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Early deceleration
| A gradual decrease
in the fetal heart rate. The time from onset of the deceleration to the lowest heart rate (nadir) during the event is greater than or equal to 30
seconds. The nadir coincides with
the peak of the uterine contraction. |
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Echogenic (hyperechogenic) bowel
Intestine that reflects more sound on an ultrasound examination than usual
making it appear very white. The finding of echogenic bowel is usually a normal
variant in the majority of cases. However, the finding of echogenic bowel has
been associated with an increased risk for chromosomal abnormality, cystic
fibrosis, viral infection (CMV and parvovirus) , unexplained fetal death, growth
restriction, and premature birth.
Echogenic focus
A distinct area that reflects more sound on an ultrasound examination than
usual making it appear very white. The term commonly refers to bright spots seen
in the ventricles of the heart. Very bright small spots may represent dense papillary muscles
or tendons within the heart. Cardiac tumors may also appear as spots within the
heart . However, tumors tend to be larger, multiple, and are not as bright as an echogenic focus.
Eclampsia
New-onset convulsions (grand mal seizure) in a woman with preeclampsia.
Preeclampsia is a condition characterized by high blood
pressure and protein in the urine that develops after the 20th week of
pregnancy. The cause of preeclampsia is unknown.
Ectopic Pregnancy
A pregnancy growing outside of the uterus.
Edema
Swelling caused by the accumulation of fluid.
Edwards' syndrome (trisomy 18)
A disorder characterized by severe mental retardation and multiple
abnormalities, such as cleft lip and palate, small jaw (micrognathia), low set
ears, club feet,
clenched fists, intrauterine growth restriction, single umbilical artery, elevated amniotic fluid ( polyhydramnios),
and kidney abnormalities. More than 90% of fetuses have a heart defect.
The condition is not compatible with life, and only 5% to 10 % of infants
survive the first year
after delivery.
Edwards' syndrome occurs in about one out of 7500 live births and is caused
by extra material from chromosome 18. In most cases (80%) there are three
copies of chromosome 18 instead of two. In some cases extra material from a
piece of chromosome 18 becomes attached to another chromosome (translocation). Mosaicism (where some of the child's
cells have three copies of chromosome 18 and some cells have the normal two
copies of chromosome 18)
is a less common cause. Recurrence risk is 1% or less for
cases caused by three copies of chromosome 18. The risk of having a child with
trisomy 18 also increases as a woman gets older. If a parent is a balanced carrier
of a translocation, the risk for recurrence is much higher.
Effacement
Thinning or shortening of the cervix.
Embryo
A fertilized egg from initial cell division until the eighth week of
development.
Encephalocele
A defect affecting the skull resulting in the herniation of the meninges and
portions of the brain through a bony midline defect in the skull
Engagement
Passage of the widest diameter of the presenting
of the part of the fetus (usually the head) to a level below
the first sacral vertebra and the symphysis
pubis (the joint between the pubic bones at the front of the
pelvis).
Epidural
A method of pain relief in which anesthesia is injected into
the space around the spinal cord (epidural space) to numb the lower body.
Episiotomy
An incision made between the vagina and rectum to widen the vaginal opening for delivery.
Erythema infectiosum (Fifth disease)
Erythema infectiosum also known as Fifth disease is a common childhood
illness caused by a virus called parvovirus B19. The virus appears to be
transmitted by person-to-person contact through saliva, sputum, or nasal mucus. About
50% of all adults have been infected sometime during childhood or adolescence.
The incubation period for the infection is 4 to 14 days. Persons infected
with the virus may experience fever, malaise, joint pain (particularly of the
peripheral joints), and profuse nasal discharge. There may be a lacelike rash on
face, trunk , and extremities (See
image)
.The infection is
sometimes mistaken for rubella. Persons are no longer infectious after the appearance of the rash.
Women who become infected with parvovirus for the first time during their
pregnancy may pass the virus to their unborn child. Parvovirus can cause severe anemia in the fetus which
may lead to congestive heart failure. The heart itself may become enlarged. In
addition parvovirus infection has uncommonly been associated with enlarged
ventricles in the fetal brain and calcium deposits in the spleen. The overall fetal loss rate
related to
maternal infection ranges from 2% to 10%.
Women suspected of having a new parvovirus infection during pregnancy are
usually followed with serial ultrasounds for 8 to 12 weeks after infection to
detect the development of anemia or fetal hydrops.
