THE RISKS: More women are having their babies later in life than ever before but every extra year carries more risks for mother and baby
The number of babies born to women aged 35 and over rose by 58 per cent in the Eastern Regional Health Authority between 1993 and 2001.
Nationally, the number of women giving birth to their first child between the ages of 40 and 44 more than doubled between 1997 and 2002. These statistics fit into a general trend among women of having babies later. However, the number of babies born to older women is still a small percentage of the overall births with less than 15 per cent of all first-time mothers over 35 in 2002.
Obstetricians are keen to point out to women that the biggest risk factor associated with leaving it later to have babies is the risk of not being able to conceive.
"Declining fertility is a huge factor once a woman reaches 35. And at 38, the chances of getting pregnant even with in vitro fertilisation are 10 per cent," explains Dr Mary Wingfield, consultant obstetrician/gynaecologist at the National Maternity Hospital, Dublin and director of the Merrion Fertility Clinic.
"The risk of miscarriage also goes up as women get older, rising from a risk of one in five to one in three pregnancies resulting in miscarriage for women over 40.
"The risks of having a baby with a chromosomal abnormality also increases with age," adds Dr Wingfield.
"It is thought that about a third of women's eggs at the age of 35 have a defect but that up to a fifth of Down syndrome may be the result of a sperm defect," writes Gill Thorn in Not Too Late - having a baby after 35 (Practical Parenting).
In her book, Thorn presents a table of the age-related risk of major chromosomal defects which states the risk at 35 years of age to be one in 335, rising to one in 100 at age 40 and one in 25 at age 45.
Another more recent study places the risk of a woman of 35 having a baby with any chromosomal abnormality at one in 192, at 40 years her risk increases to one in 68 and at 44, one in 26.
During pregnancy itself, older mothers are at a higher risk of having high blood pressure and diabetes, according to Dr Wingfield. However, the risks of post-natal depression don't appear to be specific to age or number of previous children.
"Factors which may increase a mother's risk of postnatal depression are an emergency delivery, a past history of depression, poor relationship with her partner, low self-esteem, low socio-economic status, low social support, stressful life events and an unwanted pregnancy," says Declan Devane, midwifery research assistant at the School of Nursing and Midwifery Studies, Trinity College Dublin.