foetus, early pregnancy problems and miscarriage Flashcards
what period of pregnancy is crucial for organogenesis?
6-12 weeks
what is a miscarriage?
Spontaneous loss of pregnancy before the foetus reaches viability.
(all pregnancy losses from the time of conception until 24 weeks of gestation)
what amount of pregnancies end in miscarriage?
1 in 5 pregnancies will end in a loss before 12 weeks
what is a biochemical pregnancy?
when you have hormones (hCG) but not signs of pregnancy
Biochemical loss - when there was evidence of pregnancy but they go away, it happens before clinical signs of pregnancy.
what are the types of miscarriage?
related to time
biochemical, early pregnancy loss and late pregnancy loss.
what are the risk factors for miscarriage?
- Gestational age: <6weeks -25%,6-12weeks-12-20%,12 weeks 1-2%
- Chromosomal abnormality: 50% of miscarriage
- Maternal and paternal age
- Previous miscarriage
- Pre-pregnancy weight
- Alcohol intake
- Smoking, Excessive Caffeine
what are the types of miscarriage?
Threatened miscarriage Inevitable miscarriage Incomplete miscarriage Complete miscarriage Septic miscarriage Anembryonic miscarriage(Blighted ovum) Missed miscarriage (Silent or delayed)
what is a threatened miscarriage ?
when the woman has a little bit of bleeding but the baby is find
could be due to a little bit of separation from the womb
what is an inevitable misscariage?
inevitable - the miscarriage has already started and you can’t stop it
what is septic miscarriage?
when there is an associated infection
what is incomplete miscarriage
incomplete miscarriage when there is products of pregnancy left in the womb.
what is a missed miscarriage (/silent or delayed)
when you have seen the heart beat but it is no longer there
what are the ultrasound criteria for diagnosis of miscarriage?
Crown-rump length of at least 7 mm and no heartbeat.
Mean gestational sac diameter of at least 25 mm and no embryo.
Absence of embryo with heartbeat at least 2 weeks after an ultrasound scan
that showed a gestational sac without a yolk sac.
Absence of embryo with heartbeat at least 11 days after an ultrasound scan
that showed a gestational sac with a yolk sac.
when can you first see the heart beat?
6 weeks
what happens if you can’t see heart by 7 weeks?
baby has probably miscarried.
what are the stages of miscarriage?
- USS shows early an embryonic or fetal death
- vaginal bleeding occurs
- open cervical OS (inevitable miscarriage)
- miscarriage (products of conception are expelled and cramps and bleeding soon subside)
what is an ectopic pregnancy?
A pregnancy located outside of the uterine cavity, usually in the fallopian tube. Incidence is 11.1/1000 pregnancies
what is the most common site for ectopic pregnancy?
the ampullary region of the fallopian tube
what are the sites that ectopic pregnancies can occur?
ypes: Tubal (Ampullary, cornual), ovarian, cervical, abdominal, cervical
what is a heterotopic pregnancy?
one in the fallopian tube and one in the womb
what are the common symptoms of ectopic pregnancy?
- abdominal or pelvic pain
- amenorrhoea or missed period
- vaginal bleeding with or without clots .
what are less common symptoms of ectopic pregnancy?
dizziness, fainting or syncope shoulder tip pain urinary symptoms passage of tissue rectal pressure or pain on defecation.
what are the signs of ectopic pregnancy?
Common signs:
pelvic tenderness
adnexal tenderness
abdominal tenderness
Other signs:
cervical motion tenderness
rebound tenderness or peritoneal signs pallor
abdominal distension
enlarged uterus
tachycardia or hypotension
shock or collapse orthostatic hypotension.
why does a pseudo sac occur in ectopic pregnancy?
because of rising oestrogen - secretions appear like a pseudo sac
you can tell if it is a proper pregnancy if it has a yolk sac inside it.
what is recurrent miscarriage ?
Loss of three or more consecutive pregnancies
It affects 1% of couples trying to conceive
1-2% of second trimester pregnancies miscarry before 24 weeks
what are risk factors for recurrent miscarriage?
- Environmental : Maternal age, previous miscarriages, advanced paternal age, obesity, alcohol ,smoking , excessive caffeine.
- Antiphospholipid antibody: 15% of women with recurrent miscarriages (inhibits trophoblast function and complement activation)
- Genetic factors : balanced translocation, chromosomal abnormalities
- Anatomical factors: Uterine malformations, Cervical weakness
- Endocrine: Uncontrolled Diabetes, Thyroid dysfunction, PCOS.
- Immune factors: Uterine natural killer cells
- Infection
- Thrombophilia
what are the investigations of recurrent miscarriage?
Referral to specialist clinic
Antiphospholipid tests
Cytogenetic analysis
Pelvic ultrasound to assess uterine anatomy Thrombophilia tests
what is gestational trophoblastic disease?
molar pregnancies
Hydatidiform mole
what are the types of hydatidiform mole?