The thinned out blood of the anemic fetus may be detected by measuring the flow
of blood through middle cerebral artery of the brain. Fetal hydrops
is a condition where fluid collects in the abdomen, around the lungs, and skin
due to congestive heart failure.
Leave from the workplace
is controversial and is not routinely recommended
Estimated Fetal Weight , EFW
A calculated approximation of the weight of a human conceptus from 70 days'
gestational age and
older. Where weight is defined as the force that must be applied to an object in order to support it.
EFW can be done by mothers (if they are parous), by clinicians using Leopold
manoeuvres or by ultrasound.
EFW may be estimated from
Leopolds
mothrer or sonogram get acog and emed citaitons as well.
An ultrasound estimated fetal weight is calculated from models (mathematical equations) using measurements of the fetus obtained during an ultrasound examination, and is sometimes used to predict birth
weight.
For birth weights in the range of 1000 to 4500 grams models using 3 or 4 fetal biometric indices appear to be more accurate than models that incorporated only 1 or 2 indices.
The accuracy of weight estimation decreased at the extremes of BWs, leading to overestimation in low-BW categories as opposed to underestimation when
the BW exceeded 4000 g. The precision of most models was lowest in the low-BW groups.
By incorporating the standard ±15% error margin that can be
expected with fetal weight estimates made by ultrasonography,
Melamed N, et al. Sonographic fetal weight estimation: which model should be used? J Ultrasound Med. 2009 May;28(5):617-29.PMID: 19389901
Chauhan SP, Hendrix NW, Magann EF, Morrison JC, Kenney SP, Devoe LD.
Limitations of clinical and sonographic estimates of birth weight: experience
with 1034 parturients. Obstet Gynecol 1998;91:72–77 (Level II-2)
Chauhan SP, Sullivan CA, Lutton TD, Magann EF, Morrison JC. Parous patients'
estimate of birth weight in postterm pregnancy. J Perinatol 1995;15:192–194
(Level II-2)
Ultrasonography is helpful in detecting fetal growth disturbances. Four
standard fetal measurements generally are obtained as part of any complete
obstetric ultrasound examination after the first trimester: 1) fetal abdominal
circumference, 2) head circumference, 3) biparietal diameter, and 4) femur
length (41). Fetal morphologic parameters can be converted to fetal weight
estimates using published formulas and tables (42). Contemporary ultrasound
equipment calculates and displays an estimate of fetal weight on the basis of
these formulas. Although all of the published formulas for estimating fetal
weight show a good correlation with birth weight, the variability of the
estimate generally is plus or minus 16 to 20% (2 standard deviations) (41).
In general, ultrasound-established dates should take preference over
menstrual dates when the discrepancy is greater than 7 days in the first
trimester and greater than 10 days in the second trimester. Ultrasonography may
be considered to confirm menstrual dates if there is a gestational age agreement
within 1 week by crown rump measurements obtained in the first trimester or
within 10 days by an average of multiple fetal biometric measurements obtained
in the second trimester (up to 20 weeks of gestation). Reassigning gestational
age in the third trimester should be done with caution because the accuracy of
ultrasonography is within 3 4 weeks
Guidelines for assignment of gestational age when a discrepancy exists between
menstrual and ultrasound-established dates vary in different ultrasound units
Ultrasonography in Pregnancy. ACOG Practice Bulletin No. 101. American
College of Obstetricians and Gynecologists. Obstet Gynecol 2009;113: 451–61.
41. Hadlock FP, Deter RL, Harrist RB, Park SK. Estimating fetal age:
computer-assisted analysis of multiple fetal growth parameters. Radiology
1984;152:497 501. (Level II-3)
Estrogen
A group of steroid compounds that includes estradiol, estriol, and estrone. Estrogens are produced by the
granulosa cells of developing egg follicles in the ovary, the corpus luteum, and
the placenta. They are also produced in small amounts by peripheral tissues, the adrenal
glands, and in men by the testes.
Estrogens promote the development of secondary female sexual characteristics,
and influence the metabolism of bone and the production of many substances produced by
the liver.
Estradiol (E2) is the primary hormone produced during a woman's reproductive
years. It reaches high levels just before ovulation occurs during the menstrual
cycle, and is produced in large quantities by the placenta from fetal and
maternal adrenal steroids.
Normal Values
External cephalic version
To manually turn the fetus
from a breech (sitting position) presentation to a cephalic presentation (head
down nearest to the cervix) by applying external pressure on the mother's
abdomen.
Extremely lo birth weight (ELBW)
A birth weight of less than 1000 grams ( 2 pounds 3 ounces)
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