Obstetrics Definitions 4 Flashcards
Birth of the fetus with the occiput directed posteriorly; anterior rotation of the occiput fails to occur
Persistent occipitoposterior or face to pubes
A hereditary enzyme deficiency which can cause mental retardation; a blood test is routinely taken a few days after birth to exclude this condition; incidence I in 10,000 birth
phenylketonuria
Use of light energy, (around wavelength 450 nm) to convert the bilirubin molecule in the jaundiced infant’s skin to a form which can be excreted without conjugation in the liver.
phototherapy
Eating of a substance usually considered inedible
pica
The organ which permit gas and nutrient transport between the fetus and the mother. Forms from the chorion frondosum with a maternal decidual contribution
placenta
Placental separation from the uterine decidua prior to birth of the baby.
placenta abruption
Deficiency of decidua basalis and/or deeper than normal implantation of the placenta, with chorionic villi attached to uterine muscle. In placenta increta the villi are in the muscle wall; in placenta percreta the villi are through the muscle wall (a variety of uterine rupture)
placenta accreta
Placenta with a double fold of amnion forming a ring on the fetal surface some distance in from the edge of the placenta
placenta circumvallata
A thinner, larger placenta where there is failure of atrophy of the usual proportion of the chorionic villi
placenta membranacea
exists when the placenta is inserted wholly or in part into the lower segment of the uterus
placenta praevia
the placenta lies over the internal cervical os
major praevia
: the leading edge of the placenta is in the lower uterine segment but not covering
the cervical os, minor or partial praevia exists
minor/partial praevia
Accessory lobe of the placenta may be multiple
placenta succenturiata
(a) Schultze retroplacental haematoma turns the placenta inside-out and the shiny fetal surface, with umbilical cord attached, presents. (b) Matthews-Duncan. The placenta separates edge first and slides out with the maternal surface (cotyledons) exposed.
placenta separation mechanisms
The relationship of a defined area on the presenting part (called the denominator) to the mother’s pelvis
position of the fetus
Signs that are infallible; fetal heart sounds, palpable fetal parts or movements, ultrasonography and tests for the presence of chorionic gonadotrophic hormone in the urine or blood.
positive sign of pregnancy
Small triangular space in the fetal or infant skull situated at the posterior end of the sagittal suture
posterior fontanelle
The fetal occipital bone is directed to the posterior aspect of the maternal pelvis, either to the left (LOP) or to the right (ROP). It occurs in about 15-20% of labours and is commonly associated with
prolonged and difficult labour It causes more trouble in labour than any other obstetric complication
posterior position of occiput
. (a) Primary. Blood loss in excess of 500 mL from the birth canal, during the third stage and for 24 hours afterwards, (b) Secondary. Excessive bleeding, occurring in the interval from 24 hours after delivery until the end of the puerperium (volume not specified).
postpartum haemorrhage
Baby born after more than 40 completed weeks of gestation.
post-term infant
Labour of less than 4 hours duration.
precipitate labour
Premature spontaneous rupture of the membranes before 37 weeks gestation without the onset of contractions Preterm infant. Baby born before 37 weeks gestation
preterm prelabour rupture of the membranes
That part of the fetus felt on abdominal or vaginal examination.
presenting part
The interval after menstruation, and up to ovulation during which growth of the endometrium is stimulated by oestrogen from the developing Graafian follicle.
proliferative phase of menstrual cycle
Labour of more than 24 hours’ duration.
prolonged labour
Pregnancy prolonged 14 days or more past the due date of confinement (full term); the incidence is approximately 4% (table 17.1) and has fallen since induction of labour is often performed at full term + 7 - 10 days.
prolonged pregnancy
Naturally occurring substances, in the decidua, semen and many tissues. The PGEI, PGE2 and PGF2 compounds stimulate uterine muscle activity and also cause oxytocin release from the posterior lobe of the pituitary.
prostaglandins
A phantom pregnancy, the woman thinks she is pregnant but she is not. A royal illness (Queen Mary). Seen typically in the premenopausal nullipara anxious for a child.
pseudocyesis
Bilateral injection of local analgesic in the region of the ischial spines, which renders the vagina and perineum insensitive to pain.
pudendal nerve block
developing after birth until 6 weeks postpartum. Sepsis may be defined as infection plus systemic manifestations of infection.Most common site of puerperal sepsis is the genital tract. It could also cause by mastitis, UTI, pneumonia, skin and soft-tissue infection, gastroenteritis, pharyngitis and bacterial meningitis.
