Sherbahn crunched the figures on almost 2,500 sessions of in-vitro fertilisation (IVF) carried out at his clinic over an eight-year period. Being thin can lower the sex hormone oestrogen, making it harder to get pregnant. Sherbahn said that while some other studies had hinted that being skinny may be worse for fertility than being fat, he was ‘surprised’ at the size of the effect.
