Comparison of outcomes in uncomplicated term and post-term pregnancy following spontaneous labor

This study was designed to compare outcomes of spontaneous labor in uncompl icated term and post-term pregnancy. It comprised of a case matched study o f 285 women with uncomplicated singleton past-term pregnancy (290-301 days of gestation) and 855 women with uncomplicated singleton term pregnancy (25 9-287 days of gestation). Term controls were matched to post-term cases on a 3:1 basis. The main outcome measures were cesarian section. Apgar scores and admission to the Neonatal intensive care unit (NICU). Cesarian section was significantly more common in women with post-term pregnancy (Relative R isk = 1.90, 95 % CI = 1.29-2.85). The increase was equally distributed betw een cesarian sections performed for failure to progress in labor (RR = 1.74 , 95 % CI = 1.02-3.04) and fetal distress (RR = 2.00, 95 % CI = 1.14-3.61). There were no differences in low Apgar scores, but admission to the NICU w as more common in the post-term group (RR = 2.69, 95 % CI = 1.39-5.54). The re was no difference in significant neonatal pathology in either group. Unc omplicated post-term pregnancy is associated with increased rates of obstet ric and neonatal interventions in terms of cesarian section and NICU admiss ions. This effect does not appear to be a result of underlying pathology as sociated with post-term pregnancy. We suggest that a lower threshold for cl inical intervention in pregnancies perceived to be,,at-risk" may be a signi ficant contributing factor.