Miscarriage and Pregnancy Loss Glossary
Using the Term "Pregnancy Loss"
Why "pregnancy loss" is the preferred term on this site.
Basic Pregnancy Terminology
Definitions for basic pregnancy-related terms as they apply to miscarriage and pregnancy loss.
Basic Labor Terminology
Definitions for basic labor and delivery-related terms as they apply to miscarriage and pregnancy loss.
Abdominal Circumference (AC)
Abdominal circumference is an important measurement in the assessing of fetal growth in a late pregnancy ultrasound. Learn more about abdominal circumference.
Alpha fetoprotein (AFP)
Alphafetoprotein is a substance produced by a developing baby during pregnancy. Abnormally high levels of alphafetoprotein measured during the triple or quad screen prenatal blood test can indicate a higher likelihood of neural tube defects and other disorders.
Definition: the clear or yellowish fluid surrounding a fetus during pregnancy.
Anencephaly is a type of neural tube defect in which the baby's brain does not develop beyond a brainstem. The defect is ultimately fatal and most babies die shortly after birth.
Aneuploidy is a condition in which a cell has extra copies or missing copies of specific chromosomes (such as a monosomy or a trisomy). Aneuploidy is often cited as a cause for miscarriage and stillbirth.
Antiphospholipid Syndrome (APS)
Antiphospholipid syndrome, or APS, is an autoimmune disorder in which the body's immune system forms antibodies against certain normal substances present in blood, causing a greater than average tendency to form blood clots and increasing odds of pregnancy loss. As many as 10-25% of women who have recurrent miscarriages have antiphospholipid syndrome.
Bereavement is the state of loss, and is frequently used interchangeably with grieving.
A bicornuate uterus is a type of congenital uterine malformation (mullerian duct abnormality) that causes the uterus to be heart-shaped. A women with a bicornuate uterus faces increased risk of preterm birth.
Biparietal Diameter (BPD)
Biparietal diameter (BPD) is a measurement that is useful in dating a pregnancy and estimating fetal weight after about 13 weeks of pregnancy. Learn the full definition of biparietal diameter.
Catharsis, from ancient Greek, is re-experiencing your emotions surrounding past events in order to release or let go of them.
Certified Nurse Midwife (CNM)
Definition of a Certified Nurse Midwife
Definition of cervical change: In labor, the cervix dilates and effaces to allow the fetus passage from the uterus through the vagina to the outside world.
Definition of contraception
Bisphenol A (BPA)
Bisphenol A (BPA)is a controversial chemical present in numerous plastics and other consumer products.Learn more about BPA.
A blighted ovum is a miscarriage in which the baby does not but the woman remains pregnant and the gestational sac continues to grow in the uterus.
Cervical insufficiency, also called incompetent cervix, is a condition where the cervix is weakened and tends to begin to dilate early in pregnancy (without contractions) before the baby is ready to be born. Women with cervical insufficiency may suffer recurrent miscarriages or premature births.
The cervix is the lower, narrow portion of the uterus that dilates and opens to allow passage of menstrual blood and during birth.
A chemical pregnancy is an early pregnancy loss in which the only evidence of the pregnancy is biochemical.
Choriocarcinoma is a malignant type of cancer that can develop in the uterus after a molar pregnancy but also after a normal pregnancy or D & C. It can also rarely occur in men.
The chorionic villi are tiny finger-like projections on the edge of the placenta that faces the wall of the uterus.
The term chromosomal abnormality, as it pertains to miscarriage and pregnancy loss, means that a developing baby has an incorrect number of chromosomes or chromosomes with missing or extra pieces.
Complete Hydatidiform Mole
A complete hydatidiform mole is the scarier of the two types of molar pregnancy; a complete molar pregnancy can result in an invasive mole or in choriocarcinoma, complications that require further monitoring of hCG levels after the miscarriage.
Congenital Uterine Malformation
A congenital uterine malformation, or müllerian duct abnormality, is an abnormal shape or difference in the structure of a woman's uterus that results from problems during her own prenatal development. Many of these malformations increase the risk of miscarriage or preterm delivery.
Crown Rump Length (CRL)
In a pregnancy ultrasound, the CRL (crown rump length) is a measurement from the top of the baby's head to the bottom of the buttocks. The CRL may be a factor in calculating gestational age, but it usually cannot be measured until about seven weeks of pregnancy.
D&C - Dilation and Curettage
A D&C is the surgical procedure doctors use to terminate a pregnancy following diagnosis of a miscarriage. A D&C involves dilation of the cervix and removal of the contents of the uterus.
