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Fruit & veg cut risk of small baby

SGA risk rises with poor diet pre-pregnancy, smoking and vigorous exercise

Louise Prime

Friday, 08 October 2010

Women who eat enough fresh fruit and leafy green vegetables in the 3 months before pregnancy are less likely to have a small-for-gestational-age (SGA) baby, research has shown. Factors that increase the risk of normotensive mothers having an SGA baby include smoking beyond 15 weeks of pregnancy and vigorous daily exercise during pregnancy.

Researchers, writing in BJOG: An International Journal of Obstetrics and Gynaecology say their findings increase the pressure for public health interventions to reduce the risks to babies’ health.

Their SCOPE (Screening for Pregnancy Endpoints) study followed 3513 women expecting their first baby, and looked for factors that influenced the likelihood of the baby being born SGA. The study authors collected data on the mothers’ birthweight, age, gynaecological history, socioeconomic status, diet, lifestyle, alcohol consumption and smoking habit. They took fetal measurements and performed Doppler ultrasound of the umbilical and uterine arteries at 20 ± 1 weeks.

Women were divided into two groups for analysis, according to whether or not they had hypertension in late pregnancy.

Hypertensive women were at greater risk of having an SGA baby if they had conceived by IVF or had previously suffered an early pregnancy loss.

Normotensive women who had eaten more than three portions a day of leafy green vegetables in the three months before conception were half (50%) as likely to have an SGA baby; and women who had eaten fruit less than once a week were 50% more likely to have an SGA baby. Women who ate at least three portions a week of oily fish were 60% less likely to have an SGA baby. The authors point out that a diet high in fruit, vegetables and fish is often associated with other healthy lifestyle choices.

Their earlier work had already revealed that maternal smoking before 15 weeks’ pregnancy did not increase the risk of an SGA baby. Their current research showed that after 15 weeks, the risk of having an SGA baby increased by 30-60% for every five cigarettes smoked daily.

Other factors that increased SGA risk included daily vigorous exercise, being a tertiary student, increasing maternal age and the woman having been a small baby herself.

The authors suggest that pregnancy, and where possible prior to the pregnancy, may well be the ideal times to encourage women to adopt a healthy diet, improve their intake of important nutrients, and make lifestyle changes to reduce their risk of obesity.

Lead author Professor Lesley McCowan from the University of Auckland said: “SGA infants are more likely to be stillborn, to have complications in the newborn period and in later life. Less than one third of these at-risk babies are identified before birth in current antenatal practice.

“Improved identification of these vulnerable infants, by screening early in pregnancy, therefore has the potential to reduce stillbirths and complications in the newborn period.”      

BJOG’s editor-in-chief Professor Philip Steer said: “This study emphasises the importance of good diet and nutrition. Unfortunately, many people find it difficult to resist the temptations of ‘junk’ food.

“If more women can be persuaded to have a better diet during pregnancy, using the motivation of optimising their baby’s health, then as they are commonly in charge of the family diet, we could improve the health of the whole population.  The take-home message is: fewer take-aways, more fresh fruit and vegetables.”

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