Gestational age: Gestational age (or menstrual age) is a measure of the age of a pregnancy where the origin is the woman's last normal menstrual period (LMP), or the corresponding age as estimated by other methods. Such methods include adding 14 days to a known duration since fertilization (as is possible in in vitro fertilization), or by obstetric ultrasonography.Prenatal nutrition: Nutrition and weight management before and during :pregnancy has a profound effect on the development of infants. This is a rather critical time for healthy fetal development as infants rely heavily on maternal stores and nutrient for optimal growth and health outcome later in life.Anembryonic gestationNational Down Syndrome SocietyNasal fractureMaternal-fetal medicine: Maternal-fetal medicine (MFM) is the branch of obstetrics that focuses on the medical and surgical management of high-risk pregnancies. Management includes monitoring and treatment including comprehensive ultrasound, chorionic villus sampling, genetic amniocentesis, and fetal surgery or treatment.Echogenic intracardiac focus: Echogenic intracardiac focus (EIF) is a small bright spot seen in the baby’s heart on an ultrasound exam. This is thought to represent mineralization, or small deposits of calcium, in the muscle of the heart.A-scan ultrasound biometry: A-scan ultrasound biometry, commonly referred to as an A-scan, is routine type of diagnostic test used in ophthalmology. The A-scan provides data on the length of the eye, which is a major determinant in common sight disorders.Prenatal diagnosis: Prenatal diagnosis or prenatal screening (note that prenatal diagnosis and prenatal screening refer to two different types of tests) is testing for diseases or conditions in a fetus or embryo before it is born. The aim is to detect birth defects such as neural tube defects, Down syndrome, chromosome abnormalities, genetic disorders and other conditions, such as spina bifida, cleft palate, Tay Sachs disease, sickle cell anemia, thalassemia, cystic fibrosis, Muscular dystrophy, and fragile X syndrome.Volume rendering: 250px|thumb| A volume rendered cadaver head using view-aligned [[texture mapping and diffuse reflection]]Twin reversed arterial perfusionBirth weight: Birth weight is the body weight of a baby at its birth.Definitions from Georgia Department of Public Health.Placenta: The placenta (also known as afterbirth) is an organ that connects the developing fetus to the uterine wall to allow nutrient uptake, waste elimination, and gas exchange via the mother's blood supply, fight against internal infection and produce hormones to support pregnancy. The placenta provides oxygen and nutrients to growing babies and removes waste products from the baby's blood.Assay sensitivity: Assay sensitivity is a property of a clinical trial defined as the ability of a trial to distinguish an effective treatment from a less effective or ineffective intervention. Without assay sensitivity, a trial is not internally valid and is not capable of comparing the efficacy of two interventions.