Points of impact;

1. Social.
2. Economic.
3. Population decline.
4. Spiritual decline/ignorance.
5. Gender inequality in worshiping at Gurudwaras.

The basic underlying factor in female infanticide/inequality is the individual male EGO, spiritual ignorance as well as socio-economic factors.
If the spiritual ignorance is removed by respecting the female gender as Sikh Gurus tried to teach the humanity about it. Guru Nanak in Asa Di Var elucidates;

ਭੰਡਿ ਜੰਮੀਐ ਭੰਡਿ ਨਿੰਮੀਐ ਭੰਡਿ ਮੰਗਣੁ ਵੀਆਹੁ ॥ਭੰਡਹੁ ਹੋਵੈ ਦੋਸਤੀ ਭੰਡਹੁ ਚਲੈ ਰਾਹੁ ॥ਭੰਡੁ ਮੁਆ ਭੰਡੁ ਭਾਲੀਐ ਭੰਡਿ ਹੋਵੈ ਬੰਧਾਨੁ ॥ਸੋ ਕਿਉ ਮੰਦਾ ਆਖੀਐ ਜਿਤੁ ਜੰਮਹਿ ਰਾਜਾਨ ॥ਭੰਡਹੁ ਹੀ ਭੰਡੁ ਊਪਜੈ ਭੰਡੈ ਬਾਝੁ ਨ ਕੋਇ ॥ਨਾਨਕ ਭੰਡੈ ਬਾਹਰਾ ਏਕੋ ਸਚਾ ਸੋਇ ॥

Bẖand jammī­ai bẖand nimmī­ai bẖand mangaṇ vī­āhu.Bẖandahu hovai ḏosṯī bẖandahu cẖalai rāhu.Bẖand mu­ā bẖand bẖālī­ai bẖand hovai banḏẖān.So ki­o manḏā ākẖī­ai jiṯ jameh rājān.Bẖandahu hī bẖand ūpjai bẖandai bājẖ na ko­ė.Nānak bẖandai bāhrā ėko sacẖā so­ė.

From woman, man is born; within woman, man is conceived; to woman he is engaged and married. Woman becomes his friend; through woman, the future generations come. When his woman dies, he seeks another woman; to woman he is bound. So why call her bad? From her, kings are born. From woman, woman is born; without woman, there would be no one at all. O, Nanak, only the True Akal Purkh is without a woman.-----Guru Nanak, Raag Asa, AGGS, Page, 473

It is the ego, which by its veil separates the self from Truth/Universal Self. Ego/Houmai is an inflated feeling of pride in your superiority to others with a psyche that is conscious and most immediately controls thought and behavior being in touch with external reality. It is an exaggerated sense of self-importance; conceit. There is only one indirect reference in AGGS with admonishment to Brahmins following Vedas/Vedanta for such sacrifices for the sake of Ego.

ਬ੍ਰਹਮਣ ਕੈਲੀ ਘਾਤੁ ਕੰਞਕਾ ਅਣਚਾਰੀ ਕਾ ਧਾਨੁ ॥ਫਿਟਕ ਫਿਟਕਾ ਕੋੜੁ ਬਦੀਆ ਸਦਾ ਸਦਾ ਅਭਿਮਾਨੁ ॥

Barahmaṇ kailī gẖāṯ kañkā aṇcẖārī kā ḏẖān.Fitak fitkā koṛ baḏī­ā saḏā saḏā abẖimān.

If a Brahmin kills a cow or a female infant, and accepts the offerings of an evil person, he is cursed with the leprosy of curses and criticism; he is forever and ever filled with egotistical pride.-----Guru Amardas, Sloke Vaaran Tay Vadheek, AGGS, Page, 1413-4 & 5

Pride is the basic breeder of most human difficulties, the chief block to progress. When the satisfaction of our lower instincts, security and a place in society becomes the primary object of our lives, than pride steps in to justify our excesses. Fullness of knowledge always and necessarily means some understanding of our ignorance that is always conducive to both humility and reverence. Plenty of people wish to become devout but no one wishes to be humble.

ਇਕਨਾ ਨੋ ਸਭ ਸੋਝੀ ਆਈ ਇਕਿ ਫਿਰਦੇ ਵੇਪਰਵਾਹਾ ॥ਅਮਲ ਜਿ ਕੀਤਿਆ ਦੁਨੀ ਵਿਚਿ ਸੇ ਦਰਗਹ ਓਗਾਹਾ ॥

Iknā no sabẖ sojẖī ā­ī ik firḏė vėparvāhā.Amal je kīṯi­ā ḏunī vicẖ sė ḏargeh ohāgā.

Some understand this completely, while others wander around carelessly. Those actions, which are done in this world, shall be examined in the Court of the God.-----Sloke Sheikh Farid, 98, AGGS, Page, 1383-3

Spiritual ignorance is a very serious matter. It is said that "What you don't know won't hurt you". We all know that is incorrect and yet it seems that many people have adopted that philosophy toward spiritual matters. "Many people are destroyed for lack of spiritual knowledge". It is not merely the lack of knowledge, but self-destructive turning away from truth in all areas of life and to be ignorant of one's ignorance is the malady of the ignorant. It is the shore less ocean of darkness. It further leads to attachment with Maya.
Reference:: Sikh Philosophy Network http://www.sikhphilosophy.net/sikh-sikhi-sikhism/26553-gurbani-a-sikh-solution-female-feticide.html

ਅਸੰਖ ਮੂਰਖ ਅੰਧ ਘੋਰ ॥

Asankh Moorkh Andh Ghor.

Countless fools are blinded by ignorance.-----Japji, AGGS, Page, 4-3

Ignorance is the absence of the divine knowledge of perception which gives us the sight of the supramental Truth; it is the non-perceiving principle on our consciousness as opposed to the truth-perceiving conscious vision and knowledge. Ignorance is a self-limiting Knowledge confined to an exclusive concentration of in a single field. The Ignorance, though in Matter and Life, has its primacy in the nature of the Mind, which measures, limits, particularizes, and divides. But Mind also is a universal principle, of the “Supreme” with the tendency to unify and universalize. Mind becomes ignorant when it loses connection with the Absolute Principle. Individuals worshiping departed heroes, ancestors, etc is of no avail and is in utter spiritual ignorance.

Conclusion;
Reference:: Sikh Philosophy Network http://www.sikhphilosophy.net/showthread.php?t=26553

Spiritual ignorance is the origin and nature of error, falsehood, wrong and evil in the consciousness and will of the individual; a limited consciousness growing out of the nescience is the source of the error, a personal attachment to the limitation and the error born of it the source of the falsity, a wrong consciousness governed by the life-ego the source of evil. The spiritual ignorance referred here is not lack of information but a deep seated misperception of reality. The same is true about not accepting the females equal to man against the principles of AGGS. Divine Knowledge is the awareness and understanding of facts, truths or information gained in the form of learning. The purpose of Divine knowledge is to find the Truth and develop inner cleanliness by subjugating animal instincts and developing godly instincts or virtues by respecting human life and spiritual progress.

Virinder S. Grewal