opinion: Mr. Justice Black
  delivered the opinion of the Court.
  Appellee Milan Yuitch, a licensed physician, was indicted in the United States District Court for the District of Columbia for producing and attempting to produce abortions in violation of D. C. Code Ann. § 22-201 (1967). Before trial, the district judge granted Vuitch’s motion to dismiss the indictments on the ground that the District of Columbia abortion law was unconstitutionally vague. 305 F. Supp. 1032 (DC 1969). The United States appealed to this Court under the Criminal Appeals Act, 18 U. S. C. § 3731. We postponed decision on jurisdiction to the hearing on the merits, 397 U. S. 1061, and requested the parties to brief and argue specified questions on that issue. 399 U. S. 923. We hold that we have jurisdiction and that the statute is not unconstitutionally vague. We reverse.
  I
  The first question is whether we have jurisdiction under the Criminal Appeals Act to entertain this direct appeal from the United States District Court for the District of Columbia. That Act gives us jurisdiction over direct appeals from district court judgments “in all criminal cases . . . dismissing any indictment . . . where such decision ... is based upon the invalidity ... of the statute upon which the indictment ... is founded.” 18 U. S. C. § 3731. The decision appealed from is a dismissal of indictments on the ground that the District of Columbia abortion law, on which the indictments were based, is unconstitutionally vague. This abortion statute, D. C. Code Ann. § 22-201, is an Act of Congress applicable only in the District of Columbia and we suggested that the parties argue whether a decision holding unconstitutional such a statute is appealable directly to this Court under the Criminal Appeals Act. The literal wording of the Act plainly includes this statute, even though it applies only to the District. A piece of legislation so limited is nevertheless a “statute” in the sense that it was duly enacted into law by both Houses of Congress and was signed by the President. And the Criminal Appeals Act contains no language that purports to limit or qualify the term “statute.” On the contrary, the Act authorizes Government appeals from district courts to the Supreme Court in “all criminal cases” where a district court judgment dismissing an indictment is based upon the invalidity of the statute on which the indictment is founded.
  An examination of the legislative history of the Criminal Appeals Act and its amendments suggests no reason why we should depart from the Act’s literal meaning and exclude District of Columbia (hereafter sometimes D. C.) statutes from its coverage. The committee reports and floor debates contain no discussion indicating that the term “statute” does not include statutes applicable only to the District of Columbia. We therefore conclude that we have jurisdiction over this appeal under the Criminal Appeals Act.
  Our Brother Harlan has argued in dissent that we do not have jurisdiction over this direct appeal. He suggests that such a result is supported by the decision in United States v. Burroughs, 289 U. S. 159 (1933), the policy underlying the Criminal Appeals Act, and the canon of construction that statutes governing direct appeals to this Court should be strictly construed.
  It is difficult to see how the Burroughs decision lends much force to his argument, since that case held only that the term “district court” in the Criminal Appeals Act did not include the then-existing Supreme Court of the District of Columbia. Id., at 163-164. The dissent goes on to suggest the Act should be construed in light of the congressional purpose of avoiding “inconsistent enforcement of criminal laws.” Post, at 92. This purpose would not be served by our refusing to decide this case now after it has been orally argued. In the last several years, abortion laws have been repeatedly attacked as unconstitutionally vague in both state and federal courts with widely varying results. A number of these cases are now pending on our docket. A refusal to accept jurisdiction here would only compound confusion for doctors, their patients, and law enforcement officials. As this case makes abundantly clear, a ruling on the validity of a statute applicable only to the District can contribute to great disparities and confusion in the enforcement of criminal laws. Finally, my Brother Harlan’s dissent also appears to rely on the fact that this Court has never accepted jurisdiction over a direct appeal under the Criminal Appeals Act involving the validity of a District of Columbia statute. Post, at 93. Since this Court has never either accepted or rejected jurisdiction of such an appeal, it is difficult to see how the complete absence of precedent in this Court lends any weight whatever to his argument. Neither previous cases nor the purpose behind the Criminal Appeals Act provides any satisfactory reason why the term “statute” should not include those statutes applicable only in the District of Columbia.
