Pregnancy following infertility: a concern?

This study is to assess whether a waiting time to pregnancy (WTP) >1 year elevates the risk of adverse pregnancy outcomes in essentially healthy women with a single normal fetus at a gestational age of >20 weeks. Comparisons were made between those who conceived spontaneously with those who conceived after treatment for infertility. A retrospective analysis of 1,020 pregnancies occurring after a delay (WTP) of >1 year was undertaken over a 6-year period. Of these pregnancies, 24 resulted from advanced reproductive techniques and were excluded, as were four first trimester abortions, leaving 992 women. Of these 992, study group A (treated) consisted of 553 (56%) women, of whom 312 (56%) were primigravidae (A1). The pregnancy outcomes were compared with those of the remaining 439 (46%) women who conceived spontaneously, group B (control, untreated). Of these women, 234 (53%) were primigravidae (B1). Results suggested that primigravidae in the study group showed an increased risk of pre-term births and this risk was statistically significant between the gestations of 34 and 37 weeks. This risk remained elevated after adjustment for covariates. Pregnancies of women in group A1 were appreciably shorter than those of primigravidae who got pregnant without treatment (36.1 +/- 0.8 weeks vs 39.2 +/- 2.1 weeks); had lower birth weights (2684 +/- 481 g vs 3481 +/- 703 g) and were more likely to be admitted to the neonatal intensive care unit. Primigravidae among the treated group showed a statistically significant risk of caesarean births.