PREGNANCY
INTERRUPTING
N. Bahnij
Pregnancy interrupting – spontaneous
preterm interrupting of pregnancy:
• To 12 weeks of pregnancy – early
spontaneous abortion
• 13-22 weeks – late spontaneous
abortion
• 22-36 weeks – preterm labor
Causes of Preterm Birth
Maternal infection
•
chronic tonsillitis
•
urinary tract infection
•
TORCH – infection
•
viral infection
•
chronic inflammatory diseases of the female sexual organs (vaginatis, bacterial vaginosis)
Amnionic Fluid Infection
•
Chorioamnionic infection
Maternal endocrine disorders:
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ovarian hormonal insufficiency - patients with the late menarche, irregular menstrual cycle, genital
infantilism, infertility;
•
adrenal impairment – hyperandrogeny
•
thyroid gland impairment - hypothoroidism
•
Organic cervical dilation (cervical incomoetence), abnormal uterine development
Medical and Obstetrical Complications
•
placental abruption, placental previa
•
pregnancy induced hypertension
•
multiple pregnancy
•
polyhydramnios
Lifestyle Factors
•
cigarette smoking,
•
poor nutrition, and poor weight gain during pregnancy,
•
use of drugs such as cocaine or alcohol have been reported to play important roles in the incidence
and outcome of low-birth weight infants;
•
low maternal age
•
poverty
•
short stature
•
occupational factors
•
psychological stress in the mother.
Classification of spontaneous abortion:
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Threatened abortion
Initial abortion
Inevitable abortion
Incomplete abortion
Complete abortion
DIAGNOSIS AND TREATMENT OF
DIFFERENT TYPES OF ABORTIONS
Threatened abortion
Signs – lover abdominal pain.
In bimanual examination – cervix is
closed, enlargement of the uterus
corresponds with gestational period
Management – conservative.
Initial abortion
Signs – lover abdominal pain, bloody
vaginal discharge.
In bimanual examination – cervix is
closed, enlargement of the uterus
corresponds with gestational period
Management – conservative.
Inevitable abortion
Signs – cramp abdominal pain thanks
to
uterine
contractions,
bloody
vaginal
discharge
till
profuse
hemorrhage.
In bimanual examination – cervix is
dilated, products of conception are
presented
on
cervical
channel,
enlargement of the uterus doesn’t
correspond with gestational period –
smaller
Management –surgical – uterine
Complete abortion – all products
of conception are expelled out of
uterus
Signs - lover abdominal pain, bloody
vaginal discharge.
In bimanual examination – cervix is
dilated or closed, enlargement of the
uterus doesn’t correspond with
gestational period – smaller.
Management
curettage
–surgical
–
uterine
Incomplete abortion – retention of
some conceptus inside the uterus
Signs – lover abdominal pain, bloody
vaginal discharge.
In bimanual examination – cervix is
dilated, enlargement of the uterus
doesn’t correspond with gestational
period – smaller, some products of
conception should be expelled out.
Management –surgical – uterine
curettage
Conservative treatment in the case of
threatened and initial abortion in early
terms
• Bed rest
• Sedative drugs – Valeriannae, Persen,
Novopaside.
• Spasmolitics – No-Spani, Papaverini
hydrochloride
• Analgetics – Analgin, Baralgin
• Progesterone – Utrogestan – 100 mg twice a day,
Duphastone – 10 mg 2-3 times a day,
Progesterone 10-25 mg in a day
• Chorionic Gonadotropin Hormone
• Vitamines – vit. E 200 mg per os, folic acid – 0,4
mg in a day
Conservative treatment in the case of
threatened and initial abortion in late
terms (after 16 weeks)
• Bed rest
• Sedative drugs – Valeriannae, Persen,
Novopaside.
• Spasmolitics – No-Spani, Papaverini
hydrochloride
• Tokolotic agents: Magnesii sulfatis 40 ml 25 % in
400 ml isotonic solution, b2- adrenomimetics (2
ml ginipral in 500 ml isotonic solution).
• Progesterone – Utrogestan – 100 mg twice a day,
Duphastone – 10 mg 2-3 times a day.
Cervical incompetence
Accounts for about 15 to 20 percent of all pregnancy
losses during the second trimester.
Premature effacement (shortening of the vaginal portion
of the cervix and thinning of the walls) and dilation of
the cervix is not caused by structural weakness in the
cervix itself.
The weakness can result from a number of conditions,
most due to prior injury to the cervix or resulting from
an inherited physical condition of the cervix.
The cervix dilates without contractions or pain,
sometimes opening completely. The dilation results in
the amniotic membranes bulging through the opening
and eventually rupturing, often before the baby can
survive outside of the uterus. This irritates the uterus
and brings on pregnancy interrupting.
Symptoms of Cervical Incompetence
• Women with incompetent cervix
typically present with "silent" cervical
dilation (i.e., with minimal uterine
contractions) between 16 and 22
weeks of gestation. They present
with significant cervical dilation (1
cm or more) and minimal symptoms.
