Hyperemesis gravidarum (HG) is the medical name for severe sickness and vomiting during pregnancy. Only around 1% of pregnant women get HG, but the effects usually last longer than morning sickness.
If treated, HG should not harm your baby. However, if you're losing weight, there is a chance your baby could be born small.
Talk to your GP if you're losing weight, or have dizziness or dehydration.