Data analysis plan - Are there sex differences in pregnancy outcome in pregnancies in women of Advanced Maternal Age?

Women of advanced maternal age (defined as pregnancy in women ≥40 years of age) have increased risk of pregnancy complications including: hypertensive disorders of pregnancy, fetal growth restriction, miscarriage, placental abruption, preterm birth and stillbirth compared to women of optimal childbearing age (20-30 years of age). Some of these associations are thought to be mediated by placental dysfunction. To some extent, a phenotype of placental dysfunction is replicated in animal models. Some animal studies have suggested a sexually-dimorphic effect. To date, this has been explored in three human studies that have found some evidence of different effects depending on the sex of the fetus. This data analysis plan describes a secondary analysis of the dataset from the Manchester Advanced Maternal Age Study to determine whether pregnancy outcome in advanced maternal age is influenced by fetal sex.