To evaluate the effects of inadequate antenatal care (ANC) caused by the COVID-19 pandemic on pregnant women. In this retrospective study, pregnant women were divided into two groups as those presenting during the pandemic and non-pandemic periods. The pandemic period was selected as March 11, 2020- December 10, 2020 and the pre-pandemic period as March 11, 2019- December 10, 2019 corresponding to the same period a year earlier. Pregnant women receiving ANC three times or less was defined as inadequate ANC. The pregnant women were evaluated in terms of obstetric complications, including premature rupture of membranes, premature birth, placental abruption. gestational diabetes mellitus (GDM), preeclampsia, fetal or neonatal death, and maternal death. The study included 276 patients presenting during the pandemic period and 229 patients presenting during the non-pandemic period. When the pandemic and non-pandemic periods were compared, it was determined that the rates of fetal death, preeclampsia and GDM statistically significantly increased in the former. The rate of adequate ANC was 72.5% (n=166) in the non-pandemic period and 58.3% (n=161) in the pandemic period. When pregnancy complications were compared according to ANC during the pandemic, it was observed that the rates of fetal death, preeclampsia and GDM were higher among the pregnant women with inadequate ANC. Complications due to inadequate ANC may have more significant consequences than complications caused by a possible COVID-19 infection. During the pandemic period, healthcare professionals should ensure that women receive safe and effective care during both pregnancy and childbirth.