Recurrent miscarriage (abortion)

RECURRENT MISCARRIAGE

Definition:

 Recurrent miscarriage (abortion) is defined as a  sequence of three or more consecutive spontaneous miscarriages. Some however, consider two or more as a standard. It may be primary or secondary (having previous viable birth). A woman procuring three consecutive induced abortion is not a habitual aborter.

Incidence: This distressing problem is affecting approximately 1% of all women of reproductive age. The risk increases with each successive abortion reaching over 30% after three consecutive losses.

Etiology

The causes of recurrent abortion are complex and most often obscure. More than one factor may operate in a case. Factors may be recurrent or non-recurrent. There are known specific factors which are responsible for early or late abortion and they are grouped accordingly.

FIRST TRIMESTER ABORTION:

  • Genetics – In early abortion, a recurring aneuploid abnormality of the conceptus is probably responsible. It may be a chance event or related to maternal age. The most common type of 4% in couples with recurrent pregnancy failure (0.2 in normal population).
  • Endocrinal: (1) Poorly controlled diabetic patients do have an increased incidence of early pregnancy failure. (2) Presence of thyroid auto antibodies is often ossociated with an increased risk but it is likely that this finding is secondary to a generalized autoimmune abnormality rather than a specific endocrine dysfunction. Thyroid function is usually normal. (3)  Inadequate luteal phase with less production of progesterone is too often related but whether the diminished progesterone level is the cause or effect is not clear. (4) Polycystic ovarian syndrome with elevated LH and androgen is too often responsible. There may be disturbed endometrial prostaglandin secretion leading to suboptimal implantation.
  • Infection: Infection in the genital tract can be responsible for sporadic spontaneous abortion but its relation to recurrent wastage is inconclusive. The organisms implicated are – Mycoplasma, Ureaplasma, Chlamydias and bacterial veginosis. Systemic infection with  toxoplasma and brucella are also implicated.
  • Immunological cause:

Autoimmunity – The association of raised circulating lupus anticoagulant (LA) and anti-phospholid antibodies (APAs) with recurrent fetal loss is established. APAs positive women demon strate a tendency to miscarry at progressively lower gestational ages. The entity tends to be associated with recurrent miscarriage.

Placental vascular atherosis, intervillus thrombosis and decidual vasculopathy with fibrinoid necrosis are the immediate pathology for fetal loss 

  • Alloimmunity – There is failure of maternal recognition of trophoblast lymphocyte crossreactive antigen (TLX). Consequently there is lack of production of blocking antibodies by the mother. This is due to sharing of Human Leucocyte Antigen (HLA) between the partners 
  • Idiopathic: In the majority, the cause remains unknown, but the following are often related – (i) Psychological strain by raising the intrauterine pressure can cause abortion in susceptible individual. (ii) Incompatible ABO group matings as mentioned earlier.

SECOND TRIMESTER ABORTION:

            The causes of recurrent mid trimester abortions are more well defined and are mostly due to defect in the cervico-uterine environment resulting in accommodation problems of the fetus.

  • Cervical incompetence – 20%:

Causes: The retentive power of the cervix (internal os) may be impaired functionally and/or anatomically due to the following conditions: (a) Congenital – rare, (b) Acquired (iatrogenic) – common, following 9i) D + C operation, (ii) induced abortion by D + E (10%), (iii) vaginal operative delivery through an undilated cervix and (iv) ampution of the cervix or cone biopsy.

Diagnosis is based on the following criteria:

  • History – Repeated mid trimester abortions without apparent cause, starting with escape of liquor amnii followed by painless expulsion of the products of conception is very much suggestive.
  • Internal examination: (i) Interconceptional period – Bimanual examination reveals presence of unilateral or bilateral ter and / or gaping of the cervix upto the internal os.

(ii) During pregnancy – Periodic inspection of the cervix through speculum from 10th week onwards at weekly intervals is to be done. Detection of dilation of the internal os with herniation of the membranes is diagnostic.

Investigations:

Interconceptional period – The following procedures may be adopted for confirmation  of the diagnosis.

(i)   Passage No. 6 – 8 Hegar dilator beyond the internal os without any resistance and pain and absence of internal os snap on its withdrawal specially in premenstrual period indicate incompetence.

(ii)   Premenstrual hystero-cervicography shows funnel shaed shadow. The internal os is supposed to be snap on its withdrawal specially in premenstrual period indicate incompetence.

