Short answer. Yes. Article 166 of the Family Code expressly recognizes that legitimacy may be impugned where it is proved that for biological or other scientific reasons, the child could not have been that of the husband. DNA testing is the most common form of such evidence today, though the statute is not limited to any one scientific method.
What the law says
it is proved that for biological or other scientific reasons, the child could not have been that of the husband
Family Code, Article 166 — Grounds to Impugn Legitimacy. Read the full provision →
The statutory basis for scientific evidence
Article 166(2) of the Family Code provides that legitimacy may be impugned where "it is proved that for biological or other scientific reasons, the child could not have been that of the husband." This ground was drafted broadly — "biological or other scientific reasons" — to accommodate advances in science rather than tying the rule to techniques available in 1987. The standard is not proof of probability but proof that the child could not have been the husband's. That is a high bar: science must affirmatively exclude the husband as the biological father, not merely lower the probability.
The artificial insemination exception
There is one important carve-out. Article 166 refers to the instance provided in the second paragraph of Article 164: a child conceived by artificial insemination using the sperm of a donor, where both spouses authorized the procedure in writing, is legitimate even though the husband is not the biological father. Scientific evidence in that scenario would show the husband contributed no genetic material — yet the child remains legitimate because the written authorization was valid. Biology and law do not always point the same way.
Practical application: DNA evidence
In practice, the most commonly invoked form of scientific evidence today is DNA testing. A result that excludes the husband as the biological father with the statistical certainty that modern testing provides can establish, in the language of the statute, that "the child could not have been that of the husband." The question of whether and how such testing may be ordered, who may be compelled to provide samples, and how results are weighed is governed by the rules of evidence and court procedure rather than Article 166 itself.
The child's presumption and who may impugn
The starting point remains Article 164: children conceived or born during marriage are presumed legitimate. The grounds in Article 166 are exclusive — legitimacy may be challenged only on those grounds. The right to impugn belongs to specific persons identified in the Family Code, and must be exercised within the applicable period. A successful action on scientific grounds changes the child's civil status with consequences for succession, support, and parental authority — which is why the law builds in a presumption and requires proof before that status can be disturbed.
Cases citing this provision
These Supreme Court decisions cite the provision above. We list them so you can read them yourself; the summaries of what each decided are not ours to give.
- Bernie Santiago vs. Rommel C. Jornacion and The City Civil Registrar of Marikina City, G.R. No. 230049, October 6, 2021 — read the decision on LawPhil →
- Lowella Yap vs. Almeda Yap, Hearty Yap-Dybongco and Diosdado Yap, Jr, G.R. No. 222259, October 17, 2022 — read the decision on LawPhil →
- Richelle Busque Ordoña vs. The Local Civil Registrar of Pasig City and Allan D, G.R. No. 215370, November 9, 2021 — read the decision on LawPhil →
- Eugenio San Juan Geronimo vs Karen Santos, G.R. No. 197099, September 28, 2015 — read the decision on LawPhil →