D&E - Dilation and Evacuation
A D&E, or dilation and evacuation, is one means of treating a second trimester pregnancy loss. The procedure is similar to a D&C, except that it includes suction.
Decidual bleeding is the name for bleeding during pregnancy that may occur around the time that a pregnant woman would otherwise expect her menstrual period. The phenomenon is fairly rare and usually does not last longer than the first few months of pregnancy.
Diethylstilbestrol (DES) is a drug that was once prescribed to women to reduce risk of miscarriage; it has since been associated with causing birth defects. DES is no longer used but the uterine defects it caused can increase miscarriage risks in women whose mothers took the drug.
An ectopic pregnancy is a situation in which a fertilized egg implants and begins to develop outside the uterus, usually in a fallopian tube.
The term embryo is used for the developing baby up until the tenth week of pregnancy, at which point the baby is called a fetus.
Estriol is a type of estrogen that is produced during pregnancy. Abnormal levels of estriol tested in the triple or quad screen prenatal test can indicate increased risk of congenital problems in the baby.
Expectant management of miscarriage is the choice to wait for the miscarriage to occur naturally without medical or surgical intervention to expedite the process.
Factor V Leiden (FVL)
Factor V Leiden is a common genetic mutation that leads to increased risk of blood clots and is associated with pregnancy complications.
A family practitioner is a physician who has specialized in family medicine. Family practitioners may sometimes be referred to as general practitioners, and their training includes attending prenatal care and childbirth in pregnancies without high risk complications.
Femur Length (FL)
The femur length (FL) in a pregnancy ultrasound measures the length in centimeters of the femur bone in the developing baby. The femur length may be a factor in calculating the dates for a pregnancy or monitoring growth.
In a pregnancy context, fertilization refers to the sperm meeting the egg to begin creating the ball of cells that will become the developing baby.
The medical term for the earliest signs of a baby in an early pregnancy ultrasound. With a transvaginal ultrasound, the fetal pole becomes visible around 6 weeks of gestation.
Uterine fibroids are lumps of tissue growth in the uterus that are sometimes associated with miscarriage or infertility risk.
Definition of a Genetic Counselor
The gestational age of the pregnancy is technically the number of weeks since the mother's last menstrual period.
The gestational sac is where a baby develops in the uterus during pregnancy. The sac encloses the baby and amniotic fluid, and the placenta attaches the sac to the uterine lining.
Gestational Trophoblastic Disease
Gestational trophoblastic disease refers to molar pregnancies, such as partial or complete hydatiform moles, and the possible complications that can result, such as invasive moles or choriocarcinoma.
Grief is the complex emotional, physical, cognitive, and psychological experience of loss. Symptoms of grief are highly variable among cultural groups, and within individuals even in the same culture.
Gynecology is the specialty of medicine focused on healthcare for women. Physicians who practice gynecology are often also trained in obstetrics, the discipline of medicine focusing on care specifically throughout and after pregnancy.
hCG (Human Chorionic Gonadotropin)
Human chorionic gonadotropin, or hCG, is a hormone associated almost exclusively with pregnancy. Levels of hCG can be useful in determining likelihood of miscarriage in early pregnancy.
Head Circumference (HC)
The head circumference measurement on an ultrasound is the number of centimeters around the developing baby's head. The head circumference can be a factor in dating the pregnancy or estimating the size of the baby.
A heterotopic pregnancy is a multiple pregnancy with one normal implantation in the uterus and one ectopic pregnancy. Heterotopic pregnancies are rare in couples who conceive without assisted reproduction.
Homocysteine is an amino acid that occurs in the body. Elevated homocysteine is linked to a number of medical problems including miscarriage and pregnancy complications.
A hydatidiform mole is a molar pregnancy, or a type of pregnancy loss / miscarriage involving chromosomal abnormalities that develop into a mass of tissue instead of a baby. Hydatidiform moles can be partial or complete.
Hydrops fetalis is an abnormal accumulation of fluid around the developing baby. It is sometimes seen in impending miscarriages or at-risk pregnancies.
Hypercoagulable blood has a tendency to form blood clots, which can cause complications such as deep vein thrombosis or, in some cases, recurrent miscarriages.
In-Vitro Fertilization (IVF)
In-vitro fertilization, or IVF, is a procedure that involves retrieving eggs from a woman's ovaries, fertilizing them with the man's sperm, and then returning the fertilized eggs to her uterus in hopes of creating a pregnancy.