During pregnancy : Ultrasonographic findings of cervical length less than 3 cm and width f internal os more than 1.5 cm in first trimester with or without bulging of the membranes are suggestive.

  • Defective Mullerian fusion – such as double uterus, septate or bicornuate uterus. The association is about 10% cases of recurrent abortion. Abortions tend to recur beyond 12 weeks and the successive pregnancies are carried longer. Implantation on the septum leads to defective placentation. The diagnosis is confirmed either by hysterography or hysteroscopy combined with laparoscopy in non-pregnant state or during digital  exploration following abortion.

Case history: The patient had three consecutive midtrimester abortions. Hysterography reveals bicornuate uterus. Uteroculoplasty was done. Pregnancy occurred one year later, which was delivered by Caesarean section at 39 weeks.

  • Uterine synechae – may be responsible for recurrent fetal loss due to defective placentation over the adhesions.
  • Uterine fibroid – Causing accommodation problem, defective implantation or increase in uterine irritability.
  • Retroverted uterus – as mentioned previously.
  • Chronic maternal illness – such as uncontrolled diabetes with artelosclerotic changes or retinopathy, chronic nephritis, essential hypertension, systemic lupus erythematosus.
  • Infection – Syphilis, toxoplasmosis and listeriosis may be responsible in some cases
  • Idiopathic – This group is much less than first trimester recurrent abortion.

INVESTIGATIONS

A through medical, surgical and obstetric history with meticulous clinical examination should be carried out to find out the possible cause or causes as mentioned previously. Careful history taking should include – (i) The nature of previous abortion process (ii) Histology of the placenta or karyo typing of the conceptus, if available (iii) Any chronic illness.

Diagnostic tests: (1) Blood-glucose (fasting and post prandial), VDRL, Thyroid function test, ABO and Rh grouping (husband and wife), Toxoplasma antibodies IgG & IgM (2) Autoimmune screening- lupus anticoagulant and anticardiolipin antibodies. If positive – to repeat the test after 6 weeks to avoid false positive results. (3) Serum LH on D2 / D3 of the cycle. (4) Ultrasonography – to detect congenital malformation of uterus, polycystic ovaries and uterine fibroid. (5) Hysterosalpingography in the secretory phase to detect – cervical incompetence, uterine synechae and uterine malformation. (6) This is supported by hysteroscopy and or laparoscopy. (7) Karyotyping (husband and wife) (8) Endocervical swab to dectect Chlamydia, mycoplasma and bacterial vaginosis.

TREATMENT

Interconceptional period:

  • To alleviate anxiety and to improve the psychology:
  • While counseling the couple, they should be assured that even after 3 consecutive miscarriages, the chance of a successful pregnancy is high (65%).. However, the success rate depends on the underlying etiology as well as the age of the woman.
  • To correct the uterine pathology – Metroplasty for double or bicornuate uterus, removal of septum (hysteroscopically preferred) or myomectomy for submucous fibroid distorting the uterine cavity.
  • Chromosomal problems – If chromosomal abnormality is detectedin the couples or in the abortus, prompt referral for genetic counseling for future risk of abortion is undertaken. Karyotyping of the products of conception from future miscarriage is mandatory. In couples withreciprocal translocations, counseling should be either against further pregnancy or pregnancy following relevant gamet donation.
  • In cases of PCOS with elevated LH, pituitary suppression by GnRH analogues followed by ovulation induction with gonadotrophins improve the fetal salvage.
  • To treat the endocrine dysfunction or genital tract infections, if any.

During pregnancy:

  • Reassurance and tender loving care are very much helpful.
  • Ultrasound should be used at the earliest to detect a viable pregnancy. This will influence further management.
  • Rest – The patient should take adequate rest for a period of at least two weeks beyond the expected time of abortion (as inferred from the history).
  • Strenuous activities, intercourse and traveling are to be avoided.
  • In proved cases of corpus luteum insufficiency – Natural progesterone 25 mg as vaginal suppositories thrice daily is started 2 days after ovulation. If period fails to appear by 14 days, pregnancy test is done. If it is positive, the progesterone is continued upto 12 weeks of pregnancy. Initial study suggests that use of HCG improves pregnancy outcome in a woman with recurrent miscarriage.
  • Patients with antiphospholipid antibodies are treated with low dose aspirin (50 mg/day) and prednisone (40-60 mg/day) or low dose aspirin and heparin (5000 unis subcutaneously daily) upto 34 weeks.
  • In couple, with balanced translocation, the ongoing pregnancy should have the prenatal diagnosis by either chorion villus sampling or amniocentesis (see ch.11).
  • The fact remains that poor reproductive performance is too often associated with increased pregnancy complications. As such, all cases should require careful antenatal supervision.
  • Circlage operation for cervical incompetence is to be performed.
  • For alloimmunity husband’s leukocyte injections have been advocated.