Diagnosis of Cervical Incompetence
Diagnosis is made by:
• medical history,
• physical exam,
• and ultrasound study.
Ultrasound findings
• Funneling of the cervix with the changes
in forms T, Y, V, U (correlation between the
length of the cervix and the changes in
the cervical internal os).
• Cervix length < 25 mm
• Internal cervical os more than 10 mm
• Protrusion of the membranes.
• Presence of fetal parts in the cervix or
vagina.
Funneling of the cervix with the changes
in forms T, Y, V, U
Treatment of Cervical Incompetence
• Surgical procedure called cerclage (stitching the
cervix closed). One or more stitches are placed
around or through the cervix to keep it tightly closed.
• This is usually performed after 12 till 16 weeks of
pregnancy, the time after which a woman is least
likely to miscarry for other reasons - but it is not done
if there is rupture of the membranes or infection.
• This procedure is carried out under general
anaesthetic.
• After surgery, the mother is carefully monitored to
check for infection and contractions, which are
sometimes brought on by the procedure. After
hospital discharge, the patient may remain on bedrest
in order to remove any pressure on the cervix and
increase the chance of retaining the pregnancy until
the baby is viable. The cerclage is usually removed
just before childbirth so that the patient can give birth
vaginally.
A Shirodkar suture using Merselene tape at
the level of the internal os is the treatment
available.
McDonald suture with #4 mersilk at the
level of the internal os
Preterm labor - is the term used to
define infants who are born between
22 and 37 weeks of gestation
with the weight 500 – 2500 gram
and length 25 - 48 cm
Clinical classification of preterm labor
•Threatened preterm labor
•Initial preterm labor
•Inevitable preterm labor
Signs and Symptoms of Preterm Labor
Threatened preterm labor is characterized by:
• symptoms of pelvic pressure, low back pain;
• increase uterine tone;
• absence of cervical effacement and dilation in vaginal
examination.
Initial preterm labor is characterized by:
• irregular crampy – like painful uterine contractions;
• presence of cervical effacement and dilation of the cervix
till 3-4 cm in vaginal examination;
• amniotic fluid gush is present very often.
Inevitable preterm labor is characterized by:
• regular uterine contractions;
• cervical dilation more than 3-4 cm.
Peculiarities of Preterm labor duration:
• Preterm Ruptured Membranes
• Known risk factors for preterm rupture of the membranes
include:
1. preceding preterm labor;
2. occult amnionic fluid infection;
3. multiple fetuses;
4. abruptio placentae.
• Uterine contractions abnormalities: uterine inertia, uterine
hyperactivity, discoordination.
• Precipitatous preterm labor as a result of cervical
incompetence.
• Vaginal bleeding as a result of placental abruption or
placenta previa is most common complication in labor.
• Fetal hypoxia is more common in labor
• Infectious complications are very common in labor
(chorionamnionitis) and postpartum period (endometritis,
phlebitis).
Diagnosis of preterm labor includes:
• To learn the cause of preterm labor and its
elimination.
• To estimate gestational age of pregnancy
and probable fetal weight, its lie,
presentation, visus.
• To diagnose uterine activity (presence or
absence regular uterine contractions).
• To perform vaginal examination for
learning cervical effacement and dilation,
preterm ruptured membranes and to put
correct diagnose of the preterm labor
stage.
Management of preterm labor
1. Expectant Management - nonintervention
or expectant management, in which
nothing is done and spontaneous labor is
simply awaited
2. Active Management - intervention that
may include corticosteroids, given with or
without tocolytic agents to arrest preterm
labor in order that the corticosteroids have
sufficient time to induce fetal maturation.
Indications for expectant management:
• threatened and initial preterm labor;
• intact membranes;
• gestational age of pregnancy till 36 weeks of
gestation;
• satisfactory maternal and fetal conditions;
• cervical dilation till 2-4 cm;
• absence of infection, regular uterine contractions,
serious obstetric and extragenital pathology.
• 28-34 weeks of pregnancy with preterm ruptured
membranes, absence of regular uterine
contractions and infection.
• 28-34 weeks of gestation, intact membranes, 100
% cervical effacement and cervical dilation till 34 cm.
Expectant Management of Preterm labor in the
case of Ruptured amniotic membranes:
1. One sterile speculum examination is performed to identify fluid coming
from the cervix or pooled in the vagina. Demonstration of visible fluid or a
positive Nitrazine test is indicative of ruptured membranes. Attempts are
made to visualize the extent of cervical effacement and dilatation, but a
digital examination is not performed. A cervicovaginal specimen is taken
and culture sent for Neisseria gonorrhoeae.
2. Ultrasound examination is performed to help confirm gestational age, and
assess amniotic fluid volume.
3. If the gestational age is 34 completed weeks or less and there are no
other maternal or fetal indications for delivery, the woman is observed
closely in Labor and Delivery, with continuous fetal heart rate monitoring
4. If there is no evidence of fetal jeopardy, or if labor does not begin, the
woman is transferred to the High Risk Pregnancy Unit for close
observation for signs of labor, infection, or fetal jeopardy.
