[Spoilers!] First chapter of PT

[didymos]

In that situation and due to STD it is more than probable than Thomas is effectively using condoms everytime, as it is the best shield for STD transmission.

While he may have been using condoms, it wasn't for fear of STDs.  White Court vamps aren't really vulnerable to them:

“Microorganisms aren’t a problem to my kind,” Thomas said. “As long as I don’t bleed out, I’ll be fine.”

Butcher, Jim. Cold Days (The Dresden Files, Book 14) (p. 286). Penguin Publishing Group. Kindle Edition.

[g33k]

While he may have been using condoms, it wasn't for fear of STDs.  White Court vamps aren't really vulnerable to them:

But they could become asymptomatic reservoirs.

We don't know.

I infer that it doesn't happen, because if the STD's of various kind WERE able to host inside a Whamp body, they'd become (because of their lifestyles) super-infectors (of all STD's... ever).  Like the STD versions of the uber-plague Nic tried to initiate.  And if THAT were to happen (a) all their prettiest pets would get infected and poxy and icky; (b) they'd have effective bioweapons to use against the White Council (infect their near and dear).

But again, we're getting into some inferred things; I don't think WoJ has delved deeply into supernatural STD's.

[Dina]

While he may have been using condoms, it wasn't for fear of STDs.  White Court vamps aren't really vulnerable to them:

But Justine is.

Nevertheless, g33k makes a good point. If they could transmit the diseases, they would infect their human pets. So probably they directly kill the microorganisms.

[Bad Alias]

The way Thomas and Justine operate, I'd say there's a fair chance his anti std mojo would be insufficiently aggressive to protect Justine in all cases if they were careless.

[Mira]

I mean, if Thomas said they took precaution we don't have any reason to believe he is lying, so it is more probable that it is true. Perhaps Justine lied to him, but in any case, he tried to take care, so at least he thought on that. Anyway, there are many differences with Harry's case. Harry was somehow until the influence of rampire spit and it was a "hot of the moment" thing, while Thomas and Justine are an stable couple that have a lot of sex on a regular basis, so of course they had time to thought about babies and making plans. But that is not all. IIRC due to the need to break the True Love thing and be able to have sex with each other they need to have sex with other partners. In that situation and due to STD it is more than probable than Thomas is effectively using condoms everytime, as it is the best shield for STD transmission.

I agree, but if he were, she shouldn't have gotten pregnant.  I just looked it up, apparently there is a one in fourteen chance of failure with condoms.  That whole paragraph is kind of weird though.  On what did Thomas base his notion that he was basically sterile?  If he believed that, other than fear of STD transmission why use a condom every time?  I still think that was the original bases for Lord Raith's power, he could reproduce where the rest couldn't.  Thinking back though the series, the White Court seemed to consist of families, and they were all related some how and rather small in number.  Remember the gathering where Toot's friends were enslaved and used as living lamps and Harry freed them?  If I remember correctly it was a gathering of all the clans and it only amounted to a hundred or so.  Lara hires vanilla humans as her muscle and guards, why when given their power and strength White Court Vamps would be much more effective.  Unless there aren't enough of them to do that.

[didymos]

If I remember correctly it was a gathering of all the clans and it only amounted to a hundred or so. 

It was the three major houses: Raith, Malvora, and Skavis.  It's implied there are also some minor houses that haven't been named:

“It’s one of the greater Houses of the White Court,” I said, nodding. “Raith, Skavis, and Malvora are the big three.”

Butcher, Jim. White Night (The Dresden Files, Book 9) . Penguin Publishing Group. Kindle Edition.

As to the number of vamps there:

We entered the cavern and found it packed with pale and startled beings, the entire place a wash of beautiful faces and gorgeous wardrobes—except for twenty feet around the entrance, where everyone had hurried away from the blazing herald of our presence.

Butcher, Jim. White Night (The Dresden Files, Book 9) . Penguin Publishing Group. Kindle Edition.

We then get a number on how many are seated, and that is about a hundred:

Furniture had been arranged in three large groupings, with a large open space in the center of the floor, and they were occupied by what I could only presume were the leading members of the three major Houses—somewhere near a hundred vampires in all.

Butcher, Jim. White Night (The Dresden Files, Book 9) . Penguin Publishing Group. Kindle Edition.

There's some ambiguity there.  It may have been only a hundred total after all, or there may have been some vamps standing instead of sitting.  In any case, most of them were only the "leading members of the three major Houses", which would mean there were a bunch of Whites who weren't in attendance.

[Bad Alias]

I agree, but if he were, she shouldn't have gotten pregnant.

He did. She did.

[Mira]

There's some ambiguity there.  It may have been only a hundred total after all, or there may have been some vamps standing instead of sitting.  In any case, most of them were only the "leading members of the three major Houses", which would mean there were a bunch of Whites who weren't in attendance.

