OB Terminology and Definitions

Amnion

The inner fetal membrane which forms the sac containing the fetus and amniotic fluid

Antepartum/Antepartal

Time period beginning with conception to the onset of labor

Attitude

Relationship of the fetal parts to one another

Breech Presentation

Presenting part being either the fetal buttocks or feet

Cervix

The neck or lowest part of the uterus; interfaces with vagina

Chorion

The outer fetal membrane closest to the intrauterine wall and surrounds the amnion

Conception

Occurs when sperm nucleus enters the nucleus of the oocyte/ovum, also called fertilization

Dilation

Expansion of the external os of the cervix from an opening of a few millimeters in size to ten centimeters

Dystocia

Difficult or abnormal labor due to a number of different reasons, both fetal and maternal

Effacement

Thinning and shortening of the cervix that occurs late in pregnancy or during labor

Engagement

Occurs when the greatest diameter of fetal head passes through pelvic inlet

Episiotomy

Incision of the perineum to facilitate birth and avoid laceration of the perineum

False Labor

Also called Braxton Hicks contractions; irregular contractions with little or no cervical change

Fetus

The child in utero from about the seventh to ninth week of gestation until birth

Fetal Attitude (or posture)

Relationship of the fetal parts to one another

Fetal Lie

Relationship of the long axis of the fetus and the long axis of the pregnant woman

Fetal Position

Location of the fetal presenting part and specific fetal structures in relation to maternal pelvis

Fetal Presentation

The fetal body part that enters the maternal pelvis first

Fundus

The upper portion of the uterus between the fallopian tubes

Gestation

The period of intrauterine development from conception through birth

Gestational Age

The number of complete weeks of fetal development

Gravida

A pregnant woman; in the Gravida/Para notation it is the number of times a woman has been pregnant

Intrapartum/Intrapartal

Time period beginning with onset of true labor through labor delivery of placenta

Involution

The reduction in size of the uterus following childbirth

Labor

The process by which the fetus is expelled from the maternal uterus

Lightening

Moving of the fetus and uterus downward into the pelvic cavity

Lochia

Maternal discharge of blood, mucus, and tissue from the uterus after birth

Multigravida

Woman in 2nd (also 3rd, or more) pregnancy

Multipara

Woman with 2 or more births

Nulligravida

Woman who has never been pregnant

Para

ANY birth occurring after 20 weeks; in the Gravida/Para notation it is the number of births that occurred after 20 weeks of gestation; in the TPAL notation it is the number of infants born after 20 weeks gestation

Postpartum/Postpartal

The 6-week period of time following childbirth

Preterm Labor

Labor that starts after 20 weeks but before 37 weeks

Primigravida

Woman pregnant for the 1st time

Primipara

Woman with one birth after 20 weeks

AFI

Amniotic Fluid Index

AFP

Alpha-fetoprotein

AGA

Average for gestational age

AMA

Advanced maternal age

AROM

Artificial rupture of membranes

BOW

Bag of waters

BPP

Biophysical profile

CPD

Cephalopelvic disproportion

C/S

Cesarean section (or C-section)

CST

Contraction stress test

CVS

Chorionic villus sampling

DV

Domestic violence

EAB

Elective abortion

EBL

Estimated blood loss

ECV

External cephalic version

EDB

Estimated date of birth

EDC

Estimated date of confinement

EDD

Estimated date of delivery

EFM

Electronic fetal monitoring

FAS

Fetal alcohol syndrome

FASD

Fetal alcohol spectrum disorder

fFN

Fetal Fibronectin

FHR

Fetal Heart Rate

GBS

Group B Streptococcus

GFR

Grunting, flaring, retracting

GTT

Glucose tolerance test

G/P

Gravida/Para

G/TPAL

Gravida/Term, Preterm, Abortion, Living

hCG

Human chorionic gonadotropin

IDM

Infant of a diabetic mother

IOL

Induction of labor

IUGR

Intrauterine growth restriction

IUPC

Intrauterine pressure catheter

LGA

Large for gestational age

LMP

Last menstrual period

NAS

Neonatal abstinence syndrome

NST

Nonstress test

NSVD

Normal spontaneous vaginal delivery

OP

Occiput posterior

PPD

Postpartum depression

PPROM

Preterm premature rupture of membranes

PROM

Premature rupture of membranes

QBL

Quantitative blood loss

RDS

Respiratory distress syndrome

ROM

Rupture of membranes

SAB

Spontaneous abortion (miscarriage)

SGA

Small for gestational age

SROM

Spontaneous rupture of membranes

SVE

Sterile vaginal exam

TAB

Therapeutic abortion (same as elective)

TOLAC

Trial of labor after cesarean

UC

Uterine contraction

VBAC

Vagina birth after cesarean

Station

Relationship of the presenting fetal part to an imaginary line drawn between the pelvic ischial spines.

Stillbirth

Fetus born dead after 20 weeks

Term

Normal duration of pregnancy (37-42 weeks)

Trimester

Three months, or one third, of the gestational period of pregnancy