Missed abortion definition
It is a type of abortion where the fetus is dead and retained inside the uterus for a variable period before the age of viability (before 20 weeks of gestation). If the fetus dies and retains inside uterus after the age of viability, it is called intrauterine death. If this process occurs before 12 weeks there is repeated hemorrhage in between chorion and decidua. This disrupts the villi from their attachment. The bleeding is small and do not rupture decidua capsularis. The clotted blood with the contained ovum is known as a blood mole. By this time ovum is dead and become absorbed. Gradually the fluid portion of blood gets absorbed and the wall becomes fleshy. Hence it is termed as a fleshy or careneous mole. On the other hand, if the abortion occurs after 12 weeks of pregnancy the fetus becomes mummified or macerated. The amniotic fluid gets absorbed and the placenta becomes pale, thin and may become adherent.
Missed abortion symptoms
- Absence of menstruation with other sign of pregnancy and then
- Features of threatened abortion like slight bleeding per vagina and slight lower abdominal pain
- And then brownish discharge per vagina
- Subsidence of pregnancy symptoms
- Retrogression of breast changes
- Cessation of uterine growth or fundal height is less than the period of gestation
- Cervical OS is closed
- Fetal heart sound absent
Missed abortion investigation
- Complete blood count
- Blood grouping Rh typing
- Blood coagulation profile
- Ultra sonogram of whole abdomen
- Trans vaginal ultra sonogram
- Doppler ultra sonogram
- Urine analysis
- Immunological test for pregnancy
- Serum beta hCG
- Other routine tests
Missed abortion ultrasound
Ultrasound plays a major role in maternal reassurance. It also has a great diagnostic value. Fetal cardiac activity is not seen to be active. Fetal heart sound is not audible by even a Doppler ultra sonogram which was previously audible. An empty sac in real time ultra sonogram reveals missed abortion. Experts suggest that the diagnosis of an empty gestation sac can only be made when the mean gestation sac diameter is greater than 20 mm, and that the crown rump length must be 6 mm or greater before one can say for certain that fetal heart activity is absent. If measurements are below these thresholds, expert suggestion is to repeat trans vaginal ultrasound examination after at least a week. Ultrasound features such as a sac that is much smaller than expected from a certain last menstrual period, a sac that is low in the uterus or the presence of fetal bradycardia are strongly suggestive but not diagnostic of impending miscarriage. In addition, the possibility of incorrect dates should always be remembered by the alert clinician. In missed abortion, there will be no visible movement of the fetus.
Missed abortion diagnosis confirmation
For diagnosis of missed abortion is done by correlation of symptoms, clinical examination, ultra sonogram and immunological tests. Suggestive signs, negative immunological tests and absent fetal heart sound and fetal motion and gestational sac by ultra sonogram confirms diagnosis. Final confirmation comes after the expulsion of product of conception.
Complications of Missed abortion
- Psychological upset
- Infection by gas forming organism
- Blood coagulation disorder
- Uterine inertia
- Retained placenta
- Postpartum hemorrhage
Missed abortion treatment
- Uterus less than 12 weeks:
Many women expel the product of conception within 2 weeks. To wait for spontaneous expulsion under the guidance of a doctor in hospital is termed as expectant management.
Prostaglandin E1 800 microgram vaginally in the posterior fornix is given and repeated after 24 hours if needed. Expulsion of product occurs within 2 days.
Suction evacuation or dilatation and evacuation:
These procedures are done when medical management fails. Or it can be the definitive procedure. The decision depends on the condition of the patient and doctors foresight.
- Uterus more than 12 weeks
In missed abortion beyond 12 weeks, there is no place of expectant management. Here our only goal is to expel the product of conception. The following methods are effective for missed abortion beyond 12 weeks.
Prostaglandin E1 analogue 200 microgram should be given per vaginally four hourly. This is done for maximum of five times of such dose.
10-20 units of oxytocin in 500 milliliters of normal saline at 30 drops per minute is started. If fails, escalating dose of oxytocin to the maximum of 200 mIU/min, may be used with monitoring.
Dilatation and evacuation:
We usually do dilatation and evacuation when the cervix becomes soft. We can achieve this by use of prostaglandin E1. Otherwise, mechanical dilators like laminaria tent may be used to dilate cervical canal. After dilatation of cervix evacuation of uterine cavity done very slowly. Many patients need surgical evacuation following medical treatment. Following medical treatment ultra sonogram should be done to document the product in uterus.