If you or your partner is pregnant, you may have already found out that obstetricians use a confusing range of terms and abbreviations. Here’s an alphabetic sample of commonly used terms to help you decipher the code.

AFP – Alpha Feto Protein. A protein produced within the body of the fetus. When an anatomic abnormality results in leakage of this protein into the amniotic cavity, high levels get transferred to the mother, resulting in high maternal AFP levels. A blood test determines this and is given somewhere between the 15th and 19th week in most pregnancies.

BPD – biparietal diameter. A measurement made of a baby’s head diameter during ultrasound. It’s approximately the distance between the baby’s ears.

Breech – Refers to the baby’s position in the uterus being buttocks down.

CVS – Chorionic Villus Sampling. A diagnostic test to check the chromosomes of the fetus, analyzing a tiny piece of the placenta.

Diastasis – The separation of abdominal muscles that occurs when the uterus grows quite large.

EFM – Electronic Fetal Monitoring. Uses Doppler sound waves to detect the pattern of the baby’s heartbeat.

EDC – estimated date of confinement. This is the medical way of saying “due date.”

FL – femur length. The measurement made during ultrasound of the baby’s thighbone.

Fundus – The top of the uterus.

GDM – gestational diabetes mellitus. A sugar imbalance occurring during pregnancy, often corrected by dietary changes.

hCG – human Chorionic Gonadotropin. A hormone produced by the placenta that is used in traditional pregnancy tests, and also as part of the triple marker (or expanded AFP) test during the second trimester.

IUGR – Intrauterine growth retardation. A condition in which the baby is not growing as quickly as expected. This refers to physical growth only and has no implications for mental capacity.

Jaundice – A yellow coloration to a newborn’s skin, resulting from a buildup of bilirubin following delivery. (Bilirubin is a breakdown product of red blood cells.)

Kegels – Exercises to help strengthen the “pelvic floor” muscles and reduce incontinence (involuntary loss of urine).

Linea negra – A darkened line between the naval and pubic area that becomes prominent in some pregnant women.

LBW – low birth weight. Used to describe babies born weighing less than 2,500 grams (5½ pounds).

Meconium – The first bowel movement made by the baby. This can occur before delivery, resulting in green amniotic fluid.

Multip (or multiparous) – A woman who already had a baby.

Nullip (or nulliparous) – A woman who never had a full-term baby.

NICU – Neonatal Intensive Care Unit, the nursery providing intensive care for newborn babies who require monitoring and special care.

OA (occiput anterior) – When the back of baby’s head (occiput) is against the front of the mother’s pelvis. In this case, the baby is facing the mom’s back.

OP (occiput posterior) – When the back of the baby’s head is lying against the back of the pelvic bones. This is a less common position than OA at the time of delivery.

Primip (or primiparous) – A woman having her first baby.

Perineum – The skin and underlying tissue between the vagina and rectum.

Quickening – The first detection of fetal movement by the mother.

ROM – Rupture of Membranes. This abbreviation refers to the bag or waters breaking. AROM (Artificial Rupture of Membranes) is when the bag of water is broken on purpose by the health provider, often to speed up labor.

U/S – Ultrasound. A test using sound waves to create a visual picture of the fetus and structures within the uterus.

VLBW - very low birth weight. Refers to birth weight less than 1,500 grams. These babies are almost always premature.

Vernix – A white cheesy cream that coats the baby’s skin in the weeks before birth.

VBAC - vaginal birth after Caesarean. Refers to vaginal deliveries that are attempted following a previous Caesarean section delivery.