Second trimester miscarriage Zeena helmi Definition is defined

Second trimester miscarriage Zeena helmi

• Definition • is defined as the loss of a pregnancy prior to viability, taken legally in the UK as a gestation date of 23 weeks 6 days. Beyond this, fetal demise is classified as stillbirth. second-trimester mis- carriage occurs after 12 weeks’ gestation and accounting for 1– 4% of all miscarriages

causes 1. Cervix: cervical injury from surgery, cone biopsy and large loop excision of the transformation zone 2. Infection: may occur with or without ruptured mem- branes. May be local to the genital tract or systemic. 3. Thrombophilias. 4. Uterine abnormalities: submucous fibroids and con- genital distortion of the cavity (uterine septae) may be implicated. 5. Chromosomal abnormalities: these too may not become apparent until the second trimester.

• History-taking • • LMP: remember to confirm length of cycle, regularity, and use of contraception around time of conception, any of which can alter the presumed timing of ovulation (assumed as 15 days after LMP for the purpose of calcu- lating gestation) and hence result in over- or under- estimation of gestational age. • • Symptoms: pain and/or bleeding. • • Past obstetric and gynaecological history may provide evidence of risk factors for other nonpregnancy-related causes of bleeding or indicate risk factors for ectopic preg- nancy, such as sexually transmitted infection or pelvic inflammatory disease. It is important to ascertain the last smear date and any history of cervical abnormality/ colposcopic treatment. • • Past medical history: poorly controlled diabetes melli- tus is known to be associated with miscarriage and other chronic illnesses may also be implicated, although these tend to be associated with reduced fertility (capacity to conceive) rather than fecundity (capacity to maintain a pregnancy). • • Medication: prescribed, non-prescribed and recrea- tional

Examination • • General examination • A general examination to assess the immediate well-being of the patient is mandatory. Young women can mask blood loss and significant decompensation is a late sign; there- fore attention should be given to the subtle sign of blood loss in addition to pulse and blood pressure, respiratory rate, pallor, reduced consciousness, and capillary return. Peritoneal distension may also result in bradycardia.

Abdominal palpation • • Determine the fundal height: the uterus generally becomes palpable above the pelvic brim at 12 weeks’ gestation, although this will be affected by multiple preg- nancy and the presence of uterine fibroids. • • Examine for evidence of other pelvic masses, which may explain the presence of pain (e. g. ovarian torsion, degenerating fibroids). • Look for evidence of intra-abdominal bleeding or gen- eralized tender distension of the abdomen. • • Confirm location of pain.

Vaginal examination • Vaginal examination will reveal whether the cervix is open or if products of conception are identifiable at the cervical os. If so, the relevant tissue should be removed and sent for histopathological diagnosis, as on rare occa- sions a decidual cast (in the presence of an ectopic preg- nancy) can mimic products of conception. Products of conception cannot be confirmed on macroscopic inspec- tion unless fetal parts are seen. • Speculum examination of the vagina is also a good opportunity to inspect the cervix and vagina to exclude local causes of blood loss in addition to the quantity of loss at presentation as patient description can be misleading.

Differential diagnosis • Hydatidiform mole is a relatively rare but important com- plication of pregnancy that should be considered in all cases of miscarriage and, where possible, tissue sent for histological confirmation of products of conception.

Diagnostic tools • Ultrasound • It has a pivotal role in diagnosis of miscarriage. The ultrasound landmarks visible on transvaginal scan are as follows. • Week 5: visible gestation sac. • Week 6: visible yolk sac. • Week 6: visible embryo. • Week 7: visible amnion.

Serum human chorionic gonadotrophin • There is little evidence to support the role of beta human chorionic gonadotrophin (β-h. CG) in determining viabil- ity after the visualization of an intrauterine gestation sac and yolk sac, as considerable variation exists in the normal increase in β-h. CG and occasionally falls are iden- tified in the presence of subsequently viable pregnancy. Furthermore, the effect of twin pregnancy on βh. CG rise is uncertain.

Progesterone • The main role of progesterone lies in the assistance it provides in determining the likely outcome of pregnancy of unknown location rather than in diagnosing miscar- riage, although a progesterone level of less than 20 nmol/L suggests a non-viable pregnancy, a level above 60 nmol/L a live pregnancy (without determining its location) while values between 20 and 60 nmol/L are equivocable. Progesterone levels are also not valid where patients are taking exogenous progesterone as is often the case with assisted conception/recurrent miscarriage.

Management • Management options fall into three groups: medical, sur- gical or expectant. Factors to be taken into account when discussing these options with patients include the following. • • Type of miscarriage: • • Gestation at which miscarriage is diagnosed: care needs to be taken where miscarriage is diagnosed at later gestations (11 weeks and above where there is a missed miscarriage). These patients are at risk of heavier bleed- ing compared with earlier gestations and should be warned of such and possibly encouraged to consider sur- gical evacuation as the first line of treatment. If their pref- erence is for medical evacuation, then this is more appropriately carried out in an inpatient setting. • • Facilities available at individual units: • • Medical history: cardiac disease and sickle cell anaemia for example. The risks are increased in the presence of haemorrhage and so generally among these patients sur- gical evacuation, being associated with less blood loss, is the most appropriate choice. • • Patient choice. • • Cost.