- benign - 80%
- invasive mole - 10-15%
choriocarcinoma - malignant 2-3% of hydatidiform moles
what are complete and partial hydatidiform moles?
normal conception (2 sets of genes, 1 paternal, 1 maternal normal fetus)
complete mole (2 sets of paternal genes, no maternal genes, nofetus)
partial mole (3 sets of genes, 1 maternal, 2 paternal, no viable fetus)
risk factors for molar pregnancies?
Epidemiology Incidence in UK is 1 in 714 live births
Higher incidence in Asian women Extremes of age increases risk
Previous molar pregnancy
Diets low in protein, folic acid, and carotene
Defects in the egg, abnormalities of uterus etc
Women with Blood Group A
what is the clinical diagnosis of hydaitidiform mole?
Vaginal bleeding after amenorrhea
Hyperemesis gravidarum, hyperthyroidism Passing of grape like vesicles
what is the radiological diagnosis of molar pregnancy?
Complete Mole : Absent gestational sac & a complex echogenic intrauterine mass with cystic spaces(snow storm)
Partial Mole: May resemble a normal conception Ovaries may develop Theca lutein cysts
when does the blastocyst reach the uterus?
5th day after fertilisation
what happens in the embryo at 4 weeks?
Rapid growth occurs and the embryo’s main features begin to take form. This process is called differentiation, which produces the varied cell types (such as blood cells, kidney cells, and nerve cells)
A notochord forms in the center of the embryonic disk.
Gastrulation commences.
A neural groove (future spinal cord) forms over the notochord with a brain bulge at one end. Neuromeres appear.
Somites, the divisions of the future vertebra, form.
Primitive heart tube is forming. Vasculature begins to develop in embryonic disc.
what is the embryo susceptible to?
During this critical period (most of the first trimester), the developing embryo is also susceptible to toxic exposures, such as:
Alcohol, certain drugs, and other toxins that cause birth defects, such as fetal alcohol syndrome
Infection (such as rubella or cytomegalovirus)
Radiation from x-rays or radiation therapy
Nutritional deficiencies such as lack of folate which contributes to spina bifida
what happens at 6 weeks of embryo development
The embryo measures 4 mm (1/8 inch) in length and begins to curve into a C shape.
The heart bulges, further develops, and begins to beat in a regular rhythm. Septum primum appears.
Pharyngeal arches, grooves which will form structures of the face and neck, form.
The neural tube closes.
The ears begin to form as otic pits.
Arm buds and a tail are visible.
Lung bud, the first traits of the lung appear.
Hepatic plate, the first traits of the liver appear.[8]
Buccopharyngeal membrane ruptures. This is the future mouth.
Cystic diverticulum, which will become the gallbladder, and dorsal pancreatic bud, which will become the pancreas appear.
Urorectal septum begins to form. Thus, the rectal and urinary passageways become separated.
Anterior and posterior horns differentiate in the spinal cord.
Spleen appears.
Ureteric buds appear.
embryo at 7 weeks?
The embryo measures 8mm (0.315 inch) in length and weighs about 1 gram.
Optic vesicles and optic cups form the start of the developing eye.
Nasal pits form.
The brain divides into 5 vesicles, including the early telencephalon.
Leg buds form and hands form as flat paddles on the arms.
Rudimentary blood moves through primitive vessels connecting to the yolk sac and chorionic membranes.
The metanephros, precursor of the definitive kidney, starts to develop.
The initial stomach differentiation begins
embryo from 10th week of gestation?
From the 10th week of gestation (8th week of development), the developing organism is called a fetus.
All major structures are already formed in the fetus, but they continue to grow and develop.
Since the precursors of all the major organs are created by this time, the fetal period is described both by organ and by a list of changes by weeks of gestational age.
Because the precursors of the organs are now formed, the fetus is not as sensitive to damage from environmental exposure as the embryo was. Instead, toxic exposure often causes physiological abnormalities or minor congenital malformation.
Embryo measures 30–80mm (1.2–3.2inches) in length.
Ventral and dorsal pancreatic buds fuse during the 8th week
Intestines rotate.
Facial features continue to develop.
The eyelids are more developed.
The external features of the ear begin to take their final shape.
The head comprises nearly half of the fetus’ size.
The face is well formed.
The eyelids close and will not reopen until about the 28th week.
Tooth buds, which will form the baby teeth, appear.
The limbs are long and thin.
The fetus can make a fist with its fingers.
Genitals appear well differentiated.
Red blood cells are produced in the liver
Heartbeat can be detected by ultrasound.
The fetus reaches a length of about 15cm (6inches).
A fine hair called lanugo develops on the head.
Fetal skin is almost transparent.
More muscle tissue and bones have developed, and the bones become harder.
The fetus makes active movements.
Sucking motions are made with the mouth.
Meconium is made in the intestinal tract.
The liver and pancreas produce fluid secretions.
fetus at 18 weeks?
The fetus reaches a length of 20 cm (8 inches).
Lanugo covers the entire body.
Eyebrows and eyelashes appear.
Nails appear on fingers and toes.
The fetus is more active with increased muscle development.
“Quickening” usually occurs (the mother and others can feel the fetus moving).
The fetal heartbeat can be heard with a stethoscope.
