578 N.W.2d 212, 221 (Iowa 1998). Nothing in the
Restatement (Third) suggests its approach to factual causation and scope

of liability does not apply to a claim of medical negligence.            The

introduction to the Restatement (Third) indicates it generally covers

negligence actions.   See Restatement (Third) Intro., at 1. Restatement

(Third) section 26, comment n discusses the applicability of the loss of

chance doctrine in medical malpractice actions. Id. § 26 cmt. n, at 356–

57. Restatement (Third) section 35, comment a uses an example of a

negligent medical professional in discussing the medical professional’s

scope of liability. Id. § 35 cmt. a, illus. 1, at 592–93. Further, we can

discern no reason to except medical negligence actions from the factual

cause and scope of liability approach of the Restatement (Third). As a

result, we conclude the district court erred in submitting Instruction

No. 13 to the jury because it instructed the jury based upon the

substantial-factor approach of the Restatement (Second).

      Nonetheless, we conclude any error in submitting the instruction

was harmless.     We agree with Asher that in most cases the alleged

tortfeasor’s scope of liability will not be an issue and this case provides a
good example of that. A brachial plexus injury is the kind of harm one

might expect to be more likely to occur if a delivering physician, like
                                       11

Onuigbo, was negligent in the manner alleged by Asher.              But a

reasonable jury could find repetition of Onuigbo’s conduct makes it more

likely the type of harm Asher claims to have suffered would happen to

another. Thus, Onuigbo’s scope of liability was established as a matter

of law. Of course, whether the alleged negligence is a factual cause of

the harm remains an open question for the jury to decide.

       In any event, the error in this case was not prejudicial.        In

Thompson, we noted one point of confusion caused by stating the

concept of proximate cause through a substantial-factor test is that a
juror might misunderstand proximate cause to mean the singular cause

nearest in time or location to the injury. 774 N.W.2d at 837;

Restatement (Third) § 29 cmt. b, at 494. Thus, a juror could conclude

the act of negligence must be in the same location as the harm, that

there might be only one legal cause of the injury, or that the cause must

be the last substantial factor in a chain. These factors tend to increase,

not decrease, barriers to liability.    See Matsuyama v. Birnbaum, 890
N.E.2d 819, 842–43 (Mass. 2008) (concluding a requirement that the

plaintiff prove negligence was a substantial contributing factor in a death

arguably imposed a higher burden than requiring the plaintiff to prove

negligence reduced the chances of survival). This would effectively raise

the plaintiff’s burden by creating a more demanding scope-of-liability

standard. At the same time, a situation may be conceivable in which

alleged negligent conduct is a substantial factor in bringing about harm,

but nonetheless the harm is not within the actor’s scope of liability. In

that case, a substantial-factor instruction would effectively decrease the

plaintiff’s burden to show the conduct was within the actor’s scope of
liability.
                                     12

         Here, we can easily conclude the erroneous substantial-factor

instruction created a more demanding instruction than the proper

Restatement (Third) scope-of-liability instruction.   The brachial plexus

injury was established as a matter of law to be within Onuigbo’s scope of

liability. Therefore, submission of any instruction on causation to the

jury beyond one pertaining only to factual causation increased Asher’s

burden by making it more difficult for her to obtain a favorable verdict.

Because the jury found in favor of Asher notwithstanding her increased

burden, the error was not prejudicial and does not constitute reversible
error.     See Hagenow v. Schmidt, 842 N.W.2d 661, 677 (Iowa 2014)

(concluding error was harmless where the defendant prevailed on the

sudden-emergency defense and the district court’s wording of the

sudden-emergency instruction made it more difficult to prove the

defense).

         IV. Substantial Evidence of Causation Regarding Use of the

Vacuum Extractor.

         A. Positions of the Parties.     Onuigbo claims Asher failed to

produce substantial evidence that his use of the vacuum extractor

caused the injury in this case. Onuigbo emphasizes that even Asher’s

experts testified the use of the vacuum extractor did not cause any injury

to the baby.     Onuigbo points to expert testimony indicating that the

vacuum extractor was simply used to pull the baby’s head outside the

vulva and that the instrument itself did not cause injuries.