  One other procedural problem remains. We asked the parties to brief the question whether the Government could have appealed this case to the Court of Appeals for the District of Columbia Circuit under D. C. Code Ann. § 23-105 (Supp. 1970), and, if so, whether we should refuse to entertain the appeal here as a matter of sound judicial administration. That D. C. Code provision states:
  “In all criminal prosecutions the United States . . . shall have the same right of appeal that is given to the defendant . ,
  The relationship between the Criminal Appeals Act and this Code section was considered in Carroll v. United States, 354 U. S. 394, 411 (1957), where the Court concluded:
  “[C]riminal appeals by the Government in the District of Columbia are not limited to the categories set forth in 18 U. S. C. § 3731 [the Criminal Appeals Act], although as to cases of the type covered by that special jurisdictional statute, its explicit directions will prevail over the general terms of [D. C. Code Ann. § 23-105 (Supp. 1970) ]
  Since we have concluded above that this appeal is covered by the Criminal Appeals Act, it would seem to follow from Carroll that the Act's provisions control and no appeal could have been taken to the Court of Appeals. Although Carroll seems to be dispositive, it has been suggested that it may now be limited by United States v. Sweet, 399 U. S. 517 (1970), which contains some language suggesting that the Government may be empowered to take an appeal to the Court of Appeals under § 23-105 even when a direct appeal would be proper here under the Criminal Appeals Act. Id., at 518. We do not elaborate upon that suggestion. We only hold that once an appeal is properly here under the Criminal Appeals Act, we should not refuse to consider it because it might have been taken to another court.
  II
  We turn now to the merits. Appellee Milan Yuitch was indicted for producing and attempting to produce abortions in violation of D. C. Code Ann. § 22-201. That Act provides in part:
  “Whoever, by means of any instrument, medicine, drug or other means whatever, procures or produces, or attempts to procure or produce an abortion or miscarriage on any woman, unless the same were done as necessary for the preservation of the mother’s life or health and under the direction of a competent licensed practitioner of medicine, shall be imprisoned in the penitentiary not less than one year or not more than ten years . . .
  Without waiting for trial, the District Judge dismissed the indictments on the ground that the abortion statute was unconstitutionally vague. In his view, set out substantially in full below, the statute was vague for two principal reasons:
  1. The fact that once an abortion was proved a physician “is presumed guilty and remains so unless a jury can be persuaded that his acts were necessary for the preservation of the woman’s life or health.”
  2. The presence of the “ambivalent and uncertain word ‘health.’ ”
  In concluding that the statute places the burden of persuasion on the defendant once the fact of an abortion has been proved, the court relied on Williams v. United States, 78 U. S. App. D. C. 147, 138 F. 2d 81 (1943). There the Court of Appeals for the District of Columbia Circuit held that the prosecution was not required to prove as part of its case in chief that the operation was not necessary to preserve life or health. Id., at 147, 149, 138 F. 2d, at 81, 83. The court indicated that once the prosecution established that an abortion had been performed the defendant was required “to come forward with evidence which with or without other evidence is sufficient to create a reasonable doubt of guilt.” Id., at 150, 138 F. 2d, at 84. The District Court here appears to have read Williams as holding that once an abortion is proved, the burden of persuading the jury that it was legal (i. e., necessary to the preservation of the mother’s life or health) is cast upon the physician. Whether or not this is a correct reading of Williams, we believe it is an erroneous interpretation of the statute. Certainly a statute that outlawed only a limited category of abortions but “presumed” guilt whenever the mere fact of abortion was established, would at the very least present serious constitutional problems under this Court's previous decisions interpreting the Fifth Amendment. Tot v. United States, 319 U. S. 463 (1943); Leary v. United States, 395 U. S. 6, 36 (1969). But of course statutes should be construed whenever possible so as to uphold their constitutionality.
