Acupuncture is a safe therapy which doesn't involve any drugs, so expectant mothers can have it throughout pregnancy without fear of any side effects. Generally it can boost your energy levels and help you sleep better.
More specifically, according to a doctor who conducted a study on effects of acupuncture, even one session can significantly reduce the severity of 'morning sickness'. It also helps relieve indigestion and heartburn during pregnancy.
In later stage of pregnancy, acupuncture can also be used to prepare women for labour and promote natural childbirth. Research shows that acupuncture have positive effects not only on the duration but also the efficiency of labour.
A group of women who received acupuncture on a weekly basis from week 36/37 onwards not only had a shorter time of labour on average, but also experienced less complications which required emergency medical interventions, compared to those who didn't have acupuncture during pregnancy.
Other conditions that can be treated with acupuncture:
Constipation
Carpal tunnel syndrome
Anxiety
Insomnia
Sinusitis
Oedema
Varicose veins
Breech babies
Induction
Articles on Acupuncture and Pregnancy/Fertility:
"Acupuncture Fights Morning Sickness" BBC News
"Acupuncture May Relieve Heartburn in Pregnancy" MedicineNet.com
Acupuncture "Pregnancy Pain Cure" BBC News, 18 March 2005
"Acupuncture & Exercise May Ease Polycystic Ovarian Syndrome" MedicineNet.com
"Acupuncture may help increase IVF success rates by 65%" The Guardian, 8 February 2008
"Acupressure Techniques for Pain Relief in Childbirth" Debra Betts' website