The NHS Cumbria report found a strong link between lifestyles and unsuccessful pregnancies.
One in five mothers reviewed for the report had a body mass index (BMI) of more than 35, and a third of the mothers smoked during pregnancy.
In comparison, from the general maternity population, around one in ten mothers have a BMI of more than 35 and one in six smoke throughout their pregnancy.
More top news
Spells of rain overnight will give way to a sunny day tomorrow.
Visitors to Bassenthwaite who haven't yet visited the lake's popular ospreys only have a few weeks left to see them up-close.
Two new primary schools in the Borders have welcomed pupils for the first time today, Wednesday 16 August.