Pregnant women in their early 20s and after 40 have the highest risk of giving birth prematurely, according to new research.
Women who wait to have children between 30 and 34 are in the ‘sweet spot’ where their risk of preterm birth is the lowest – even lower than those who are most fertile in their 20s.
While women worldwide are increasingly giving birth later in life, the risk for preterm birth is also going up.
However, researchers continue to investigate the exact association between maternal age and premature birth.
A Canadian study found that pregnant women aged 40 and older are at the greatest risk of premature birth and those aged 30 to 34 are at the lowest risk
Researchers from Canada, analyzed data from 32 hospitals in Quebec from 2008 to 2011.
They examined 165,195 pregnancies and identified five different age groups among the participants.
Age groups ranged from 20 to 24, 25 to 29, 30 to 34, 35 to 29, and 40 years or more.
Researchers then compared the women based on maternal characteristics, gestation and complications at childbirth and risk factors for prematurity.
Their study published in the journal PLOS ONE noted the common risk factors that come along with a mature pregnancy.
Lead study author Dr Florent Fuchs, said: ‘Some of the known risk factors identified more commonly in older mothers, 40 and over, included placental praevia, gestational diabetes, medical history, use of assisted reproduction technologies and occurrence of an invasive procedure.’
He added that risk factors in younger mothers aged 30 and under included past drug use, smoking and never having given birth before.
‘Even after adjusting for confounding factors, we found that advanced maternal age – 40 or over – was associated with preterm birth,’ he said.
The results also showed that preterm birth was mainly spontaneous in younger women aged 20 to 24, whereas it was more frequent in women over 40.
Giving birth prematurely, before 37 weeks gestation, can cause serious health complications to the mother and permanent learning and development disabilities to the babies such as cerebral palsy.
Biologically, the best age to bear a child is between 18 and 35.
After 35 years old pregnancies are considered high risk, putting mothers in danger of developing gestational diabetes, high blood pressure and preclampsia.