Does assisted reproduction technology, per se, increase the risk of preterm birth?
Article first published online: 19 DEC 2006
BJOG: An International Journal of Obstetrics & Gynaecology
Special Issue: Reducing the Burden of Prematurity: New Advances and Practical Challenges
Volume 113, Issue Supplement s3, pages 68–71, December 2006
How to Cite
Blickstein, I. (2006), Does assisted reproduction technology, per se, increase the risk of preterm birth?. BJOG: An International Journal of Obstetrics & Gynaecology, 113: 68–71. doi: 10.1111/j.1471-0528.2006.01126.x
- Issue published online: 19 DEC 2006
- Article first published online: 19 DEC 2006
- Accepted 8 September 2006.
- Assisted reproduction;
- multiple pregnancy;
- preterm birth;
- singleton pregnancy
There is little doubt that all methods of assisted reproduction increase the likelihood of multiple pregnancy and, as a result, increase the likelihood of preterm birth. Data from the East Flanders Prospective Twin Study clearly show that the proportion of spontaneous to iatrogenic twins has changed from 25:1 to 1:1 over the past two decades. Data from the very low birthweight (VLBW) Infant Database of the Israel Neonatal Network showed that 10% of VLBW singletons were a result of assisted reproduction compared with 60% of the VLBW twins and 90% of the VLBW triplets. Irrespective of plurality, an association between preterm birth and assisted reproduction has long been suspected and was related to causes such as iatrogenic preterm birth (in the so-called ‘premium’ pregnancies), fertility history, past obstetric performance and to underlying medical conditions of the female partner. With more data available, a clearer picture is defined. Two different, recent meta-analyses showed that singleton pregnancies resulting from in vitro fertilisation (IVF) have increased rates of preterm birth at <33 weeks of gestation (OR 2.99; 95% CI 1.54–5.80), at <37 weeks of gestation (OR 1.93; 95% CI 1.36–2.74) and a relative risk of 1.98 (95% CI 1.77–2.22) for preterm birth in singleton pregnancies resulting from in vitro fertilisation embryo transfer/gamete intra fallopian transfer (IVF-ET/GIFT) compared with naturally conceived pregnancies. Since there is no way to predict which pregnant woman is at increased risk of preterm birth, it may be advisable to consider all pregnancies after assisted reproduction as being at risk. In any case, the most appropriate endpoint after assisted reproduction should also include preterm or term birth as measure of success.