Is a woman's chronological age or 'ovarian age' more important in determining perinatal outcome after assisted reproductive treatment?

Ovarian reserve (OR) decreases as women get older but there is considerable variation in the rate at which this occurs. Older women are at increased risk of complications during pregnancy. The aim of the study was to determine whether poor OR influences perinatal outcomes independent of age. All fresh IVF/ICSI cycles in which a single embryo was transferred between 1 January 2010 and 31 December 2016 were reviewed. An anti-Müllerian hormone (AMH) concentration of ≤5.4 pmol/l was considered poor and 5.41-24.99 pmol/l normal. Data were collected regarding cycle outcome, congenital anomalies, gestational age at delivery and birth weight. A total of 1520 women were included, of whom 1197 had normal OR and the remaining 323 had poor OR. Once pregnant, after adjusting for maternal age, women with poor OR (n = 109) were no more likely to experience a biochemical pregnancy or miscarriage (41.3% versus 41.6%, p = 0.809) than women with normal OR (n = 596). There were no significant differences in rates of congenital anomalies (1.8% versus 1.2%, p = 0.636), birth weight (3272 ± 630.7 g versus 3376.4 ± 576.3 g, p = 0.216) or gestational age at delivery (38.9 ± 2.3 weeks versus 39.1 ± 2.1 weeks, p = 0.517) between women with normal or poor OR. OR does not appear to affect pregnancy loss rates, incidence of congenital anomalies, birth weight, or gestational age at delivery after adjusting for maternal age.