Expectant management • Up to 85% of miscarriages will resolve spontaneously within 3 weeks of the diagnosis. • Patient satisfaction with expectant management depends on appropriate patient selection (earlier gesta- tion, singleton pregnancy, social circumstances) and counselling. Patients should be made aware of what to anticipate (pain and bleeding), be given advice regarding analgesia and what to do with the tissue passed. The advice should be backed up with written information and contact details in case of concern or complications.

Surgical management • Surgical management involves evacuation of the uterus by dilatation and suction curettage (‘evacuation of retained products of conception’ is the term in general usage in the UK. ) The procedure can be performed under general or local anaesthesia depending on local experi- ence. Cervical dilatation can be assisted by cervical priming with a prostaglandin (e. g. misoprostol) a minimum of 1 hour prior to the procedure and is strongly recommended when the woman has not had a previous vaginal delivery. This is believed to reduce the pres- sure required to dilate the cervix and hence risk of failure of the procedure, retained products and uterine perfora- tion.

• Curettage is usually safe but it is important to counsel women about the associated risks. These include the risk of general anaesthesia (if relevant), the risk of infection or retained products (3– 5%) and potential bleeding in association with this and the 0. 5% risk of uterine perforation which could lead to other organ damage and the need to progress to laparoscopy or laparotomy in those circumstances. Patients should be reassured that in the presence of a uterine perforation and the absence of additional complications, the implications for future fertility are negligible. Asherman’s syndrome, where intrauterine synechiae develop and interfere with conception, used to be said to arise from over-vigorous curettage

Medical management • Medical management of miscarriage involves using uter- otonic therapy, alone or in conjunction with antihormone therapy, to achieve evacuation of the uterine cavity. • Available uterotonic agents include gemeprost and misoprostol, both of which are prostaglandin (PG)E 1 ana- logues. Gemeprost is licensed for use in management of uterine evacuation. It requires refrigeration and is more expensive that misoprostol. Misoprostol is not licensed for gynaecological use, can be stored at room temperature and is significantly less costly. It can also be given orally as well as per vagina or rectum. Side effects include nausea, vomiting and diarrhoea, which can be problem- atic. There is no evidence to support the use of other uterotonics such as ergometrine, oxytocin or other prosta- glandins in this situation. PGE 1 analogues can be used in conjunction with antihormone therapy: mifepristone, an antiprogesterone, can be used to sensitize the uterus to the effects of uterotonics and may improve complete evacuation rates. The effect of mifepristone is maximal 36– 48 hours after treatment.

• Overall, the success rate of medical management (72– 93%) is similar to that of expectant management (75– 85%) but medical management has the advantage that patients can control the course of events by timing medi- cation to allow the miscarriage to take place. However, success rates are dependent on how much time has elapsed following treatment: the longer the wait, the higher the success rate. Compared with surgical man- agement, there is significantly more associated blood loss but no increased requirement for blood transfusion. Reassuringly, rates of infection between the three options are similar

Rhesus status • The recommended dose of anti-D immunoglobulin for miscarriage is 250 units before 20 weeks’ gestation and 500 units after 20 weeks. It is further recommended that a Kleihauer test be performed to assess the quantity of feto-maternal haemorrhage after 20 weeks.

cervical incompetence • or Cervical insufficiency (CI), occurs in 1 in 50 to 1 in 2, 000 gestations. • Risk factors • include prior cervical laceration, history of cervical conization, multiple terminations with mechanical cervical dilation, intrauterine diethylstilbestrol exposure, and congenital cervical anomaly. • One reasonable definition is recurrent painless cervical dilation in the absence of infection, placental abruption, uterine contractions, or uterine anomaly. Because CI is a diagnosis of exclusion, alternate diagnoses must be rigorously sought.

• Pelvic rest, pessary placement, and cervical cerclage have been suggested to prevent repeated pregnancy loss from CI, but the evidence for their effectiveness is mixed. • Mc. Donald or Shirodkar cerclages are placed vaginally, usually at 12 to 14 weeks’ gestation; selection of technique depends on the available cervical length and surgeon experience/preference. Rescue cerclage for CI/bulging membranes is associated with >50% risk of complications.

• Abdominal cerclage is placed at laparoscopy in rare instances for women who have minimal to no residual cervical length (often due to large cone biopsies or trachelectomy). Subsequent cesarean section is necessary. • Cerclage is removed when the patient begins to labor, when membranes rupture, if there is evidence of uterine infection, or if the patient reaches 36 weeks’ gestation.