Corresponding author
Helena Ban Frangež, M.D., Ph.D.
Department of Human Reproduction, Division of Obstetrics and Gynecology, University Medical Centre Ljubljana
Šlajmarjeva 3, 1000 Ljubljana, Slovenia
GSM: 386 41 336 441
helena.ban.frangez@gmail.com
Running title : Preterm delivery after reproductive surgery
Abstract
Objective:  To evaluate an association between the mode of conception and preterm delivery in women after reproductive surgery, and to explore an effect of reproductive surgery on preterm delivery.
Design : Prospective cohort study and historical case-control study.
Setting : Division of Obstetrics and Gynecology, Ljubljana, Slovenia.
Population or sample : A cohort of 761 infertile women after reproductive surgery.
Methods : In infertile women, we evaluated the association between the mode of conception and preterm delivery using logistic regression adjusted for relevant co-variables. In a case-control study we evaluated the effect of reproductive surgery on preterm delivery using propensity score method. We calculated the adjusted odds ratios with a 95% confidence interval with a two-way test.
Main Outcome Measure : Preterm delivery.
Results : Among 761 infertile women, 428 (56.2%) conceived spontaneously, and 333 (43.8%) conceived after IVF/ICSI. The incidence of twin pregnancies was significantly lower after spontaneous conception (2.6% vs. 14.1%; p <0.000 ). Adjusted logistic regression analysis in singleton pregnancies disclosed no significant association between the mode of conception and preterm delivery. Compared with fertile women, the incidences of preterm deliveries < 37, and < 32 gestational weeks were higher in infertile women (11.2% vs. 14.2%, and 1.7% vs. 2.6%, respectively). However, the differences did not reach a statistical significance (p=0.076  and p=0.218 , respectively).
Conclusion:  In selected infertile women after reproductive surgery, a high rate of spontaneous conception, a low rate of multiple pregnancies, and no treatment-related adverse effect on preterm delivery should be the reasons to encourage spontaneous conception after reproductive surgery.
Funding: The authors received no funding.
Keywords : reproductive surgery, preterm delivery, spontaneous conception, IVF/ICSI, infertile women