Steroid injections at 38 weeks

So today I had a consultation with my doc, who has booked me for my 3rd section. He recommends i go in at 38 weeks to avoid going into labour naturally before. But has said that steroid injections will be offered 2 days before to help babies lungs mature. He told me the risks of these injections, some are life long, learning development issues in school, behavioural etc. Which is not something anyone would want for their children. Why are they offering it to me when 38 weeks in considered term? My 2nd baby came at 38 weeks and was absolutely fine, my sister can’t go past 37 weeks and naturally goes into labour, all her kids are fine, no breathing issues.

If anyone has any info or opinions, that’d be great before I make a decision