puerperal sepsis
The period during which the reproductive organs return to their prepregnant condition, usually regarded as an interval of 6 weeks after delivery
puerperium
When the woman in first becomes aware of fetal movements, add 5 calendar months (22 weeks) to calculate the due date.
quickening
A common complication, of large fibromyomas in pregnancy associated with pain due to ischaemic necrosis.
red degeneration
Term used to describe any infant who develops a respiratory rate greater than 60 per minute, has difficulties in breathing as shown by retraction of the sternum and lower costal margin, and an expiratory grunt
respiratory distress
A condition which is due to lung immaturity and surfactant deficiency in preterm infants, previously it was known as hyaline membrane disease. May be treated with exogenous surfactant
respiratory distress syndrome (RDS)
When the fetal head is born it is free to undo any twisting caused by internal rotation
restitution
Placenta still in utero 1 hour after birth of the baby
retained placenta
The quality of uterine muscle, whereby permanent shortening occurs after contractions in labour. The uterine fundus thickens and pulls up the dilating cervix like a hood over the presenting part
retraction
Occurs in obstructed labour when Bandl’s ring rises to about the level of the umbilicus and becomes visible and palpable
retraction ring
The uterine fundus lies in the rectovaginal pouch of Douglas instead of anteriorly on the bladder. Occurs in 20% of women.
retroversion of the uterus
An antigen attached to red blood cells capable of causing production of antibodies when introduced into the circulation of a person lacking this factor (a Rh negative person).
rhesus factor
(a) Internal. The occiput rotates to the anterior position and rarely (1-2%) to the posterior position. (b) External. The head rotates after it is born because the shoulders (bisacromial diameter) are turning into the anteroposterior diameter of the pelvic outlet
rotation of the head
Causes pain in mid-pregnancy that may be confused with renal infection or red degeneration of a fibroid. The hypertrophied muscular ligament is in spasm and often is readily palpated lateral to the uterus in the lower abdomen. Appendicitis must be considered when the pain is unilateral and right-sided.
round ligament strain
Cold oedema of the newborn.
sclero-oedema
Voluntary muscles of the abdominal wall, and diaphragm, which by their contraction increase intra-abdominal pressure in the second stage of labour. Intrauterine pressure rises to 110 mm of mercury with the combined effect of primary uterine action (35-60 mm) and secondary powers (50 mm).
secondary powers in labour
The interval between ovulation and the succeeding menstrual period during which oestrogen and progesterone from the corpus luteum stimulate growth of the endometrium and glycogen secretion of the glands.
secretory phase of menstrual cycle
Obstruction to the passage of the shoulders through the bony pelvis; the head having been delivered, the neck fails to appear and the baby’s chin burrows into the mother’s perineum when the occiput is anterior
shoulder dystocia (impacted dystocia)
A discharge of mucus and blood at the onset of labour when the cervix dilates and the operculum (cervical mucus plug) falls out
show
That part of the fetal head in front of the anterior fontanelle, it is subdivided into the brow and the face
sinciput
Infant born with a birth weight less than the 10th centile.
small for gestational age (SGA)
fetus has an estimated fetal weight or abdominal circumference of less than the 3rd centile
severe SGA
A pathological restriction of the genetic growth potential. Growth restricted fetuses may manifest evidence of fetal compromise (abnormal Doppler studies, reduced liquor volume).
fetal-growth restriction
An infant with birth weight less than 2500g at or beyond 37 weeks gestation.
low birth-weight
infants are those weighing less than 1500g; they comprise 1 % of all births and provide 50% of perinatal deaths.
very low birth-weight
infants weigh less than 1000 g at birth and comprise 0.5% of all births
extremely low birth-weight
Overlapping of the cranial bones seen radiographically; is a sign of fetal death if moulding due to labour can be excluded. Fetal death is now confirmed with ultrasonography and/or cardiotocography.
spalding sign
Painful uterine contractions, without cervical effacement or dilatation.
spurious or false labour
(a) The first stage is that of dilatation of the cervix and is finished when the uterine cavity and vagina are no longer separated by a rim of cervix (full dilatation) (b) The second stage is from full dilatation of the cervix to delivery of the fetus (c) The third stage is completed with the delivery of the placenta and membranes (secundines)
stages of labour
The level of the presenting part, within the mother’s pelvis. The ischial spines are the reference points on vaginal examination
station
Baby delivered without signs of life from 24 weeks gestation or a birthweight ≥500g.
