Just heard a brief snippet on 'Women's Hour' (daily prog. on UK's Radio 4 -
the 'serious' station).  A trichologist described how a thyroid problem can
change hair characteristic: apparently, an underactive thyroid can lead to
weight gain - and fat accummulation (in the scalp?!) around the hair
follicule can somehow change the characteristic of the follicule causing
the hair to 'stick out' (appear curlier?).  Presuming this is reversible
(and I wasn't listening very closely since I was washing dishes at the
time) then maybe the hair changes noted around pregnancy and breastfeeding
may be contributable, in part, to the changes in thyroid action/weight
changes during these years.

Yours, with curly hair before, during and after three babies -
Hannah Hulme Hunter
National Childbirth Trust breastfeeding counsellor, UK

PS  A short article in the 'Sunday Times' at the weekend (serious
broadsheet newspaper) referred to artificial milk (formula/babymilk
substitute) as "factory milk".  Puts it in its place, doesn't it?