Sexually transmitted diseases (STD) may cause severe disadvantages to pregnant women and their babies. STD can lead to maternal cancer, pelvic inflammatory disease and infertility; pregnancy dangers include preterm labor, premature falling-out of membranes and uterine infections. STD can be spread to the baby in-utero and during delivery. Fetal infectivity may cause low birth weight, conjunctivitis, blindness, pneumonia, sepsis, neurologic damage, fetal demise or stillbirth. Review articles are the summary of current state of understanding on a particular research topic. They analyze or discuss research previously published by scientist and academicians rather than reporting novel research results. Review article comes in the form of systematic reviews and literature reviews and are a form of secondary literature. Systematic reviews determine an objective list of criteria, and find all previously published original research papers that meet the criteria. They then compare the results presented in these papers. Literature reviews, by contrast, provide a summary of what the authors believe are the best and most relevant prior publications. The concept of "review article" is separate from the concept of peer-reviewed literature.