(1) Background and Aim: The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is linked to increasing cases of coronavirus disease 2019 (COVID-19) around the world. COVID-19 infections have an important impact on pregnancy, preterm birth (PTB) and delivery. Although several complications have been reported in infected pregnant women, the effect of infection on PTB is controversial. The purpose of this study was to summarize the existing literature on the effects and complications of COVID-19 on the health of pregnant women and preterm babies and its impact on the incidence of PTB. We also discuss the effect of current COVID-19 vaccines during pregnancy. (2) Methods: We carried out a systematic search of MEDLINE, Embase, and PubMed for studies on preterm births associated with COVID-19. (3) Results and Conclusions: We discovered contradictory results regarding the prevalence of PTB during the pandemic compared to earlier years. While most studies indicated an increase in PTBs with COVID-19, some indicated a decline in the preterm delivery rate during this time. During pregnancy, COVID-19 infection can increase the incidence of cesarean section, stillbirth, ICU admission, preeclampsia/eclampsia, and mortality rates. In the treatment of pregnant women with severe COVID-19, methylprednisolone was favored over prednisolone, and a brief course of dexamethasone is advised for pregnant women with anticipated PTB to accelerate the development of the fetal lung. Generally, vaccination for COVID-19 in pregnant and lactating women stimulates anti-SARS-CoV2 immune responses, and it does not result in any noteworthy negative reactions or outcomes for the mother or baby.

Spent coffee grounds (SCGs) are common waste products that can be used as low-cost adsorbents to remove contaminants from water. SCGs come in a range of particle sizes based on how they were ground to brew coffee. However, few studies have investigated how SCG particle size influences the adsorption rate and capacities of metal ions. In this study, SCGs were washed under alkaline conditions, creating exhausted coffee grounds (ECGs). ECGs were sieved into four particle size ranges (106–300, 300–500, 500–710, and 710–1000 μm). Monocomponent batch adsorption experiments were conducted with each size fraction using 0.3 mM Pb2+, Cu2+, Zn2+, and Ni2+ at pH 5.5 to examine the effect of particle size on the adsorption rates and capacities. The initial adsorption rates for all the four metal ions were 8–12 times higher for the smallest ECGs compared to the largest ECGs. Slower initial adsorption rates with increasing particle size were due to intraparticle diffusion of metal ions into the porous structure of ECGs. However, the equilibrium adsorption capacities for each metal ion and the surface acidic group concentrations were similar across the range of particle sizes studied, suggesting that grinding ECGs does not substantially change the number of adsorption sites. The equilibrium adsorption capacities for Cu2+ and Pb2+ were 0.18 and 0.17 mmol g–1, respectively. Zn2+ and Ni2+ had lower adsorption capacities of 0.12 and 0.10 mmol g–1, respectively. The time needed to reach equilibrium ranged from less than 2 h for Zn2+ and Ni2+ adsorption onto the smallest ECGs to several hours for Pb2+ or Cu2+ adsorption onto the largest ECGs. Future adsorption studies should consider the effect of ECG particle size on reported adsorption capacities, particularly for shorter experiments that have not yet reached equilibrium.