I think there are some misconceptions regarding sin and it's consequences.Here are some scriptures. 
2Sa 12:13 
And David said unto Nathan, I have sinned against the LORD. And Nathan said unto David, The LORD also hath put away thy sin; thou shalt not die. 
Howbeit, because by this deed thou hast given great occasion to the enemies of the LORD to blaspheme, the child also that is born unto thee shall surely die. 
Because of David's adultery, murder, the LORD killed the child. 
Hos 1:2 
The beginning of the word of the LORD by Hosea. And the LORD said to Hosea, Go, take unto thee a wife of whoredoms and children of whoredoms: for the land hath committed great whoredom, departing from the LORD. 
And I will not have mercy upon her children; for they be the children of whoredoms.( fornication, adultery, prostitution ) 
Here again , no mercy upon the children.Why do the children suffer for the sins of the fathers? 
Ps.109.1 (To the chief Musician, A Psalm of David.) Hold not thy peace, O God of my praise; 
2 For the mouth of the wicked and the mouth of the deceitful are opened against me: they have spoken against me with a lying tongue. 
3 They compassed me about also with words of hatred; and fought against me without a cause. 
4 For my love they are my adversaries: but I give myself unto prayer. 
5 And they have rewarded me evil for good, and hatred for my love. 
6 Set thou a wicked man over him: and let Satan stand at his right hand. 
7 When he shall be judged, let him be condemned: and let his prayer become sin. 
8 Let his days be few; and let another take his office. 
9 Let his children be fatherless, and his wife a widow. 
10 Let his children be continually vagabonds, and beg: let them seek their bread also out of their desolate places. 
11 Let the extortioner catch all that he hath; and let the strangers spoil his labour. 
12 Let there be none to extend mercy unto him: neither let there be any to favour his fatherless children. 
13 Let his posterity be cut off; and in the generation following let their name be blotted out. 
14 Let the iniquity of his fathers be remembered with the LORD; and let not the sin of his mother be blotted out. 
15 Let them be before the LORD continually, that he may cut off the memory of them from the earth. 
16 Because that he remembered not to shew mercy, but persecuted the poor and needy man, that he might even slay the broken in heart. 
Deu 23:2 
ΒΆ 
A bastard (conceived out of wedlock)shall not enter into the congregation of the LORD; even to his tenth generation shall he not enter into the congregation of the LORD. 
Here is a curse pronounced of the LORD that an illegitimate child
could not enter the congregation nor his children up to 10 generations! Indeed these are serious consequences. 
Jer 14:20 
We acknowledge, O LORD, our wickedness, and the iniquity of our fathers: for we have sinned against thee. 
Do not abhor us, for thy name's sake, do not disgrace the throne of thy glory: remember, break not thy covenant with us. 
As believers in Christ we are in covenant with the LORD. We confess our sin of fornication, repent. The curse is under the BLOOD OF JESUS. We are delivered.Please do not put together our sinless Savior's birth with prostitutes and say" it is no big deal." By doing so the author ( I hope ignorantly ) is siding with devils that corrupt the word of God to deceive the elect. 
Rev.2.20 Notwithstanding I have a few things against thee, because thou sufferest that woman Jezebel, which calleth herself a prophetess, to teach and to seduce my servants to commit fornication, and to eat things sacrificed unto idols. 
21 And I gave her space to repent of her fornication; and she repented not. 
22 Behold, I will cast her into a bed, and them that commit adultery with her into great tribulation, except they repent of their deeds. 
23 And I will kill her children with death; and all the churches shall know that I am he which searcheth the reins and hearts: and I will give unto every one of you according to your works. 
24 But unto you I say, and unto the rest in Thyatira, as many as have not this doctrine, and which have not known the depths of Satan, as they speak; I will put upon you none other burden. 
25 But that which ye have already hold fast till I come. 
www.eternalvaluesministries.com HIs servant, Peter  
https://www.care-net.org/churches-blog/brothers-and-sisters-unwed-pregnancy-is-not-a-sin?success=true