Jonathan Tullett

Note: Please read the updates at the bottom of this post before commenting on the fundamental errors in the calculations :)

Deferentectomy (aka vasectomy): a word which will make a lot of men wince and possibly even cross their legs at the mere thought; a procedure I know a lot of men will not even consider, despite it being a far safer operation to tubal ligation (female sterilisation).

I’ll start by saying that I know I will want more children in the future. When this may be I do not know, but I want any decision to have a child to be mutual and for it to be a planned event; absolutely no ‘accidents’¹.

There are many different contraception types available to females, each, as with most things, having positive and negative points. A (non-exhaustive) list includes: a plethora of pills, Depo Provera injection, implant (eg. Implanon or Norplant II) devices, IUDs and even the (sexily named) Femidom (female condom).

There aren’t so many options for men. The only one which comes to mind is the condom (for the purposes of this post, I’m not including methods which are currently under going trial or are waiting to undergo trial as they’re not generally available.)

‘Typical use‘ failure rate for condoms is 0.12-0.18 (the Pearl Index currently has it at 0.15). ‘Perfect use’ is 0.02 but this is real life and I’m not perfect so we’ll go with 0.15.

(As this post meanders towards its ultimate ending, I base the rest on the fact it can’t be known for certain whether the female is on contraception and more importantly that it’s working effectively.)

On the basis that a female is fertile for up to 7 days out of a 28 day cycle², thus 0.25, and there’s a 0.15 failure rate in using condoms; and on the assumption that neither the male or female is aware of which day of the cycle she’s on (as fertility awareness can be used to determine the days additional contraception should be used, or sex abstained from), this gives the following calculation:

Risk of condom error:         0.15
Risk of female being fertile: 0.25 x
----------------------------
Risk of pregnancy:            0.0375

Or, 3.75%.

Or, 15%.
See update 1, below.

Thinking that over the course of a single year there’s a 15% chance of unexpected pregnancy and all that could entail – the trauma of abortion, the stress of an unexpected/unwanted pregnancy, cost etc – even when using condoms is enough to put me out of the mood completely. It’s making me consider a ‘temporary vasectomy‘³.

The main advantage of having a vasectomy, for this scenario, is, once it’s confirmed successful, there is only a typical failure rate (pregnancy) of 0.0015. Plugging this into the calculation above yields:

Risk of vasectomy leakage:    0.0015
Risk of female being fertile: 0.250 x
----------------------------
Risk of pregnancy:            0.000375


Or, 0.0375%. A far more reassuring figure (100x, in fact).

0.15% – a far more reassuring figure (100x, in fact).

The disadvantage of doing this is that vasovasostomy, although often a very successful operation, usually results in only 30-90% of the sperm returning to the ejaculate and chance of normal fertilisation drops to 30-60% (ignoring other potential female factors.)

Should the vasovasostomy fail, I’d have a back up stored in liquid nitrogen somewhere.

So, over all, the advantages are:

• Little to no chance of accidental pregnancy

The disadvantages are:

• Requires an operation to have children naturally
• Cost of the vasovasostomy is £1500-£3000
• Cost of IVF should the reversal fail
• Possibility of not being able to have children if both vasovasostomy and IVF fail
• Emotional stress and trauma to a relationship caused by going through the above
  options and possibly ultimately failing⁴

While, in numbers of positives and negatives, it appears to be a bad idea, the sheer weighting of the advantage at least levels the playing field, in my mind.

Some questions, however, which are arising:

1. Is this a bat-shit crazy idea?
2. If you’re female, what do you think about a guy taking such an active interest in contraception:
   1. If you know you want children?
   2. If you know you don’t want children?
3. If you’re male, is this something you’ve considered?
4. Is there anything glaringly obvious that I’ve missed here?

As you can see from the above, this isn’t something I’m considering lightly, or doing without researching facts and figures. But I am genuinely interested in others’ thoughts and feelings on this subject. Sarcastic or stupid responses will be deleted, everything else will be seriously considered and replied to. Ideally I’m looking for responses from both an emotional and logical POV, both male and female.

Thanks in advance.

Update 1:

An astute reader (thanks Rosie!) saw I’d misread the tables and there’s no need to multiply the condom failure rate with the female fertility – the 0.15 is the, and I quote, ‘chance of pregnancy during the first year of use‘.

15%!

Which still remains two orders of magnitude greater than having the vasectomy, which is 0.0015, or 0.15%.

This validates my train of thought even more.

Update 2:

I’m aware that combining contraceptive methods increases effectiveness (eg the implant + male condom is 99.99% effective), but I’m thinking of this from the purely male perspective/action plan point of view.

1. I quote the word ‘accident’ as I believe what most people call ‘accidental pregnancies’ would be better referred to as ‘unplanned’. The ‘accidents’, in my experience, are due to thoughtlessness or plain carelessness, eg, forgotten pills, antibiotics rendering pills useless, condoms breaking due to incorrect usage etc rather than a genuine accident. Perhaps this is pedantic semantics?
2. Yes, I used Wikipedia for my data. Yes, I know this isn’t a definitive source, but this isn’t a dissertation, so bite me.
3. A temporary vasectomy would be where you go for the operation with the intention of having a reversal later on.
4. My logical brain thinks if a relationship can’t cope with this stress, then you shouldn’t be having kids in the first place.