  The statute does not outlaw all abortions, but only those which are not performed under the direction of a competent, licensed physician, and those not necessary to preserve the mother’s life or health. It is a general guide to the interpretation of criminal statutes that when an exception is incorporated in the enacting clause of a statute, the burden is on the prosecution to plead and prove that the defendant is not within the exception. When Congress passed the District of Columbia abortion law in 1901 and amended it in 1953, it expressly authorized physicians to perform such abortions as are necessary to preserve the mother’s “life or health.” Because abortions were authorized only in more restrictive circumstances under previous D. C. law, the change must represent a judgment by Congress that it is desirable that women be able to obtain abortions needed for the preservation of their lives or health. It would be highly anomalous for a legislature to authorize abortions necessary for life or health and then to demand that a doctor, upon pain of one to ten years’ imprisonment, bear the burden of' proving that an abortion he performed fell within that category. Placing such a burden of proof on a doctor would be peculiarly inconsistent with society’s notions of the responsibilities of the medical profession. Generally, doctors are encouraged by society’s expectations, by the strictures of malpractice law and by their own professional standards to give their patients such treatment as is necessary to preserve their health. We are unable to believe that Congress intended that a physician be required to prove his innocence. We therefore hold that under D. C. Code Ann. § 22-201, the burden is on the prosecution to plead and prove that an abortion was not “necessary for the preservation of the mother’s life or health.”
  There remains the contention that the word “health” is so imprecise and has so uncertain a meaning that it fails to inform a defendant of the charge against him and therefore the statute offends the Due Process Clause of the Constitution. See, e. g., Lanzetta v. New Jersey, 306 U. S. 451 (1939). We hold that it does not. The trial court apparently felt that the term was vague because there “is no indication whether it includes varying degrees of mental as well as physical health.” 305 F. Supp., at 1034. It is true that the legislative history of the statute gives no guidance as to whether “health” refers to both a patient’s mental and physical state. The term “health” was introduced into the law in 1901 when the statute was enacted in substantially its present form. The House Report on the bill contains no discussion of the term “health” and there was no Senate report. Nor have we found any District of Columbia cases prior to this District Court decision that shed any light on the question. Since that decision, however, the issue has been considered in Doe v. General Hospital of the District of Columbia, 313 F. Supp. 1170 (DC 1970). There District Judge Waddy construed the statute to permit abortions “for mental health reasons whether or not the patient had a previous history of mental defects.” Id., at 1174-1175. The same construction was followed by the United States Court of Appeals for the District of Columbia Circuit in further proceedings in the same case. 140 U. S. App. D. C. 149 and 153, 434 F. 2d 423 and 427 (1970). We see no reason why this interpretation of the statute should not be followed. Certainly this construction accords with the general usage and modern understanding of the word “health,” which includes psychological as well as physical well-being. Indeed Webster’s Dictionary, in accord with that common usage, properly defines health as the “[s]tate of being . . . sound in body [or] mind.” Viewed in this light, the term “health” presents no problem of vagueness. Indeed, whether a particular operation is necessary for a patient’s physical or mental health is a judgment that physicians are obviously called upon to make routinely whenever surgery is considered.
  We therefore hold that properly construed the District of Columbia abortion law is not unconstitutionally vague, and that the trial court erred in dismissing the indictments on that ground. Appellee has suggested that there are other reasons why the dismissal of the indictments should be affirmed. Essentially, these arguments are based on this Court’s decision in Griswold v. Connecticut, 381 U. S. 479 (1965). Although there was some reference to these arguments in the opinion of the court below, we read it as holding simply that the statute was void for vagueness because it failed in that court’s language to “give that certainty which due process of law considers essential in a criminal statute.” 305 F. Supp., at 1034. Since that question of vagueness was the only issue passed upon by the District Court it is the only issue we reach here. United States v. Borden Co., 308 U. S. 188 (1939); United States v. Petrillo, 332 U. S. 1 (1947); United States v. Blue, 384 U. S. 251, 256 (1966).
  The judgment is reversed and the case remanded for further proceedings not inconsistent with this opinion.
  Reversed.
  The Chief Justice, Mr. Justice Douglas, Mr. Justice Stewart, and Mr. Justice White join in Part I of this opinion. The Chief Justice, Mr. Justice HarlaN, Mr. Justice White, and Mr. Justice BlackmuN join in Part II of this opinion.
