Unfortunately, having HG in one pregnancy puts you at a higher risk of suffering in subsequent pregnancies (Fejzo et al 2011) although it is possible to escape it. Some women ﬁnd that the HG gets better in subsequent pregnancies, whereas others ﬁnd it stays the same or gets worse. There is really no way of knowing how your pregnancies will relate to each other. If you have had HG it is a good idea to prepare for it in subsequent pregnancies. It's better to be prepared and not suffer it, than to cross your fingers and hope you won't get it then get caught out.
Information for women contemplating another pregnancy can be seen at HER foundation Trying Again There is a series of questions for you to ask yourself to help you consider all the issues.
It is possible to still have HG but have a better experience than first time round if you start medication pre-emptively. For this, you will have to have a co-operative GP and/or consultant. Most hospitals should offer pre-pregnancy counselling where you can discuss your care and satisfy yourself that you will have every possible treatment should you need it. For evidence that pre-emptive treatment works see Koren 2010 Pre-emptive treatment HG and Maltepe 2013 Preemptive Diclectin
Pregnancy Sickness Support have documents which you can download and use as a template to write your own pre-pregnancy plan with your doctor PSS Trying Again
Fejzo MS, MacGibbon KW, Romero R, Goodwin TM, Mullin PM. Recurrence Risk of Hyperemesis Gravidarum. J Midwifery Women Health. 2011 Mar-Apr;56(2):132-6.