Definition of Infertility as it relates to pregnancy loss.
Infant mortality is the number of deaths of children under 1 year of age per 1000 live births in that same time period. It can be used as an indicator of overall health of a population.
Intrauterine Fetal Demise
Intrauterine fetal demise is the clinical term for a baby that has died in the womb, leading to second-trimester miscarriage or stillbirth.
An invasive mole is a condition wherein a complete hydatidiform mole invades the wall of the uterus,. Invasive moles occur after complete molar pregnancy, roughly 20% of the time, either before or after treatment and can require chemotherapy.
Labor is the process by which a fetus and placenta moves from the uterus to the outside world. This article focuses on labor as it is related to miscarriage, stillbirth, and other types of pregnancy loss.
Last Menstrual Period
Last Menstrual Period is the date used to calculate the due date of a woman's pregnancy.
Lupus Anticoagulant (LAC) Antibodies
Lupus anticoagulant antibodies are one of the types of antibodies associated with antiphospholipid syndrome; antiphospholipid syndrome is a known risk factor for recurrent miscarriages.
Definition of maternal in a reproductive biology context.
Maternal Fetal Medicine Specialist (Perinatologist)
A maternal fetal medicine specialist, or perinatologist, is a physician with special training in pregnancy complications. Perinatology specialists usually consult with OB/GYNs in complicated or high-risk pregnancies.
Medical Miscarriage (Medical Management)
Medical miscarriage refers to the use of a prescription drug to terminate a pregnancy that has been confirmed to be non-viable.
Midwife (Certified Nurse Midwife)
A certified nurse midwife (CNM) is a type of nurse practitioner trained to provide prenatal care through pregnancy and attend delivery of infants. Midwives usually handle low-risk pregnancies only.
A miscarriage is a pregnancy loss before the 20th week of gestation.
Learn more about the use of misoprostol in miscarriage treatment.
A molar pregnancy is a nonviable pregnancy in which a fertilized egg with specific chromosomal abnormalities turns into a mass of tissue in the uterus rather than developing into a baby. The pregnancy could also be a hydatiform mole in which parts of a baby develop but the pregnancy is nonviable.
Chromosomal mosaicism means that the cells throughout a person's body do not all have the same chromosomal makeup. For example, some cells may carry a trisomy condition while other cells have a normal number of chromosomes.
Mourning is the culturally prescribed set of activities people do to demonstrate loss. Mourning activities vary by culture, religious group, region, and historical period.
In most pregnancies, the placenta develops as a single round or oval shaped organ, but in some cases, it may develop two lobes (bilobed placenta) or an accessory placenta (succenturiate placenta) may form.
Natural Killer Cells
Natural killer cells (NK cells) are a normal part of the body's immune system. Some researchers have theorized that elevated NK cells may cause recurrent miscarriages, but the available data does not support this idea.
Definition of neonatal death
A neonatologist is a doctor who specializes in caring for newborn infants with special medical needs.
NICU (Neonatal Intensive Care Unit)
A definition of the specialty hospital unit and a brief description of the reasons an infant would be admitted.
OB/GYN (Obstetrics and Gynecology Specialist)
An OB/GYN is a trained physician specializing in obstetrics and gynecology. OB/GYNs typically handle health issues relating to women's reproductive health, including prenatal care and pregnancy issues.
Using the term partner on this site is meant to accomodate all readers.
Perinatal mortality is any death occurring from the time of viability in pregnancy until a week after birth.
Obstetrics is the discipline of medicine that focuses on care of women throughout the cycle of pregnancy, from preconception to childbirth and the postpartum period. Board certified obstetricians are often called OB/GYNs, as they are usually also certified as gynecologists.
Partial Hydatidiform Mole
A partial hydatidi form mole is less frequently associated with further complications than a complete molar pregnancy. A partial hydatidiform mole is a nonviable pregnancy that always results in miscarriage.
Definition of paternal in a reproductive biology context.
Pitocin is a drug commonly administered during or after miscarriage to cause contractions or reduce bleeding after delivery.
The placenta is an essential organ to maintaining a healthy pregnancy. Problems with the placenta are a leading cause of miscarriage and stillbirth.
Preeclampsia is a dangerous condition that happens in some pregnancies. Preeclampsia may cause long-term complications for both mother and baby, and can be fatal.
