I’ve just read the paper. Interesting but I don’t think it’s lockdown related as they suggest.
The numbers are very small. Past few years 18-21-12-20-3. The three is very low but not outside the bounds of statistical variance (I’m guessing, as no error bars). If this is the same everywhere then all other nicus should be mostly empty too and they most definitely are not.
They compare rates jan-mar. But most pregnant women didn’t change their behaviour or external influences until March at the earliest.
Paper is here www.medrxiv.org/content/10.1101/2020.06.03.20121442v1.full.pdf