MIDWIFE NIKKI SAYS: A large study in 2004 in Denmark showed that pregnant women who regularly work nights have an increased risk of late miscarriage or stillbirth, although other factors such as age, smoking habits and the physical demands of the job were also taken into account.
These results support other studies that show working night shifts when pregnant can slightly increase the risk of having a low birth-weight baby.
Some researchers also believe there is a link between regular night duty work during pregnancy and losing a baby due to increased oestrogen levels - exposure to light at night suppresses the normal night-time release of the sleep-related hormone melatonin, which in turn causes an increase in other hormones, including oestrogen.
A further smaller study, in the US state of North Carolina, stated that working nightshifts in the first three months of pregnancy doubled the risk of premature labour.
Therefore, according to these studies, it is advisable that you change to day shifts for the remainder of your pregnancy.
Most employers undertake a workplace risk assessment once you tell them you're pregnant, and one such risk factor is working night shifts.
Your employer must do whatever is reasonable to prevent such a risk and should offer you suitable alternative work. Ask, and you may be surprised at how flexible they will be.