A Superior Court judge ruled that the evidence was not sufficient to raise a question for the jury on the plaintiff’s claim that each defendant physician had failed in his duty to disclose in a reasonable manner certain medical information that would have been material to an intelligent decision by the pregnant plaintiff whether to have labor induced or to wait for spontaneous labor. The Appeals Court *876concluded, however, that the evidence presented a jury question whether each defendant should have realized that, if he had disclosed the risk of infection to the child which the decision to await natural labor presented, that disclosure would have been material to the plaintiff mother’s decision in choosing between the alternative courses of treatment. Feeley v. Baer, 41 Mass. App. Ct. 239, 243-244 (1996). We granted the defendant doctors’ applications for further appellate review.
We agree with the trial judge. The evidence would not permit a finding that the risk to the child of serious infection was more than negligible. “The materiality of information about a potential injury is a function not only of the severity of the injury, but also of the likelihood that it will occur. Regardless of the severity of a potential injury, if the probability that the injury will occur is so small as to be practically nonexistent, then the possibility of that injury occurring cannot be considered a material factor in a rational assessment of whether to engage in the activity that exposes one to the potential injury.” Precourt v. Frederick, 395 Mass. 689, 694-695 (1985). See Harnish v. Children’s Hosp. Medical Ctr., 387 Mass. 152, 156 (1982).
The Appeals Court presented the facts underlying the claim as follows:
“In 1987, Donna Feeley (Feeley), Eric’s mother, became pregnant for the fourth time and experienced a normal course of pregnancy without any prenatal problems. On the morning of Monday, October 12, 1987, two days after her due date, Feeley’s water broke, and she was admitted to Beth Israel Hospital at noon. She was not in labor when she arrived at the hospital. Her treating physicians, the defendants Dr. Richard McNeer and Dr. Stephen Baer, without discussing the matter with Feeley, chose a course of treatment known as ‘expectant management.’ This approach is based upon the theory that once the membranes have ruptured, the pregnancy should proceed naturally to spontaneous labor without surgical intervention or medication to induce labor, provided that there is no indication of other reasons to intervene. Feeley went into labor on Wednesday evening and gave birth shortly thereafter.”
Feeley v. Baer, supra at 240. Eric died five days later of *877streptococcus pneumonia, which Feeley’s expert described as “a rare pathogen, and not one that’s routinely looked for,” but one that could be picked up in the birth canal.
All the experts acknowledged that once a woman’s membranes have ruptured, there is a risk of infection and that one must be alert for evidence of infection. There was evidence that the risk increases with time following the rupture. Such an infection can be simple or serious. The plaintiffs expert testified that Eric contracted the infection in his mother’s uterus and would not have done so if he had been delivered on Tuesday, the day after Feeley was admitted to the hospital.
The plaintiffs theory, which was accepted by the Appeals Court (.Feeley v. Baer, supra at 243), is that, because there was more than a negligible risk of infection, the doctors had to explain that risk and obtain Feeley’s informed consent to the course of treatment that they followed.3 We agree with the plaintiff that she did not have to prove that the risk to Eric of contracting streptococcus pneumonia itself was more than negligible. See McMahon v. Finlayson, 36 Mass. App. Ct. 371, 374-375 (1994) (obligation to disclose that there were risks to various organs in operative field which collectively would be material to patient’s decision). The risk that must exist in order to invoke informed consent principles in this case is a more than negligible risk of one or more infections that will have serious consequences.
The deficiency in the plaintiffs proof is that there was no evidence that pursuing the “expectant management” procedure created more than a negligible risk of serious infection from streptococcus pneumonia or any other possible serious infection. The allowance of the defendants’ motions for *878directed verdicts was correct. We agree with the Appeals Court on the other issues that it considered.4
Judgment affirmed.
There is no doubt that, in the circumstances, Feeley could exercise judgment and give informed consent on behalf of her unborn child.
The fact that one alternative involved in this case was “letting nature take its course,” that is, no invasive treatment, does not affect the informed consent analysis. See Harnish v. Children’s Hosp. Medical Ctr., 387 Mass. 152, 156 (1982) (“Appropriate information may include . . . the likely result of no treatment . . .”). See also Wecker v. Amend, 22 Kan. App. 2d 498, 502 (1996) (“in situations where no treatment at all is a reasonable medically acceptable option, common sense dictates that such information constitutes a fact” necessary to form the basis of an intelligent consent by the patient to the proposed treatment).
The doctors did not raise the issue to which the concurring opinion is directed either in their applications for further appellate review or in their supplemental briefs to this court.
Most authorities “prefer to treat informed consent liability solely as an aspect of malpractice or negligence.” 1 F. Harper, F. James, & O. Gray, Torts § 3.10, at 3:45-3:46 (3d ed. 1996). One reason is “that the problem of informed consent is essentially one of professional responsibility, not intentional wrongdoing, and can be handled more coherently within the framework of negligence law than as an aspect of battery.” Id. at 3:46-3:47.