Pre-Implantation Genetic Diagnosis (PGD)
Pre-implantation genetic diagnosis is a procedure used in conjunction with IVF in which a technician removes a cell from a fertilized egg that has begun to develop and analyzes the chromosomes to look for specific genetic abnormalities.
Pregnancy of Unknown Location (PUL)
A pregnancy of unknown location (PUL) is a pregnancy in which the ultrasound shows no gestational sac, but it's not possible to be certain that it's an ectopic pregnancy.
Preterm delivery generally refers to the birth of a baby before 37 weeks of pregnancy. Very early preterm delivery can lead to pregnancy loss, and premature infants can be at an increased risk of neonatal death.
Products of Conception
A medical term used to name any tissues that develop from a pregnancy.
Progesterone is a hormone involved in women's menstrual cycles and in reproduction. Some researchers believe that low progesterone may cause miscarriages, but evidence is inconclusive. Low progesterone might be called luteal phase insufficiency or luteal phase defect.
Prolactin is the hormone that stimulates milk production and breast development in women. Too-high levels of prolactin may be associated with miscarriages and infertility.
Definition: A rainbow baby is a baby born after a miscarriage or other pregnancy loss.
Recurrent Miscarriage (or Recurrent Pregnancy Loss)
The term recurrent miscarriage refers to two or more consecutive pregnancy losses. Recurrent miscarriages may have a treatable underlying cause or they may happen for no apparent reason.
A reproductive endocrinologist (RE) is an OB/GYN who has completed a fellowship and subspecialty in reproductive endocrinology and infertility. RE specialists frequently handle testing for causes and subsequent treatment of recurrent miscarriages.
Sexually Transmitted Infection (STI)
Definition of Sexually Transmitted Infection as it relates to pregnancy loss.
RhoGAM is an immune globulin injection given after a birth or miscarriage to women who are Rh negative in order to prevent later pregnancy complications.
The term sonogram is a synonym for an ultrasound scan. During pregnancy a sonogram may be used to get information on the baby's growth and development or to analyze possible miscarriage symptoms.
Spontaneous abortion is a medical term doctors often use to describe a miscarriage.
Women often use the term "spotting" to refer to very light vaginal bleeding in pregnancy or between periods. Spotting can be a first symptom of impending miscarriage but can occur for other reasons as well.
A stillbirth is a pregnancy loss after 20 weeks in which the baby dies before birth.
Surgical management of a miscarriage refers to the use of a D & C to end a pregnancy that is not viable.
Teratogens are agents that disrupt the development of a baby when the mother is exposed during pregnancy. Known teratogens include toxic chemicals, radiation, viruses, and even ingested agents like alcohol.
The term "threatened miscarriage" refers to a pregnancy complicated by vaginal bleeding or severe cramping in which the outcome has not yet been determined.
The term thrombophilia means a person has an increased tendency to form internal blood clots due to a genetic or immune system abnormality.
Definition of trimester.
Definition of transvaginal ultrasound.
A translocation is a chromosomal abnormality in which a part of a chromosome has broken off and fused to another chromosome.
A trisomy is a specific type of chromosome abnormality in which an individual has three rather than two copies of a particular chromosome. Trisomies are frequent causes of miscarriage.
An ultrasound technician or technologist, sometimes called a sonographer, is an allied health professional trained to operate ultrasound equipment, taking measurements and images requested by a physician. It takes around two years to become a certified ultrasound technician.
A uterine septum is a band of tissue in the middle of a woman's uterus that results from a problem in prenatal development, causing the uterus to not form properly. Uterine septums increase the risk of miscarriage.
Vacuum aspiration is a surgical procedure used during the first trimester to end a pregnancy either as an elective termination or as a treatment for miscarriage. In lay terminology vacuum aspirations are often referred to as D&Cs even though the former does not involve a sharp curette.
A velamentous cord is an umbilical cord that is inserted in the amniotic sac with blood vessels traversing to the placenta, rather than inserted directly into the placenta. A velamentous umbilical cord can lead to serious pregnancy complications.
Viable Pregnancy (Viability)
A pregnancy is said to be "viable" when there are no signs of miscarriage or impending pregnancy loss and the pregnancy can be expected to result in the birth of a live infant. If a doctor says a pregnancy is not viable, this means that pregnancy loss is inevitable, such as in an ectopic pregnancy.
The yolk sac is the first thing that becomes visible inside the gestational sac in early pregnancy on an ultrasound. It is an early structure that helps to nourish the developing fetal pole until the circulatory system is developed and disappears as the embryo grows.