The Act Commentary on Sections Part 2 - Criminal offences Section 57:  Infanticide (England and Wales)
351.Section 57 amends section 1 of the Infanticide Act 1938 so that it is clear that the offence and defence of infanticide are available only in respect of a woman who would otherwise be found guilty of murder or manslaughter. Whilst it had generally been assumed in the past that infanticide could apply only in circumstances that would otherwise amount to the offence of murder, the Court of Appeal ruled in R v Gore [2007] EWCA Crim 2789 that section 1 may apply whenever the requirements of infanticide are made out regardless of what offence would otherwise have been committed.
352.Section 57 limits infanticide to cases that would otherwise be murder or manslaughter through two changes. The first is to replace the words “notwithstanding that” with the word “if”. This resolves an uncertainty that has existed in the past about the meaning of the term “notwithstanding that” which at different times has been interpreted as meaning “even if” and “provided that”.
353.The second is to explicitly state that infanticide can apply (provided all the other criteria for infanticide apply) where the offence would otherwise be murder or manslaughter.
354.The combined effect of the two changes is that infanticide can apply “if the circumstances were such that but for the Infanticide Act 1938 the offence would have amounted to murder or manslaughter”.