stillbirth
Are red or purple in colour during the pregnancy in which they first appear, later become white
striae (stretch marks)
A method of inducing labour. Less effective than amniotomy. but also carries the risk of infection.
stripping of the membranes
In late pregnancy 10% of women experience faintness when lying supine due to inferior vena caval obstruction causing reduced venous return and a fall in cardiac output,
supine hypotension syndrome
Term applied to the membranous junction between the bones of the fetal (and infant) skull; the chief sutures are between the frontal bones (frontal), parietal bones (sagittal), parietal and frontal (coronal). parietal and occipital (lambdoid)
suture
Division of the pubic symphysis, to enlarge the diameters of the bony pelvis
symphysiotomy
A fetal heart rate above 160 beats per minute and a maternal heart rate above 100 beats per minute; in each case is indicative of distress.
tachycardia
A deformed or twisted foot (clubfoot)
talipes
From 37 to 42 completed weeks’gestation (259-293 days), neither preterm 42 weeks. The due date of confinement or full term (often mistakenly referred to as ‘term’) is calculated to be 40 weeks (280 days).
term
Medical process of ending a pregnancy as to not result in the birth of a baby.
termination of pregnancy
A hereditary disorder of haemoglobin synthesis present in about 6% of women who were born in Greece and 4% of those born in Italy. It is also common in South East Asia. May cause severe pregnancy anaemia.
thalassaemia minor
Infection with Candida albicans; usual sites are the mother’s vagina and the baby’s mouth
thrush
Women with one previous caesarean delivery should be reviewed formally by a senior obstetrician early in pregnancy to discuss the management of the pregnancy and the mode of delivery. The views of the woman should be sought, including her plans for future pregnancies.
trial of labour after caesarean section (TOLAC)
A period of approximately 3 months
trimester
The cells, which line the blastodermic vesicle and surround the embryonic cell mass. Chorionic processes or villi develop with outer syncytial and inner cytotrophoblastic layers
trophoblast or chorion
A genetic abnormality, where the individual has 45 chromosomes (XO karyotype) instead of 46 and is sex chromatin negative, despite being female in appearance.
turner syndrome
Use of high frequency, short wavelength, sound wave reflections to diagnose pregnancy, assess
gestational age fetal and neonatal anatomy diagnose multiple pregnancy malpresentations and hydatidiform mole identify non-viable pregnancies, locate the placental site investigate fetal and neonatal haemodynamics, detect fetal malformations and direct intrauterine manipulation
ultrasonography
The connecting lifeline between the fetus and placenta; it contains 2 umbilical arteries and 1 umbilical vein encased in Wharton jelly
umbilical cord
a) Primary;Inefficient uterine activity. (b) Secondary; (uterine exhaustion). Occurs usually in the late first, or second stage when uterine action becomes poor or ceases. In the second stage the commonest cause is obstruction due to a tight perineum in a nullipara.
uterine inertia
Noise made by maternal blood passing through the uterine vessels.
uterine souffle
Generalized tonic contraction, of the uterus usually due to misuse of oxytocic drugs.
uterine tetany
Instrumentation to deliver the fetal head by traction on a suction cup placed on the scalp (usually the occipital region)
vacuum extraction
Dilatation of veins, of the lower half of the body. Usually occur for the first time or become worse in pregnancy
varicose veins
Fetal vessels coursing through the membranes over the internal cervical os and below
the fetal presenting part, unprotected by placental tissue or the umbilical cord. This can be secondary to a
velamentous cord insertion in a single or bilobed placenta (vasa praevia type 1), or from fetal vessels running
between lobes of a placenta with one or more accessory lobes (vasa praevia type 2)
vasa praevia
The umbilical cord inserts onto the membranes over which the vessels course to reach the fetal surface of the placenta
velamentous insertion of the cord
Produced by sebaceous glands this ‘complexion cream’ prevents waterlogging and maceration of the fetal skin by the amniotic fluid
vernix caseosa
A turning of the fetus in utero whereby the presentation is changed, usually from breech to vertex
version
. Top of the skull, the area between the anterior and posterior fontanelles and the parietal eminences
vertex
The average weight gain in pregnancy is about 12.5 kg. A weight gain of more than 0.5 kg per week in late pregnancy may precede generalized oedema
weight gain
The mucoid connective tissue supporting the umbilical cord vessels
wharton jelly
