There was one maternal death in Dublin's Coombe Hospital in 2013, according to its newly published annual report.
The woman had a cardiac arrest and had been suffering from hyperkalaemia, a potentially life-threatening metabolic problem caused by the inability of kidneys to excrete potassium.
Hospital master Dr Sharon Sheehan said the complexity of cases, including both mothers and babies, was continuing to increase.
The hospital saw the rate of severe illness in women rise from 4.4 per 1,000 to 5.8 per 1,000, she said.
The main complication is massive obstetric haemorrhage, although the number of hysterectomies which had to be performed within 24 hours of delivery was low.
Some 180 women had to be admitted to the high dependency unit and 37.2pc of these were due to haemorrhage, with more than one in four related to high blood pressure. Four mothers were transferred to the intensive care unit in St James's Hospital.
The caesarean section rate in the hospital was 28pc and one in three babies were induced.
The perinatal mortality rate - baby deaths at or around the time of birth - was 4.66 when corrected for infants born with severe birth defects.
One in three women were from outside the Republic and more than a fifth were unemployed.
Communication difficulties were reported in 7.8pc of mothers at booking - the highest in seven years.
Around 5.7pc were over 40, the highest in seven years. One in three pregnancies was unplanned and just 56.6pc had taken folic acid, which can reduce the risk of spina bifida. The report said one in eight were current smokers, compared with 17.3pc in 2007.
There was a fall in the numbers of pregnant women drinking alcohol - down to 1.4pc compared with 3.5pc in 2010.
The report said nearly one in five mothers had a history of psychological or psychiatric disorders - the highest in seven years - including 4pc with a history of post-natal depression.
At booking, just over half (51.6pc) were in the healthy weight range, 2.1pc were underweight and 28.9pc were defined as overweight. Overall, 17.1pc were obese and 1.8pc were classed as morbidly obese.
Around 12.6pc had history of one previous caesarean section at booking and 3.4pc had two or more caesarean sections previously, according to the statistics.
There were 195 multiple pregnancies looked after in the hospital during the year with 188 sets of twins, six sets of triplets and one set of quads.
The report noted the steady increase in the number of gynaecological surgeries carried out. The Coombe saw an increase in births last year along with other Dublin hospitals.