Or in reality, there are not that many White Court Vamps..  Consider, they feed on emotion, sex is part of that, often until death if it goes that far..  So either there should be a lot of them, creating babies as they feed, or not that many because they are mostly sterile, and if they have sex it usually ends in death for the partner.   Say only Lord Raith is fertile in his House, he has had more than one wife in his long lifetime, while he only fathered one with Margaret, we don't know how many he fathered by his other wives, that adds up over the centuries.  Especially unless killed vamps live a very very long time. 

[morriswalters]

Since they speak ancient whatever, assume 2000 years.  Assuming one partner a day times 3000 years. And then every time he beats the odds he creates a new potential breeder, assuming it breaks towards males.  So over time it adds up.  It looks like Lara's demon would consider a fetus as a competitor and kill it. So no baby Lara's.  On the other hand Wraith's strategy of killing male children is a birth control strategy in and of itself.  Thomas speaks to that point.

Certainly the same strategy that the Whites tried against the wizards would make a nasty suspicious mind like mine think in those same terms about the Whites. And if my guess was right it would be open season on the males of the White Vampires.  You know, sauce for the goose so to speak.

[Bad Alias]

Vittorio Malvora was the son of Cesarina Malvora according to the wiki. https://dresdenfiles.fandom.com/wiki/Vittorio_Malvora. That was my recollection.

So either there should be a lot of them, creating babies as they feed, or not that many because they are mostly sterile.

There's no reason it can't be somewhere in between "a lot" and "not that many."

if they have sex it usually ends in death for the partner.

Uhm ... no it doesn't.

Say only Lord Raith is fertile in his House. 

He isn't. There's old whats his name from Bigfoot on Campus.

[Mira]

Uhm ... no it doesn't.

Um, unless there is very good control, yes, it does..  This is how Lord Raith entrapped his kids, set them up so they kill their first sex partner.  However you are making my point, since this is how they feed, there should be a lot of little WCvamps running around, and there are not..

He isn't. There's old whats his name from Bigfoot on Campus.

Refresh me, the memory is vague, but was the talk about sex or reproduction?

Vittorio Malvora was the son of Cesarina Malvora according to the wiki. https://dresdenfiles.fandom.com/wiki/Vittorio_Malvora. That was my recollection.

Again, she was the head of that House, she might be the fertile one..

[g33k]

... He isn't. There's old whats his name from Bigfoot on Campus.

Also Madeline & Madrigal's father wasn't Lord Raith (their papa departed from an aircraft without a parachute).

Given that they're millenia-old sex-centric vamps, I think the sheer lack of numbers, and few instances of parentage, speaks to their low fertility.

OTOH, we have Thomas & Inari -- two of Papa Raith's kids born relatively close together (only 15ish years apart, I think; and SHE was born deep into Margaret's death-curse against Papa-Raith).  That would be a breeding rate of about 7 kids per century (so I suspect it was anomalous).

If we presume rough equality of M/F births, and taking the WoJ rough estimate that there were 9-10 Raith sisters (including Lara & Inari) that looks like 20ish offspring, all told.

That's a pretty low fertility... but NOT what I'd call "all but infertile" (which was how Thomas described it in the Ch.1 excerpt).

[g33k]

... Refresh me, the memory is vague, but was the talk about sex or reproduction? ...

There was a young white-court-virgin Raith proto-vamp.  She WASN'T papa Raith's; she had a different daddy in the story.

[didymos]

This is how Lord Raith entrapped his kids, set them up so they kill their first sex partner. 

First feedings are always fatal.  The subsequent ones don't have to be.

[Bad Alias]

Um, unless there is very good control, yes, it does..  This is how Lord Raith entrapped his kids, set them up so they kill their first sex partner.

That wasn't the point you made or the one I responded to. You said a feeding usually ends in death. It doesn't. You're wrong. I seldom speak in such certainty on this forum because most things are speculative or there is at least an argument for it. You're simply asserting things that are contrary to the text with zero supporting arguments or evidence. You're just making stuff up. Which is fine. That's just headcanon or fan fiction. That's fine. I just think it's silly to suggest that one's headcanon or fan fiction is canon, unless the headcanon has some support somewhere.

However you are making my point, since this is how they feed, there should be a lot of little WCvamps running around, and there are not.

There are a lot of WCvamps running around. Enough to constitute a supernatural nation with major figures from major houses. With such distinctions being made, there are likely minor figures from major houses and minor houses with respectively major and minor figures.

Refresh me, the memory is vague, but was the talk about sex or reproduction?

I honestly have no idea what point you're trying to make. Whats his name from House Raith had a daughter. He wasn't Lord Raith. Sex is an integral part of any creature that reproduces through sexual reproduction.

Again, she was the head of that House, she might be the fertile one..

Morris suggested that all female Whites could be completely infertile. That was what I was responding to. I thought that was clear. Lady Malvora wasn't completely infertile. Therefore all female Whites are not completely infertile.

There was a young white-court-virgin Raith proto-vamp.

She wasn't neither a proto-vamp nor a virgin. That's kinda the point of the story. Not that it's germane to the current argument.