Bleeding in early pregnancy

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10 Bleeding in early pregnancy

Chapter Contents

Miscarriage

Definition
Types of miscarriage
Pathophysiology
Assessment
Investigations
Management
Complications
Follow-up

Therapeutic abortion

Definition
Legal aspects of pregnancy termination
Assessment
Methods of termination
Complications

Recurrent miscarriage

Definition
Prevalence
Aetiology
Assessment
Investigations
Management

Ectopic pregnancy

Definition
Incidence
Aetiology
Assessment
Management

Gestational trophoblastic disease

Definitions
Assessment
Management
Follow-up
Prognosis

Summary

Vaginal bleeding in the first trimester is a common event, occurring in up to 30% of all pregnancies, and about one-half of these will eventually miscarry by 12 weeks’ gestation. More than 90% of spontaneous miscarriage occurs in the first trimester.

Causes of bleeding in the first trimester include spontaneous abortion, physiological bleeding of a normal pregnancy, ectopic pregnancy, trophoblastic disease and non-obstetrical causes such as cervical lesions, e.g. polyps, ectropion or carcinoma.

Miscarriage

Definition

Miscarriage (abortion) is the involuntary loss or termination of pregnancy prior to 24 weeks’ gestation. Other definitions include the loss of pregnancy before viability. The World Health Organization definition is ‘expulsion or extraction of an embryo or fetus weighing 500 g or less from its mother’. However, this weight criterion corresponds to a gestational age of 20–22 weeks, the irreducible age for fetal viability. An empty sac (formerly known as blighted ovum or anembryonic pregnancy) occurs when an embryo has failed to develop although there is an identifiable gestational sac and placental tissue. This is, in fact, an early form of missed miscarriage.

Types of miscarriage (Fig. 10.1)

• Threatened – uterine bleeding without dilatation of cervix or passage of products of conception (POC). The fetus is still viable and the uterus is the expected size for dates. Only one-quarter of these will go on to miscarry.

• Inevitable – heavy bleeding with cervical dilatation, but without passage of POC. The fetus may still be alive, but miscarriage will occur.

• Incomplete – bleeding with cervical dilatation and passage of some, but not all, POC.

• Complete – bleeding which diminishes with complete passage of POC. Pain and bleeding ease, uterus returns to normal size and cervix is closed.

• Missed – fetal death, bleeding or pain; the fetus or embryo has been dead for some weeks, but no tissue has been passed. This is often not recognized until bleeding occurs, the patient complains that she feels ‘less pregnant than before’ and an ultrasound has been performed confirming fetal demise.

• Septic – any of the above that becomes infected, resulting in endometritis and often parametritis and peritonitis.

image

Figure 10.1 Stages of miscarriage.

Pathophysiology

Up to 50% of spontaneous miscarriages are the result of a major genetic abnormality, e.g. trisomy. The remainder have been linked to other factors such as uterine abnormalities (such as fibroids or müllerian duct abnormalities), cervical incompetence (usually mid-trimester loss), maternal systemic disease, progesterone deficiency in the luteal phase of the cycle and immunological factors.

Once the woman has a positive pregnancy test and the pregnancy fails, there is usually a cessation of the symptoms of pregnancy and the serum human chorionic gonadotrophin beta-subunit (βhCG) levels plateau or fall. Eventually, she will begin to bleed and after hours or weeks of bleeding in varying amounts she will experience lower abdominal cramping or back pain. At this point the eventual outcome is recognized even if the pregnancy failed weeks previously. The final event in this sequence is the passage of POC as the body attempts to evacuate the contents of the uterus, and this is often associated with severe pain, bleeding and often symptoms and signs of shock if products remain in the cervix.

This sequence of events is often mimicked by ectopic pregnancy and, therefore, this must always be excluded. Both entities have positive pregnancy tests, variable symptoms of pregnancy, vaginal bleeding and pelvic pain. However, a ruptured ectopic pregnancy will produce signs of shock and signs of a haemoperitoneum, such as rebound tenderness, rigid abdomen or shoulder-tip pain (caused by diaphragmatic irritation).

Assessment

When a patient presents with first-trimester bleeding, begin with an accurate history including careful questioning on the sequence of events, symptoms, menstrual history, method of contraception, previous obstetrical, gynaecological, surgical and medical history. Attempting to establish estimated/expected gestation of the pregnancy is imperative.

General examination including vital signs and cardiovascular status must be performed. An abdominal examination is important, particularly if one suspects an ectopic pregnancy, assessing for signs of a haemoperitoneum. A speculum examination will eliminate any local cause of vaginal bleeding and will reveal any cervical dilatation, and at this stage POC can be removed with a sponge holder if seen in the cervix. A bimanual examination may be necessary if the speculum examination is normal and this will allow assessment of uterine size, cervical dilatation, cervical excitation – pain on movement of the cervix (an indicator of a possible ectopic or pelvic infection) – and the presence of an adnexal mass.

Investigations

• Full blood count, blood group and consider serum βhCG assay

• Ultrasound scan of pelvis.

Management

• Conservative

• Uterine curettage (evacuation of retained POC – ERPC) if incomplete or non-viable pregnancy

• Anti-D immunoglobulin if patient is Rhesus D-negative.

The management of bleeding in early pregnancy will depend on clinical, ultrasound and biochemical factors.

Clinical

If the clinical picture suggests complete, incomplete or threatened miscarriage, an ultrasound scan should be arranged for the patient. If the clinical picture suggests an ongoing ectopic pregnancy, or if the vaginal bleeding is dangerously heavy, the patient will need to be admitted.

Ultrasound assessment

The patient undergoes an ultrasound scan, usually transvaginally. There are several likely outcomes, outlined below with the appropriate management.

If the pregnancy is intrauterine and continues to be viable, reassure the patient and arrange either a booking or follow-up antenatal appointment within 2 weeks.

If viability is uncertain, usually because the pregnancy may be too early for proper assessment, a rescan should be booked in 1–2 weeks’ time.

In a case where there are no retained products, the patient needs to be reviewed and the certainty of the previous diagnosis of pregnancy re-evaluated. If an intrauterine pregnancy has not previously been confirmed, then serial hCG monitoring is needed to ensure that it is decreasing consistent with a miscarriage.

In a case where there is suspicion of an ectopic pregnancy there should be an empty uterus, possible fluid in the pouch of Douglas and an adnexal mass. A heart beat may be apparent within this adnexal mass.

In incomplete/inevitable miscarriages, the majority of women can be managed conservatively in the first instance and this should be discussed with the patient. Expectant management of miscarriage in selected cases is successful in approximately 80% of women. When there is a missed miscarriage, or significant retained products, complete miscarriage is less likely. If there is any suspicion of molar pregnancy, then the patient is not suitable for expectant management and should be referred for an ERPC so that histology is obtained.

Medical management of miscarriage involves administration of prostaglandins, often preceded by mifepristone, and antiprogestogen. This is suitable for women who choose this option.

All women who miscarry should be warned of the signs and symptoms of pelvic infection so that they can seek treatment promptly.

If the patient opts for conservative management, she should return in 1 week’s time for repeat scan. If there are still retained products on the repeat scan, or it appears on initial assessment that ERPC is likely to be required, the patient can have an elective ERPC arranged.

Biochemical

βhCG is a very sensitive marker of pregnancy. Levels in the blood will generally double within 48 hours with a viable intrauterine pregnancy, unlike an ectopic pregnancy, which is discussed later.

Complications

• Haemorrhage or infection if tissue is retained

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