Apparently, I am married to a squirrel or an ostrich. My wife is pregnant with our second child, and from the marketing viewpoint pregnant women come in two categories. Squirrels seek out and hoard information on maternity and baby products from many sources and make up their own minds; ostriches rely on medical professionals and think, 'they'll tell me what I need to know' and obediently follow their advice.

I am not sure what animal characteristics the industry uses to categorise husbands of pregnant women. But I recently acted the squirrel and added to my information collection on baby products, or at least the techniques used to persuade me to buy them, at a conference on marketing to pregnant women.

A few simple facts explain why everyone else was there. First-time parents spend, on average, pounds 1,150 on baby products in the first year. Given that there will be around 350,000 first-time mothers in 1994, it is a market well worth fighting for. Add 440,000 second-time or later parents, who spend lesser but still considerable sums. And don't forget that new families also spend highly on many non-baby products (they are particularly likely to move house and buy consumer durables).

The first lesson was that the 'new dad' does not exist. Men might be crucial to the big ticket items such as cots and prams, but they don't influence day-to-day purchases such as 'nappies, creams, lotions and potions', according to Mia Dickson of the marketing consultancy Tequila.

But a little knowledge is a dangerous thing, says Ms Dickson. 'Men get interested and become five-minute experts. One dad, after watching a TV programme on dehydrated baby foods and learning that some contained maltodextrin - also known as postage stamp glue - barged into the kitchen and threw out all the packet food, declaring that only freshly pureed vegetables were good enough for his baby. His wife ignored him and fished them all out of the bin the next day.'

It was no surprise that we had bought a camcorder when our son was born - a third of new camcorder sales are to pregnant women or their partners. And buying Cow & Gate food but not their milk is, I was told by the company's head of communications, nothing more than predictable middle-class purchasing behaviour.

Our household was also typical in our almost complete ignorance of baby brands prior to parenthood. I had no idea whether SMA was formula milk or the Society of Marine Artists, or whether Pampers were nappies or South American grasslands.

This widespread ignorance, combined with the desire to 'do their best' for their child, explains why pregnant mothers are easily influenced. Another is that the companies know the importance of getting in quick. The first brand tried has an enormous advantage. 'Mums are unwilling to move off a product that has proved successful,' according to Drusilla Gabbott of the advertising agency Abbott Mead Vickers. 'They will do almost anything not to disrupt their baby's routine.

'Many mothers stick to using the nappy cream brand which came in their bag of free samples, the shampoo recommended by their midwife, and the baby rice whose packet design first caught their eye in the supermarket.'

How to find out what you really need? For a start you could ask all your friends with children what they bought but never used - there's always something. Some mothers have collections of items which traditionally figure on baby lists - such as baby lotion - yet months after their children are born they have no idea what these lotions are really for, because no need for them has arisen. Among my friends' favourite examples of wasted money produced by my private research are baby towels, baby baths and breast pumps, down to smaller products like trainer cutlery and baby soap. There are no easy answers, but you are probably better off being a squirrel than an ostrich.