Assisted reproductive technology and the risk of preterm birth among primiparas

Singletons born to primiparous women using assisted reproductive technology had increased risk for preterm birth compared with those conceived spontaneously. The increased risk was observed along the gestational age continuum.

Galit Levi Dunietz, M.A., M.P.H., Claudia Holzman, Ph.D., D.V.M., Patricia McKane, M.P.H., D.V.M., Chenxi Li, Ph.D., Sheree L. Boulet, Dr.P.H., David Todem, Ph.D., Dmitry M. Kissin, M.D., M.P.H., Glenn Copeland, M.B.A., Dana Bernson, M.P.H., William M. Sappenfield, M.D., Michael P. Diamond, M.D.

Volume 103, Issue 4, Pages 974-979


To investigate the risk of preterm birth among liveborn singletons to primiparas who conceived with assisted reproductive technology (ART) using four mutually exclusive categories of infertility (female infertility only, male infertility only, female and male infertility, and unexplained infertility) and to examine preterm birth risk along the gestational age continuum.

Retrospective cohort study.

Michigan (2000–2009), Massachusetts and Florida (2000–2010).

Singletons born to primiparas who conceived with or without ART.


Main Outcome Measure(s):
Preterm (

For the male infertility only, female infertility only, combined male and female infertility, and unexplained infertility groups, ART-conceived singletons were significantly more likely than non-ART singletons to be born preterm: adjusted odds ratio (aOR) 1.24 (95% CI, 1.13, 1.37), aOR 1.60 (95% CI, 1.50, 1.70), aOR 1.49 (95% CI, 1.35, 1.64), and aOR 1.26 (1.12, 1.43) respectively. Among infants whose mothers were diagnosed with infertility, the odds of preterm birth were highest between 28–30 weeks [female infertility only, aOR 1.95 (95% CI, 1.59, 2.39); male and female infertility: 2.21 (95% CI, 1.62, 3.00)] compared with infants in the general population. Within the ART population, singletons of couples with female infertility only were more likely to be born preterm than singletons born to couples with other infertility diagnoses.

Among singleton births to primiparas, those conceived with ART had an increased risk for preterm birth, even when only the male partner had been diagnosed with infertility. The risk of preterm birth for ART-conceived infants whose mothers were diagnosed with infertility included the earliest deliveries.

  • Galit Dunietz

    Thank you for your comment. Unfortunately, our data include only “successful” ART cycles that resulted in live birth. We have in our dataset women who gave birth more than once, ART and non-ART conceived pregnancies. I can look into that, but I suspect that given the rarity of PTB, we would end up with small number of observations and insufficient statistical power for the analysis.

  • Amanda N. Kallen

    Thanks to the authors for a very interesting study. Is there any possibility of looking at risk of PTB in patients who underwent ART unsuccessfully and then conceived spontaneously? I think this would be an interesting way of looking further into whether the increased risk is inherent to the history of infertility itself or related to the stimulation method.

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