         Asher responds that there was substantial evidence that Onuigbo’s

election to use the vacuum extractor increased the chance the baby

would develop shoulder dystocia. Further, Asher notes there is no legal
requirement that Onuigbo’s use of the vacuum extractor directly cause

the injury or be the sole cause of the injuries. If Onuigbo had recognized
                                    13

the shoulder dystocia caused by the vacuum extractor, Asher argues, he

could have performed maneuvers to free the shoulder from the pubic

bone.    Instead, Asher points out, Onuigbo applied lateral traction to

deliver the baby, causing the brachial plexus injury.

        B. Analysis.   We agree with Onuigbo the use of the vacuum

extractor itself did not directly cause the injury to the baby. However, a

reasonable jury could conclude that using the vacuum extractor led to

the shoulder dystocia, that Onuigbo failed to diagnose the shoulder

dystocia, and that when Onuigbo subsequently applied traction to deliver
the baby, the injury occurred.      It is not necessary that an act of

negligence be the last link in the causal chain leading to injury to

establish factual causation. Under the Restatement (Third), “Conduct is

a factual cause of harm when the harm would not have occurred absent

the conduct.”    Restatement (Third) § 26, at 346.      Comment c to this

section elaborates on the principle, noting that there can be multiple

causes of injury in a chain of events. Id. § 26 cmt. c, at 347–48. We

have long held an alleged negligent act or omission must be the direct

instrumentality of harm. See, e.g., State v. Tribble, 790 N.W.2d 121, 127

& n.2 (Iowa 2010) (noting that when multiple causes are present, each

sufficient to cause the injury, each is a factual cause of the harm).

Asher’s experts testified the use of a vacuum extractor significantly

increased the risk of shoulder dystocia, which in turn led to the brachial

plexus injury when lateral traction was applied. Based on the Asher’s

expert testimony in this case, a reasonable jury could find Onuigbo’s use

of the vacuum extractor set in motion a series of events leading to the

brachial plexus injury.   As a result, the district court did not err in
submitting the specification of negligence based upon Onuigbo’s use of

the vacuum extractor.
                                       14
     V. Substantial Evidence of Causation on Failure to Document
Progress of Labor.
         A. Positions of the Parties. Onuigbo contends the evidence was

insufficient to support a specification of negligence based upon his

failure to adequately document the progress of the labor.          Onuigbo

asserts the reason for maintaining adequate documentation is to ensure

other physicians who might assume responsibility for the delivery have

an adequate and accurate history to rely upon. In this case, however,

Onuigbo was the only physician attending Larysa during her labor.

Further, Onuigbo claims the failure to document the baby’s station did

not cause anything except a less-documented chart. Onuigbo argues no

reasonable jury could conclude the failure to write information on pieces

of paper caused the brachial plexus injury.

         Asher argues the evidence established Onuigbo’s failure to

document the progress of labor consistent with the standard of care.

Asher further claims that had the labor been properly documented, a

reasonable jury could conclude the injuries to the baby would not have

occurred.     If Onuigbo had maintained proper documentation, Asher

asserts, Onuigbo would have recognized the protracted nature of each

stage of labor.     Asher argues that in order to evaluate the risk of a

traumatic     vaginal   delivery,   Onuigbo   should   have   assessed   and
documented the fetus’s descent every hour during the second stage of

labor.

         B. Analysis. Expert testimony is ordinarily required on causation

in medical negligence cases.        See Doe v. Cent. Iowa Health Sys., 766
N.W.2d 787, 792 (Iowa 2009) (“The longstanding Iowa rule is that in a

tort action the necessity of expert testimony or the quality of necessary
expert testimony determines whether substantial evidence supports the

submission of the causal relationship between the act of the wrongdoer
                                     15

and the injury.”). There is, however, an exception to the general rule.

