I’m very much on the side of “The Baby is David’s” because a show can get away with infidelity but when you start having babies dying, miscarriages, deaths of pregnant women, etc. you’re getting into non-family friendly territory and Sherlock is still a primetime family show.
Also there’s exactly 0% chance of anyone in this show legitimately raising a child that is just not happening.
While I’m not arguing with you about the possibility of David being the father, I wouldn’t call Sherlock a family show. It airs after the 9pm watershed, which is the time of day when programming in the UK officially becomes kid-unfriendly. It’s still primetime, but it’s generally accepted that parents rely on their own discretion from that point onward. Complaining that your seven-year-old was exposed to inappropriate material by watching, say, Happy Valley, wouldn’t be considered a valid grievance because that show went out after nine o’clock.
It’s true that Sherlock is a show that whole families (including mine) watch as a group, but I’d wager that that’s not true of families with young kids. Doctor Who is probably much closer to what you might consider a family show, and even that has gotten away with some pretty dark subject matter, especially in the RTD years.
Moreover, years and years of popular soaps have pushed the boundaries of what you can get away with in terms of family-unfriendly plot developments, both before and after the watershed. They’re no strangers to dead babies or shocking murders. Eastenders had a domestic abuse victim bludgeoning her husband with the business end of iron, Emmerdale crashed a plane into the village and killed several characters in one go and Corrie had an out-and-out serial killer a while back. When you look at some of the most controversial plotlines that have aired over the years (and especially in the context of the time periods they originally aired in), you can see that it would take quite a lot for the Sherlock creative team to devise something that might have executives hedging their bets about the sensitivity of the viewers, especially when the show has an overall darker tone than most soaps. They’ve already had the protagonist tortured, you can’t really get much more family-unfriendly than that.
The last thing I saw in straight drama that really stood out for me as being particularly shocking was probably the marital rape in The Politician’s Husband (and even then, that didn’t draw nearly as much controversy as I was expecting) so that gives you a bit of an idea of the parameters that Sherlock is working within in terms of the current viewing climate. With all this in mind, I definitely wouldn’t rule out killing Mary and/or the baby.
I completely agree with you about how the show just isn’t compatible with child-rearing. There’s a status quo to be maintained, one that allows Sherlock and John to carry on going out and solving cases, and that obviously doesn’t jive with raising a kid responsibly. I mean, I feel like John is less than thrilled at the prospect of becoming a dad, but I don’t think he’d go as far as to do a half-arsed job and end up being a negligent parent. He’d sooner see The Work suffer than the kid.