A decrease in the fetal heart rate below the baseline heart rate lasting at
least 15 seconds.
Detailed Obstetric Notation
In an obstetrical history the gravida (G) and para (P) status of a woman is
often written in abbreviated form. Where:
Gravida is the number of pregnancies a
woman has had. A multiple gestation counts as a single pregnancy.
Para is the number of completed pregnancies beyond 20 weeks gestation
(whether viable or nonviable). A multiple gestation counts as a single birth.
a woman who has been pregnant 3 times (where one pregnancy was a set of
triplets) has one term delivery, one preterm delivery (of her triplets), and one
termination at 16 weeks would be described as:
G 3,P 2
Expanded obstetric notation gives more detail:
G, T-P-A-L =
Gravida (Total number of pregnancies), Term births -Preterm births -
Abortions - Living children
Term births means delivery at 37 or greater weeks'
Preterm birth means delivery at 20 to 36 6/7
Abortion is delivery before 20 weeks' gestation.
Living children means children who lived beyond
In expanded form the woman with triplets from the previous example would be described as G
3, P 1- 1- 1- 4 indicating
3 pregnancies, 1 term delivery, 1 preterm delivery, 1 miscarriage or termination of
pregnancy, and 4 living children.
Two separate amniotic sacs (bags of water)
The muscle used for breathing . It divides the chest from the abdomen.
Diaphragmatic hernia (congenital
diaphragmatic hernia -CDH)
An abnormal opening in the diaphragm (most often on
the left side) caused by
failure to completely form the diaphragm. The defect allows
the abdominal organs to move into the chest cavity which may prevent normal
development of the lungs. The condition is associated with a 30 to
60% death rate due to underdeveloped lungs and associated abnormalities such as
heart defects, malformed or absent kidneys, and hydrocephalus. The presence of
the liver in the chest generally increases the likelihood of a
Diaphragmatic hernia occurs in one per 2,000 to 3,000 births. Chromosome abnormalities are seen in up to 15% of fetuses with diaphragmatic hernia. The most common
chromosome abnormalities are trisomy 18,
and trisomy 21. The defect has also been reported in association with multiple
syndromes including Fryn and Cornelia de Lange syndromes.
Congenital diaphragmatic hernia may be diagnosed prenatally on ultrasound.
The usual finding is a heart displaced away from the side of the hernia and the
presence of the stomach in the chest at the level of the heart.
Two separate placentas.
Dilation and curettage (D and C)
A surgical procedure in which the cervix is gradually opened
with instruments called dilators and the surface of the endometrium
(lining of the uterus) is scraped away with a curette, a
Dizygotic twins (fraternal twins)
A twin pregnancy most commonly
occurs when two separate eggs are fertilized by separate sperm to form two
zygotes. Each zygote implants in the uterus individually and develops its
own membranes and placenta. The two zygotes continue to develop as two
separate embryos. These twins are referred to as
dizygotic (commonly known as fraternal) twins. Fraternal twins
account for about 70 % of naturally occurring twins in the United States .
Down syndrome (trisomy 21)
A disorder characterized by mental retardation, flat facial profile with
protruding tongue, poor muscle tone, excess skin on neck, slanting
eye openings (slanted palpebral fissures),
abnormal pelvis, and short stature. In addition there may be heart defects (AV
canal defect) , gastrointestinal malformations, problems with vision and hearing,
and increased susceptibility to leukemia and
infections. The syndrome is named
after John Langdon Down, the first physician to identify the syndrome.
Down syndrome occurs in one out of 800 live births and is caused by extra material from
chromosome 21. In most cases (95%) there are three copies of chromosome 21
instead of two. In 90% of these cases the extra chromosome is inherited from the
mother. The recurrence risk for this type of Down syndrome is 1% overall and
increases the mother's age increases. Extra
material from chromosome 21 may also be inherited as a translocation where the
extra 21 chromosome is attached on to another chromosome (often chromosome 14). This
form of Down
syndrome has a much higher recurrence rate ranging from 5 to 100% depending on
on the sex of the carrier parent and
the type of chromosome rearrangement. Uncommonly a child may be born with mosaic
Down syndrome where some of the child's cells have three copies of chromosome 21 and some cells have the normal two
copies of chromosome 21.
Findings on ultrasound examination that strongly suggest the diagnosis of
Down syndrome are an atrioventricular (AV) canal defect in the heart or
duodenal atresia (double bubble sign). An increased nuchal translucency or
nuchal fold (the space in the back of a developing fetus's neck) may also suggest
Down syndrome. However, none of the above findings is exclusive to Down syndrome
and, ultimately, Down syndrome is diagnosed by analyzing
cells from the fetus.
Due date (estimated due date-EDD)
The date that spontaneous onset of labor is expected to occur.
Slow or difficult labor caused by inadequate uterine contractions,
abnormalities in the maternal pelvis, a large fetus or a combination of these
A method using ultrasound to detect and measure blood flow.
The ultrasound machine emits sound waves into
the body then measures the frequency of the sound waves returning from moving
blood cells to determine the speed (velocity) of blood flow. As cells approach the ultrasound transducer reflected sound waves are compressed
resulting in a higher frequency sound. As cells travel away from the transducer the
reflected waves are elongated
resulting in a lower frequency sound. This change in
frequency (pitch of the sound) is due to the motion of the reflecting
cells and is called The
Doppler Effect or Doppler shift.
Blood velocities can be calculated from the change in frequency of
the reflected ultrasound:
Where v is the blood velocity, c is the sound velocity in tissue, f0
is the transmitted frequency, fD is the Doppler shift of reflected ultrasound and α is the angle between the ultrasound beam and the direction of motion.