Adverse obstetric and perinatal outcomes of singleton pregnancies may be related to maternal factors associated with infertility rather than the type of assisted reproductive technology procedure…

Among singleton pregnancies, maternal factors associated with infertility, rather than the ART procedures themselves, may contribute to several obstetric and perinatal outcomes.

Masako Hayashi, M.D., Ph.D., Akihito Nakai, M.D., Ph.D., Shoji Satoh, M.D., Ph.D., Yoshio Matsuda, M.D., Ph.D.

Volume 98, Issue 4, Pages 922-928, October 2012


To compare obstetric and perinatal outcomes of singleton pregnancies conceived with different types of assisted reproductive technology (ART) procedures with those of naturally conceived pregnancies.

Retrospective cohort study.

The perinatal database of the Japanese Society of Obstetrics and Gynecology.

A total of 242,715 women with singleton pregnancies were examined as a base cohort. Three study groups were created according to the type of ART procedure employed, namely ovulation stimulation medications (n = 4111), intrauterine insemination (IUI) (n = 2351), and in vitro fertilization/embryo transfer (IVF-ET) (n = 4570). Controls adjusted for multiple maternal characteristics were selected randomly for each study group.


Main Outcome Measures:
Obstetric and perinatal outcomes.

Patients who conceived through the ART procedures were associated with an increased incidence of placenta previa, preterm delivery, and low birth weight infant and a decreased incidence of spontaneous cephalic delivery, regardless of the type of ART procedure.

Among singleton pregnancies, patients conceived with ART procedures were at increased risk for several adverse obstetric and perinatal outcomes, regardless of the type of ART procedure employed. These results suggest that maternal factors associated with infertility may contribute to the adverse outcomes rather than the ART procedures themselves.

  • It’s always a hard task to do a retrospective study, specially due to the high quantity of missing information in the databases.
    Did you have a high rate of missings in the study of hypertension during
    pregnancy? I wonder if that could explain the protective factor that
    IVF seems to have on PIH in your study. Another thing I would like to
    know is which confounders did you use to obtain the adjusted odds ratio
    of low birth weight and small for gestational age.
    Thank you and congratulations for your work!

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