Birth Risks Of Assisted Fertilization Linked To Infertility Causes Rather Than Procedure

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Main Category: Pregnancy / Obstetrics
Also Included In: Women's Health / Gynecology;  Pediatrics / Children's Health
Article Date: 01 Aug 2008 - 0:00 PST

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The adverse perinatal outcomes associated with assisted fertilization (AF) in comparison to infants conceived spontaneously could be associated with the causes of infertility rather than the procedure itself, according to an article released July 31, 2008 in The Lancet.

Increasingly, women in developing countries are delaying childbirth until an age when fertilization is decreased. As a result, more and more are turning to assisted reproductive technologies to achieve pregnancy. Assisted fertilization has been associated with an increased risk of adverse health outcomes in infants, but it is difficult to separate the effects of the procedure itself from those that might simply be inherent in the birthing couple.

To help differentiate between these two effects, Dr Liv Bente Romundstad, St Olav's University Hospital, and Department of Public Health, Norwegian University of Science and Technology, Trondheim, Norway, and colleagues performed a population-based cohort study, selecting women over 20 who had at least one singleton pregnancy spontaneously as well as at least one after assisted fertilization. The infants were examined for birth weight, gestational age, the chances of low birth weight given gestational age, premature birth, and perinatal deaths from 2,546 Norwegian women older than 20. These results were compared with rates in 1,200,922 single birth controls and 8,229 AF controls.

It was found that AF conception was associated with:

• a lower average birth rate by 25 g
• a shorter gestation period by 2.0 days
• a 26% increased risk of being undersized for gestational age
• a 31% increased risk of perinatal death. 

In the women for whom factors other than AF were controlled, that is, the women who had conceived both spontaneously and by AF, the AF babies had:

• a lower average birth rate by 9 g
• a shorter gestation period by 0.6 days
• a similar risk of being undersized for gestational age
• a 200% increased risk of perinatal death. 

The authors summarize and conclude: "Birthweight, gestational age, and risks for small gestational age babies, and preterm delivery, did not differ among infants of women who had conceived both spontaneously and after assisted fertilisation. The adverse outcomes of assisted fertilisation that we noted compared with those in the general population could therefore be attributable to the factors leading to infertility, rather than to factors related to the reproductive technology."

Dr Anja Pinborg, Copenhagen University Hospital, Denmark, and colleagues, contributed an accompanying comment which states the importance of this research: "Considering that 14% of all newborns in Europe are conceived after assisted reproductive technology (ART), safety concerns are important. Reducing the number of multiple births has made improvements, but we need to gain a better biological understanding of the reasons why infertility and ovarian stimulation may have adverse effects on infant health. Consequently, we have to continuously monitor the short and long-term risks of ART."

Effects of technology or maternal factors on perinatal outcome after assisted fertilisation: a population-based cohort study
Liv Bente Romundstad, Pal R Romundstad, Arne Sunde,Vidar von During, Rolv Skjærven, David Gunnell, Lars J Vatten
Published Online Lancet July 31, 2008
DOI:10.1016/S0140-6736(08)61041-7
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Written by Anna Sophia McKenney
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