The biggest maternal age group last year was 30-35, compared to 25-29 in previous years, according to the National Obstetric Information System report, published today.

33.2% of mothers were aged between 30 and 35.

"This is the first time since the establishment of the NOIS in 1999 that most deliveries occurred to mothers in the 30-35 age group, and this reflects the trend of increasing maternal age at delivery," the report says.

The report also shows that 2011 showed the highest percentage of deliveries to mothers of non-Maltese nationality, at 11.3%, the level having risen gradually from 4.5% in 2001.

Last year, 71.3% of mothers were married, 24.3% were single and 4.3% were widowed, separated or divorced..

There were 4,226 deliveries last year, an increase of 275 live births. There were 28 still births.

69 twins and seven triplets were delivered.

60.6% of all births were by vertex delivery while 35.2% were delivered by Caesarean Section ( up from 29% the previous year) and 4,3% by assisted vaginal delivery.

The death rate in foetuses 500g and over was 5.3/1000 total births in 2011. The neonatal mortality rate was 5.1/1000 live births and the perinatal mortality rate was 10.5/1000 live births.

There were no maternal deaths