Circlage operation: Two types of operation are in current use during pregnancy each claiming an equal success rate of about 80%. The operations are named after Shirodkar and McDonald.

Principle: A non-absorbable encircling suture is placed around the cervix at the level of internal os. It operates by interfering with the uterine polarity, preventing the internal os and the adjacent lower segment from being “taken up”.

Time of operation: In a proven case, the operation should be done around 14 weeks of pregnancy or at least two weeks earlier than the lowest period of previous wastage, as early as the 10th week. In doubtful cases, it can be done empirically as outlined above or to insepect the cervix through speculum and as soon as cervical dilatation or bulging of the membranes in visible, the operation is done, If facilities are available, prior to operation, continuing fetal growth can be observed using sonar.

Steps of shirodkar’s operation:

Step – 1 : The patient is put under light general anaesthesia and placed in lithotomy position. withgood exposure of the cervix by a posterior vaginal speculum. The lips of the cervix are pulled down by sponge holding forceps or Allis tissue forceps.

Step -2 : A transverse incision is given anteriorly below the base of the bladder on the vaginal wall and the bladder is pushed up to expose the level of the internal os. A vertical incision is given posteriorly on the cervicovaginal junction.

Step – 3 : The non absorbable suture material – No. 4 braided nylon or Mersilence (Dacron) is passed submucously with the help of an aneurysm needle or cervical needle so as to bring  the suture ends through th posterior incision.

Step – 4 : The ends of the suture are tied up posteriorly by a reef knot. The bulging  membranes, if present must be reduced beforehand into the uterine cavity. The anterior and posterior incisions are repaied by interrupted stitches using chromic catgut.

Mc. DONALD’S OPERATION

            The non absorbable suture material is placed as a purse sring suture as high as possible at the junction of the rugose vaginal epithelium and the smooth vaginal part of the cervix below the level of the baldder. The suture starts at the anterior wall of the cervix. Taking successive deep bites it is carried around the lateral and posterior walls back to the anterior wall again where the two ends of the suture are tied.

            The operation is simple having less blood loss, and has got a good success rate,  There is less formation of cervical scar and hence less chance of cervical dystocia during labour.

Post operative: (1) The patient should be in bed for at least 5-7 days. (2) The patient should be sedated by intramuscular diazepam 10 mg or pethidine hydrochloride 75 mg 8 hourly for 48 hours.  (3) Inj. Proluton depot 500 mg intramuscularly every week for four weeks. (5) Isoxsuprine (Duvadilan) 10 mg tablet is given thrice daily for 7 days.

Advice on discharge : (a) Usual antenatal advice (b) To avoid intercourse (c) To avoid rough journey  (d) To report if there is vaginal bleeding or abdominal pain.

Removal of stitch: The stitch should be removed at 38th week or earlier if labour pain stars or features of abortion appear. If the stitch is not cut in time, uterine rupture or cervical tear may occur. If the stitch is cut prior to the onset of labour, it is preferable to cut it in operation theatre as there is increased chance of cord prolapse especially in the cases with floating head.

Contraindications: (i) Intrauterine infection (ii) Ruptured membranes (iii)  History of vaginal bleeding  (iv) Sever uterine irritability.

Complications : (i) Slipping or cutting through the suture (ii) Chorioamnionitis (iii) Rupture of the membranes (iv) Abortion/ preterm labour.

Prognosis of recurrent abortion:

            The prognosis of recurrent abortion is not as gloomy as it was previously thought. It has been calculated that after one abortion, the risk of another abortion is 20%,  after two abortions 25% and after three abortions about 30%. Thus, no matter what treatment is used, the apparent cure rate after three abortions will range between 70-85%. Reassurance and tender loving care are very much helpful.

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