We aimed to review the evidence on the impact of lockdowns on adverse birth and pregnancy outcomes (ABPOs) and related inequalities in high-income countries (HICs). Databases were searched from Jan 1, 2019-June 22, 2023, for original observational studies based in HICs which compared the rates of ABPOs, before and during lockdowns. We ran random effects meta-analyses and subgroup analyses per region, lockdown period, ethnicity group, and deprivation level, we also adjusted for underlying temporal trends. 132 studies were meta-analysed. Preterm birth (PTB) decreased in the first lockdown (RR = 0·96[95%CI:0·93 − 0·99]), when only considering studies that adjusted for long-term trends, this reduction in PTB remained (0·97[0·95 − 0·99]). The reduction was larger in Europe (0·94[0·92 − 0·96]) and Australia (0·94[0·90 − 0·99]), and only observed in white ethnicity groups (0·94[0·89 − 0·98]), and in those living in low deprivation (0·95[0·91 − 0·98]). More women screened positive for possible depression antenatally during lockdown (1·37[1·06 − 1·78]). Lockdowns affected advantaged and disadvantaged subgroups in an unequal manner.