Expert medical testimony is not required on causation where an

untrained lay person would be qualified through ordinary knowledge and

experience to determine the issue.        Id. at 793; see also Stickleman v.

Synhorst, 243 Iowa 872, 878–79, 52 N.W.2d 504, 508 (1952) (finding it to

be within the realm of common layperson knowledge that one can suffer

serious blood loss due to a puncture wound to the neck). Regardless of

whether causation requires an expert, causation cannot be established

through guesswork or speculation. See Boswell v. Kearns Garden Chapel
Funeral Home, 227 Iowa 344, 346, 288 N.W. 402, 403 (1939). At the

same time, we recognize a probability or likelihood of a causal connection

is sufficient to generate a jury question.     Hansen v. Cent. Iowa Hosp.

Corp., 686 N.W.2d 476, 485 (Iowa 2004).

      In order to fully explore the causation issue, we will review the

expert testimony to understand the context in which the documentation

question arose.    We then consider whether Asher offered sufficient

evidence on factual causation to allow a jury to find Onuigbo liable on

the failure-to-document specification.       In the discussion, it will be

important to keep in mind the distinction between breach of duty and

causation.   See Tyler v. Dworkin, 747 A.2d 111, 122 (Del. Super. Ct.)

(distinguishing in medical records context between breach of duty and

causation), aff’d, 741 A.2d 1028 (Del. 1999).

      One of Asher’s experts, Dr. Paul Gatewood, testified that during

the first stage of labor (from the beginning of labor to complete dilation of

the cervix), the standard of care requires cervical dilation and the station

of the fetus in the birth canal be recorded at minimum every two hours.
This latter measurement aids the obstetrician in tracking the descent of

the fetus through the birth canal. During the second stage of labor (from
                                      16

complete dilation to birth), Gatewood testified, the station of the baby

must be documented hourly. In particular, Gatewood opined Onuigbo’s

failure to document the station of the fetus during the second stage of

labor    violated   the   standard   of   care.   According   to   Gatewood,

documentation allows “an obstetrician to come in hours later, take one

look at the curve, and know how the labor has gone.” Gatewood testified

that if an obstetrician has multiple patients in labor, it may be difficult to

recall the progress of each patient’s labor without documentation.

According to Gatewood,

        If he’s got two or three other people in labor, is he gonna
        necessarily remember what every exam was that he did on
        each patient that’s in labor at the same time? Probably not.
        So, it’s the documentation that allows the physician to
        refocus every time he comes in to evaluate the patient and
        make a determination if it’s a normal labor.

Gatewood further noted regular documentation of the fetus’s descent

through the birth canal in the second stage of labor “would increase

one’s level of awareness and alert the doctor that we may have a

problem.”

        Gatewood further testified Onuigbo breached this standard of care

because there was no documentation of the fetus’s station between 8:00

p.m. and the time the baby was born, 2:26 a.m. the next day. He further

noted the first stage of labor ended, at the latest, by 10:00 p.m.

According to Gatewood, this meant there was no documentation of the

fetus’s station during approximately the final six and one-half hours of

the labor, which included at least an approximately four-and-one-half-

hour-long second stage.
                                              17

         In addition, Gatewood testified ninety-five percent of women in

labor reach the end of the active phase of the first stage of labor2 within

five hours and, because the active phase of her labor began at 9:30 a.m.,

the active phase of Asher’s first stage lasted twelve and one-half hours,

which included two protractions, one of which occurred after Asher had

been administered Pitocin, a drug that increases the power of

contractions.3 Gatewood described the protraction of the first stage as

“significant.”   He further testified that because the length of the first

stage indicated a problem beyond the power of contractions pushing the
fetus through the birth canal, there was a further complication slowing

the labor.

