Women who suffer extreme morning sickness may be less likely to give birth to sons.
Hyperemesis gravidarum (HG) involves severe vomiting – sometimes up to 50 times a day – and its causes are unknown. Kate Middleton suffered from it during both of her pregnancies. Now a study of 1.65 million pregnancies in Sweden has found that less well-educated women are more likely to develop HG, and that women who develop HG are more likely to have daughters.