  The Act states in pertinent part:
  “An appeal may be taken by and on behalf of the United States from the district courts direct to the Supreme Court of the United States in all criminal cases in the following instances:
  “From a decision or judgment setting aside, or dismissing any indictment or information, or any count thereof, where such decision or judgment is based upon the invalidity or construction of the statute upon which the indictment or information is founded.” 18 U. S. C. § 3731.
  See H. R. Conf. Rep. No. 8113, 59th Cong., 2d Sess.; H. R. Rep. No. 2119, 59th Cong., 1st Sess.; H. R. Rep. No. 45 and S. Rep. No. 868, 77th Cong., 1st Sess.; H. R. Conf. Rep. No. 2052, 77th Cong., 2d Sess.
  The District Judge stated:
  “It is suggested that these words ['as necessary for the preservation of the mother’s life or health’] are not precise; that, as interpreted, they improperly limit the physician in carrying out his professional responsibilities; and that they interfere with a woman’s right to avoid childbirth for any reason. The word ‘health’ is not defined and in fact remains so vague in its interpretation and the practice under the act that there is no indication whether it includes varying degrees of mental as well as physical health. While the law generally has been careful not to interfere with medical judgment of competent physicians in treatment of individual patients, the physician in this instance is placed in a particularly unconscionable position under the conflicting and inadequate interpretations of the D. C. abortion statute now prevailing. The Court of Appeals established by such early cases as Peckham v. United States, 96 U. S. App. D. C. 312, 226 F. 2d 34 (1955), cert. denied 350 U. S. 912, 76 S. Ct. 195, 100 L. Ed. 800, and Williams v. United States, 78 U. S. App. D. C. 147, 138 F. 2d 81, 153 A. L. R. 1213 (1943), that upon the Government establishing that a physician committed an abortion, the burden shifted to the physician to justify his acts. In other words, he is presumed guilty and remains so unless a jury can be persuaded that his acts were necessary for the preservation of the woman’s life or health. These holdings, which may well offend the Fifth Amendment of the Constitution, as interpreted in recent decisions such as Leary v. United States, 395 U. S. 6, 89 S. Ct. 1532, 23 L. Ed. 2d 57 (1969), and United States v. Gainey, 380 U. S. 63, 85 S. Ct. 754, 13 L. Ed. 2d 658 (1965), also emphasize the lack of necessary precision in this criminal statute. The jury’s acceptance or nonacceptance of an individual doctor’s interpretation of the ambivalent and uncertain word ‘health’ should not determine whether he stands convicted of a felony, facing ten years’ imprisonment. His professional judgment made in good faith should not be challenged. There is no clear standard to guide either the doctor, the jury or the Court. No body of medical knowledge delineates what degree of mental or physical health or combination of the two is required to make an abortion conducted by a competent physician legal or illegal under the Code. . . .” 305 F. Supp. 1032, 1034.
  The trial court also cited Peckham v. United States, 96 U. S. App. D. C. 312, 226 F. 2d 34 (1955), as dealing with the D. C. abortion law. However, the opinion in that case does not discuss the burden of proof under the statute.
  Before 1901 the existing statute allowed abortion only “for the purpose of preserving the life of any woman pregnant.” W. Abert & B. Lovejoy, The Compiled Statutes in Force in the District of Columbia, c. XVI, § 15, p. 159 (1894).
  H. R. Rep. No. 1017, 56th Cong., 1st Sess.
  Our Brother Douglas appears to fear that juries might convict doctors in any abortion case simply because some jurors believe all abortions are evil. Of course such a danger exists in all criminal cases, not merely those involving abortions. But there are well-established methods defendants may use to protect themselves against such jury prejudice: continuances, changes of venue, challenges to prospective jurors on voir dire, and motions to set aside verdicts which may have been produced by prejudice. And of course a court should always set aside a jury verdict of guilt when there is not evidence from which a jury could find a defendant guilty beyond a reasonable doubt.