SARS-CoV-2 utilizes the angiotensin-converting enzyme 2 (ACE2) receptors located on membranes to enter host cells. Nevertheless, the ACE2 gene primarily encodes for a zinc metalloproteinase, which is a part of the renin–angiotensin system (RAS). ACE2 downregulation results in the deregulation of RAS in favor of pro-fibrosis, pro-apoptosis, oxidative stress, pro-inflammation, aldosterone production and release, and blood vessel contraction axis. ACE2 is highly expressed in the placenta. There are both axes of the RAS system in the placenta. This study aims to assess the perinatal outcomes with ACE2 receptor polymorphisms in pregnant women infected with SARS-CoV-2 during pregnancy. The case-control study was conducted to determine the association of ACE2 single-nucleotide polymorphisms in 171 COVID-19-positive pregnant subjects and 112 control subjects. The recessive mutations of rs2158082 and rs4830974 were associated with an increased risk of low birthweight and preterm birth, whereas the dominant mutation of rs2285666 (CT + TT) was associated with decreased odds of low birthweight. COVID-19 was not a significant factor contributing to the adverse perinatal outcomes in our sampling. These findings may help to clarify the controversy regarding the increased risk of adverse perinatal outcomes observed during COVID-19 as well as provide new perspectives for research on the genetic factors associated with a higher risk of adverse perinatal outcomes.