         Gatewood then testified the average length of the second stage of

labor for a nullipara, a woman who has never given birth before, who has

received an epidural, like Asher, is ninety minutes and that ninety-five

percent of nulliparas who receive epidurals deliver within three and one-

half hours of complete dilation.              He then noted the second phase of

Asher’s labor lasted nearly four and one-half hours, which indicated a

third protraction.

         Gatewood testified a protracted labor of this type indicates an

increased risk of shoulder dystocia and that an obstetrician faced with

the circumstances of Asher’s labor should be tuned in to what is causing

the protraction and that it might be a problem with the baby fitting

         2Gatewood   testified that the first stage of labor is broken into a latent and active
stage.
       3Gatewood testified obstetricians must constantly monitor power, which comes

from contractions; the passenger, which is the fetus; and the pelvis, which is the bony
structure the fetus must pass through. Asher was administered Pitocin at 4:00 p.m.,
which according to Gatewood meant she had experienced a protraction disorder prior to
that time. Gatewood further testified the fact the first stage did not end until 10:00
p.m. indicated a second protraction during the first stage.
                                     18

through the pelvis. He further testified that based on all of the facts and

circumstances of Asher’s labor, her baby should have been delivered via

a caesarian section. He testified that while it is possible a permanent

brachial plexus injury could have occured with a caesarian section

delivery, the risk was significantly reduced.

      Asher’s other expert, Dr. James Rice, offered substantially similar

testimony as to the standard of care in documenting the labor.        Like

Gatewood, Rice opined Asher violated that standard of care and, based

on the facts and circumstances surrounding Asher’s labor, her baby
should have been delivered via a caesarian section.

      Onuigbo also offered expert testimony and testified himself as to

the standard of care and the facts and circumstances surrounding

Asher’s labor. In sum, Onuigbo and his experts downplayed the length

of the labor and rate of progress of fetal descent and emphasized fetal

monitoring and the need to avoid a caesarian section whenever possible.

However, the jury was free to assign no weight to the testimony of

Onuigbo and his experts and disregard it entirely. See, e.g., Top of Iowa

Coop. v. Sime Farms, Inc., 608 N.W.2d 454, 468 (Iowa 2000) (noting a

jury may “discount some testimony and give more credit to other

testimony”); Mensink v. Am. Grain, 564 N.W.2d 376, 382 (Iowa 1997)

(noting a jury is free to disregard expert testimony).

      We conclude, based on the record, that Asher presented sufficient

evidence to reach a jury on the question of whether the failure to

document caused the injury.       A reasonable jury could infer from the

evidence that Onuigbo was inattentive to the progress of the baby and

that his failure to regularly document the progress was a cause of the
baby’s injuries. As Gatewood testified, the lack of information available

to Onuigbo increased the risk of harm to the baby, thereby providing
                                     19

expert support for causation. In evaluating expert support for causation,

we do not require magic words, and the evidence on causation need not

be conclusive but must only show reasonable probability. See Soreide v.

Vilas & Co., 247 Iowa 1139, 1143, 78 N.W.2d 41, 43–44 (1956); Ramberg

v. Morgan, 209 Iowa 474, 482, 218 N.W.2d 492, 497 (1928).                A

reasonable jury could infer from the trial testimony that had Onuigbo

ensured that the baby’s station was duly recorded hourly in the chart, he

would have realized that he faced either an arrest of labor or a severe

protraction disorder requiring an exploration of options other than
vaginal delivery.

        VI. Conclusion.

        For the above reasons, we conclude that although the district court

gave an erroneous causation instruction based on the abandoned

substantial-factor test instead of on the scope of Onuigbo’s liability, the

error was not prejudicial and does not require reversal of the jury’s

verdict.    We find substantial evidence supporting a finding that

Onuigbo’s use of the vacuum extractor was a factual cause of Asher’s

injuries and conclude Asher engendered a jury question on the causal

relationship between Onuigbo’s failure to adequately document the

progress of the labor and the claimed injury and damages. As a result,

the judgment is affirmed.

        AFFIRMED.

        All justices concur except Mansfield and Zager, JJ., who take no

part.