OPINION

On July 17, 1975, appellee, Cheryl Rossetti, a fifth-grade teacher, requested a maternity leave from the Board of School Directors of Fox Chapel Area School District (the Board). The Board granted the requested maternity leave; and, upon a second request, it granted an additional four-week extension.1 Appellee was to resume her teaching duties on January 13,1976; but by letter of January 5,1976, *128appellee requested a leave of absence for the remainder of the 1975-76 school year. Appellee stated in this letter to the Superintendent of the Fox Chapel Area School District that her “duties as a new mother, which include breast-feeding” necessitated the requested leave of absence. The Superintendent responded by stating that the Collective Bargaining Agreement contained no provisions for child-rearing leave. On the day prior to the scheduled commencement of appellee’s teaching duties, she and a field representative of the Pennsylvania State Education Association attempted to procure from the Board an unpaid leave of absence purportedly in order to breast-feed the child as a preventive measure against allergies.2 This request was denied by the Board, and appellee refused to return to work and resume her teaching responsibilities even though so ordered.

On February 19,1976, the Board filed charges of dismissal against appellee. Hearings were then held on these matters before the Board on March 4, 1976, and again on May 18, 1976. At the conclusion of these hearings, the Board voted unanimously to dismiss appellee.

Appellee subsequently filed an appeal with the Secretary of Education (Secretary) who by order dated December 27, 1976, Teacher Tenure Appeal No. 300, directed the Board to reinstate appellee without loss of pay, seniority or accrued benefits. The Board sought review of the Secretary’s order in the Commonwealth Court and that court affirmed the order of the Secretary. Board of School Directors of Fox Chapel v. Rossetti, 36 Pa.Cmwlth. 105, 387 A.2d 957 (1978). The Commonwealth Court held:

[s]ince the development of the law in this area has been based upon the unique position of the female confronted *129with the prospect of childbirth, it follows that the request for additional leave for breastfeeding purposes under the circumstances of this case is merely a logical and natural extension of that concept. Consequently, the refusal of the Board to grant respondent’s request for an unpaid leave of absence . . . amounted to an unlawful discriminatory practice .... Id., 36 Pa.Cmwlth. at 112-113, 387 A.2d at 960.

We granted the Board’s petition for allowance of appeal and now reverse.

Appellee first contends that her request for a leave of absence falls within the purview of the maternity-leave provision of the Collective Bargaining Agreement3 and not within the discretionary-leave provision as the Board asserts.4 The entire record, however, shows that there was substantial evidence to support the Board’s position. First, the maternity-leave provision provides that each extension shall not exceed thirty days; yet, appellee, in fact, sought a leave of absence far in excess of that period. On January 5, 1976, she sought a leave for the remainder of the 1975-76 school year. Secondly, the maternity-leave provision provides that requests for extensions must be accompanied by a physician’s certificate establishing the need for the exten*130sion. Yet appellee stated in her letter to the Board (wherein she requested a leave of absence) that her obstetrician would not certify her need for another extension since, in his judgment, she had recovered from pregnancy. Thirdly, the Board hearings established that appellee was both physically and mentally fit to resume her teaching responsibilities; and, in that situation, the maternity-leave provision expressly provides that “[t]he maternity leave will end upon the [Professional Employee’s] recovering the ability to follow her occupation.” Finally, the maternity-leave provision makes no mention of extensions for health needs other than for the woman’s own recovery; yet, appellee’s request was based upon maternal duties generated by her child’s health needs.

Based on the above, it was reasonable for the Board to conclude that its only contractual obligation was to consider granting appellee an unpaid, discretionary leave of absence5 and not a maternity-leave extension. Furthermore, where a reasonable person acting reasonably might have reached the same decision as the Board, then there is substantial evidence for the Board’s determination which should not then be disturbed on appeal. Penn-Delco School Dist. v. Urso, 33 Pa.Cmwlth. 501, 511, 382 A.2d 162, 167 (1978).

Appellee’s second contention is that she was, nevertheless, sexually discriminated against by the Board’s failure to grant her the discretionary leave of absence to discharge her maternal duties. Appellee cites as support for her proposition this Court’s holding that pregnancy-based discrimination constitutes sex discrimination in violation of *131Section 5(a) of the Pennsylvania Human Relations Act.6 Cerra v. East Stroudsburg Area School Dist., 450 Pa. 207, 299 A.2d 277 (1973). The evil which the Pennsylvania Human Relations Act seeks to overcome is the dissimilar treatment, on the basis of sex, of persons similarly situated. But appellee has in no way suggested that male teachers have been or would be granted discretionary leaves of absence while females were denied them. To the contrary, appellee has been treated no differently then any male teacher would be who had to remain at home to care for a physically or emotionally disabled newborn infant.7

Hence, appellee’s failure to return to work was without any legal justification and her dismissal by the Board was for proper cause.8 Any other result would create the anomalous situation of a school board’s having lawfully exercised its bargained-for discretion, determining that its employee must return to work, and yet be without any power to terminate the employment relationship in the face of an employee’s refusal to comply.

*132For the foregoing reasons, the order of the Commonwealth Court in affirming the decision of the Secretary of Education is reversed; and the Board’s determination as to appellee’s dismissal is reinstated.

dissenting.

The majority holds that the School Board’s refusal to grant appellee Cheryl Rossetti an unpaid leave of absence for purposes of breastfeeding her allergy-prone infant does not violate the Pennsylvania Human Relations Act, Act of October 27,1955, P.L. 744, as amended, 43 P.S. §§ 951 et seq. (Supp.1978-79). Since I conclude that the action of the School Board constitutes an unlawful discriminatory practice within the meaning of section 5(a) of the Act, I must dissent.

While the School Board may provide for discretionary unpaid leave, 16 Pa.Code § 41.104(a),* it may not exercise its discretion in a discriminatory manner. Section 5(a) of the Pennsylvania Human Relations Act provides that it is an unlawful discriminatory practice for:

“any employer because of . sex ... to discharge from employment such individual, or to otherwise discriminate against such individual with respect to compensation, hire, tenure, terms, conditions or privileges of employment, if the individual is the best able and most competent to perform the services required.”

*133The School Board’s denial of discretionary leave to appellee for purposes of medically-recommended breastfeeding clearly violates this provision.

The majority contends that “appellee has been treated no differently than any male teacher would be who had to remain at home to care for a physically or emotionally disabled newborn infant.” This position ignores the obvious reality that only women can perform the breastfeeding function. Thus when the School Board arbitrarily denies discretionary leave sought for reasons unique to women, the School Board is discriminating on the basis of sex. The Legislature expressly proscribed such discriminatory practices in the Pennsylvania Human Relations Act. See Cerra v. East Stroudsburg Area School District, 450 Pa. 207, 299 A.2d 277 (1973) (regulation requiring resignation of teachers at fifth month of pregnancy held to violate § 5(a)); Anderson v. Upper Bucks County Area Vocational Technical School, 30 Pa.Cmwlth. 103, 373 A.2d 126 (1977) (collective bargaining provision prohibiting application of accumulated sick leave to maternity leave constituted sex discrimination).

Accordingly, I would affirm the Commonwealth Court’s order which affirmed the order of reinstatement by the Secretary of Education.