Spontaneous abortion is spontaneous miscarriage in early (up to 12 weeks) and late terms (at 13—22 weeks). According to different authors the frequency of spontaneous abortions makes 8—20 % of the general number of pregnancies.
genital endometriosis, chronic endometritis, operative interventions on the uterus and appendages;
therapeutic and spontaneous abortions, pretcrm delivery in anamnesis;
peculiarities of the course and pathology of the present pregnancy (severe gestoses, multiple pregnancy, hydramnion, anomalies of placenta attachment and development, premature detachment of the normally located placenta, etc.);
pathologies of the father's organism;
unfavorable socio-economic factors (ecological, age of the mother, living conditions, occupational hazards, pernicious habits, stressful situations);
Treatment If left alone most missed miscarriages will be expelled spontaneously, but during the waiting period there is a slight risk of coagulation defect and this should be investigated before embarking on evacuation of the uterus in cases of fetal death of more than four weeks. Surgical. If the uterus is not larger than the size of an eight to ten week pregnancy it may be emptied by curettage. This operation requires experience and as bleeding is free until the uterus is emptied, transfusion facilities must be available. Medical. Mifepristone, a progesterone receptor blocker may be used to 'prime' the uterus for miscarriage and be followed by the use of gemeprost or misoprostol and medical management of this condition is highly effective in producing complete miscarriage.
Causes 1. Delay in evacuation of the uterus. Either the patient delays seeking advice, or the surgical evacuation has been incomplete. Infection occurs from vaginal organisms after 48 hours. 2. Trauma, either perforation or cervical tear. Healing is delayed and infection is more likely to be a peritonitis or cellulitis. Criminal abortions are, of course, particularly liable to sepsis.
Infecting Organisms These are usually the vaginal or bowel commensals. 1. Group B haemolytic streptococcus. 2. Anaerobic streptococcus. 3. Coliform bacillus. 4. Clostridium welchii. 5. Bacteroides necrophorus. Any of these organisms but particularly the last two may be the cause of septic shock.
Preterm delivery is delivery with spontaneous beginning, progressing birth activity and delivering a fetus weighing 500 g and more at the term of pregnancy from 22 full (the 154th day from the 1st day of the last menstruation) to 37 full weeks.
In connection with the peculiarities of obstetric management of delivery and nursing of the children, who were born in different terms of gestation, the following periods should be singled out:
22-27 weeks — too early preterm delivery;
28-33 weeks — early preterm delivery;
34-37 weeks — preterm delivery.
CAUSES Certain conditions are associated with an increased risk of premature labour: (a) Social factors: Low socio-economic groups. Low maternal age. Low maternal weight. Smoking. (b) Overdistension of the uterus: Multiple pregnancy Polyhydramnios. (c) Uterine anomaly: Congenital. Cervical incompetence.
(d) Fetal anomaly (e) Infection: Maternal pyrexial illness. Amnionitis (premature rupture of the membranes) (f) Antepartum haemorrhage (g) Trauma: Injury. Surgery during pregnancy. Many cases are unexplained and the mechanisms involved in stimulating uterine action are not clear.
TREATMENT The decision to attempt to stop pre-term labour will depend on the period of gestation, the estimated fetal weight and the neonatal paediatric facilities available. Improvements in paediatric care have reduced the need for efforts to postpone delivery. Key points in the management of preterm labour 1. Need for tocolysis 2. Need for time to administer corticosteroids to accelerate fetal lung maturity 3. Need for time to transfer to Tertiary centre)
Fetal respiratory distress-syndrome! prevention is carried out from 24 till 34 weeks of pregnancy:
under the threat of preterm delivery i.m. introduction o f dexa-methasone — 6 mg every 12 h (24 mg per course) or betamethasone — 12 mg every 24 h (24 mg per course);
in case of preterm delivery beginning i.m. introduction of dexa-mcthasone — 6 mg every 6 h (24 mg per course) or betamethasone — 1.2 mg every 12 h (24 mg per course).
Tocolytic therapy is carried out till 34 weeks of pregnancy at cervical dilation less than 3 cm or at treating the threat of preterm delivery with the purpose of conducting corticosteroid therapy and if it is necessary to transfer the pregnant woman to the neonatal centre, no more than 24-48 h
For tocolytic therapy there may be used oxytocin antagonists, p-mimetics, calcium channel-blocking agents, and magnesium sulfate.
Contraindications to tocolysis at preterm delivery:
any contraindications to pregnancy prolongation;
gestational hypertension with proteinuria and other medical indications;
a mature fetus;
fetal death or fetal malformations incompatible with life;
contraindications to individual tocolytic agents.
At 35-36 weeks of pregnancy, if there are no signs of infection, antibacterial therapy is begun in 18 h of waterless interval. If there is no risk of spontaneous birth activity, internal obstetric examination is conducted in 24 h.