5. General blood analysis – twice a day determination of leucocytes number,
urine, vaginal smear, bacteriological examination once a 5 days.
6. To 34 weeks of pregnancy for 24-48 hours Inhibiting preterm labor drugs
are prescribed - b-adrenergic inhibitors: 2 ml ginipral is dissolved in 500
ml isotonic solution with the rate 10 drops per minute.
7. Accelerated Maturation of Pulmonary Function - Dexamethasone, 6 mg, is
given intramuscularly every 12 hours for 4 doses for enhancement of fetal
maturation.
8. Antimicrobial Therapy in the case of infection.
Indications for active management:
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•
•
•
•
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preterm ruptured membranes;
regular uterine contractions;
presence of infection;
fetal jeopardy, hypoxia;
severe maternal diseases;
birth defects of the fetus;
obstetric complications of pregnancy (severe
pregnancy induced hypertension,
polyhydramnios).
Vaginal delivery is indicated in cephalic
presentations, cesarean section is performed in
the case of breech presentation and transverse
lie.
Expectant Management of Preterm labor in the
case of Intact amniotic membranes:
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1) Bed Rest
2) Calcium Channel-blocking Drugs
Smooth muscle activity, including myometrium, is directly related to free calcium within the
cytoplasm, and a reduction in calcium concentration inhibits contraction. – Nifedipine, izoptine – 10
mg sublingualis every 15 minutes during 1 hour, after 20 mg three times a day.
3) Beta-adrenergic Receptor Agonists
There are two classes of b-adrenergic receptors: b1-receptors, dominant in the heart and
intestines; and b2-receptors, dominant in the myometrium, blood vessels, and bronchioles. A
number of compounds generally similar in structure to epinephrine have been evaluated in the
search for one that ideally would provide optimal stimulation of myometrial b2-receptors and thus
inhibit uterine contractions while simultaneously causing few adverse effects from stimulation of
receptors elsewhere.
1. Ritodrine – 1 g is dissolved in 250-400 ml isotonic solution and is prescribed invtravenously
slowly during 4-12 hours.
2. Bricanil (Terbutaline) 0.5 mg is dissolved in 250-400 ml isotonic solution. Toxicity—especially
maternal pulmonary edema and glucose intolerance—have been evident with its use (Angel and
associates, 1988).
3. Partusistene (Fenoterol, Berotek) - 0.5 mg is dissolved in 250-400 ml isotonic solution and
prescribed slowly i/v.
4. 2 ml (10 mkg) ginipral is dissolved in 500 ml isotonic solution with the rate 10 drops per minute.
4 ) Magnesium Sulfate – is not prescribed nowadays
5) Prostaglandin Inhibitors
Antiprostaglandin agents may act by inhibiting the synthesis of prostaglandins or by blocking the
action of prostaglandins on target organs. Several drugs are known to block this system, including
aspirin and other salicylates, indomethacin, naproxen, and sulindac.
Unfortunately, prostaglandin synthase inhibitors may adversely affect the fetus, and this has
prevented widespread use of these agents for tocolysis. Complications include closure of the ductus
arteriosus, necrotizing enterocolitis, and intracranial hemorrhage (Norton and co-workers, 1993).
6) Atosiban - a nonapeptide oxytocin analog. Atosiban has been shown to be a competitive
oxytocin-vasopressin antagonist capable of inhibiting oxytocin-induced uterine contractions.
7 ) Nitric Oxide Donor Drugs
Nitric oxide is a potent endogenous smooth-muscle relaxant in the vasculature, the gut, and the
uterus. Nitroglycerin is an example of a nitric oxide donor drug.
Accelerated Maturation of Pulmonary Function
Glucocorticoid Therapy – is recommended till 34 weeks for
gestation
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The mechanism by which betamethasone or other
corticosteroids are currently thought to reduce the
frequency of respiratory distress involves induction of
proteins that regulate biochemical systems within type II
cells in the fetal lung that produce surfactant (Ballard and
Ballard, 1995). The reported physiological effects of
glucocorticoids on the developing lungs include increased
alveolar surfactant, compliance, and maximal lung
volume.
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betamethasone (12 mg intramuscularly in two doses 24
hours apart) to prevent respiratory distress in the
subsequently delivered preterm infant.
•
dexamethasone, 6 mg intramuscularly every 12 hours 24 mg all dose between 22 and 34 weeks.
•
Repeated dose of hormones is not indicated.
Intrapartum Management
In general, the more immature the fetus, the
greater the risks from labor and delivery.
• Labor. Whether labor is induced or spontaneous,
abnormalities of fetal heart rate and uterine
contractions should be sought, preferably by
continuous electronic monitoring.
• Delivery.
Novadays, for relaxation of vaginal outlet, a liberal
episiotomy and Pudendal anesthesia by 0.25 %
Novocaine are not performed.
Perineal protective maneuvers don’t apply.