First Trimester Bleeding

First trimester bleeding is vaginal bleeding before 13 weeks of pregnancy. Causes include threatened or established miscarriage, ectopic pregnancy, molar pregnancy, subchorionic haematoma and cervical or vaginal lesions. It affects about 20 to 25 percent of pregnancies and matters because ectopic pregnancy and haemorrhage must be excluded in every woman.

• About half of women with threatened miscarriage continue to a live birth.
• Risk factors: previous miscarriage, previous ectopic pregnancy, maternal age above 35 years, smoking, intrauterine contraceptive device in situ, pelvic infection.
• Bleeding with a closed os and a live fetus on scan has a good outlook.

Patients have light to heavy vaginal bleeding, with or without lower abdominal cramps, after a missed period. Examine pulse, blood pressure, abdomen, then perform a speculum examination to check the cervix and os.

• Open os suggests miscarriage in progress; closed os suggests threatened miscarriage or other cause.
• Unilateral pain, shoulder tip pain or collapse suggests ectopic pregnancy.
• Differential diagnosis: threatened miscarriage, inevitable or incomplete miscarriage, ectopic pregnancy, molar pregnancy, cervical ectropion or polyp, cervical cancer.
• Complications: haemorrhagic shock, anaemia, sepsis, pregnancy loss, Rhesus alloimmunisation, psychological distress.

The approach is to assess stability, confirm the pregnancy, locate it and identify the cause.

• Urine pregnancy test, haemoglobin, blood group and Rhesus status; cross-match 2 units if bleeding is heavy.
• Transvaginal ultrasound: intrauterine sac with yolk sac or embryo, fetal heart activity from a crown rump length of 7 mm, empty uterus, adnexal mass or free fluid.
• Serum hCG at 0 and 48 hours if no pregnancy is located; a rise of at least 49 percent in 48 hours suggests a viable intrauterine pregnancy.
• Speculum examination to exclude a cervical or vaginal cause; high vaginal swab if discharge or infection is suspected.
• Where ultrasound is unavailable, use clinical findings and refer any woman with pain, shock or an adnexal mass.

The principle is to stabilise the patient, exclude ectopic pregnancy and manage the cause.

• Supportive: reassure; rest as comfortable; insert two large-bore cannulae and give Ringer's lactate 1 litre over 30 minutes if bleeding is heavy; transfuse if haemoglobin is below 7 g/dL or there is shock; no vaginal douching or intercourse while bleeding.
• Pharmacological: paracetamol 1 g oral 6-hourly as needed (maximum 4 g in 24 hours); for a viable pregnancy with bleeding and at least one previous miscarriage, give micronised progesterone 400 mg vaginally twice daily until 16 weeks; for incomplete miscarriage give misoprostol 600 micrograms oral as a single dose; for infection give ampicillin 2 g IV 6-hourly plus gentamicin 5 mg/kg IV once daily plus metronidazole 500 mg IV 8-hourly; for ectopic pregnancy give methotrexate 50 mg/m2 IM as a single dose in stable women with hCG below 5000 IU/L, otherwise surgery.
• Procedures: manual vacuum aspiration for incomplete miscarriage with heavy bleeding up to 12 weeks size; laparoscopy or laparotomy for ruptured ectopic pregnancy.
• Special groups: Rhesus negative women give anti-D immunoglobulin 250 IU IM within 72 hours of heavy bleeding or any evacuation.
• Red flags: heavy bleeding soaking more than 2 pads in an hour, systolic blood pressure below 90 mmHg, pulse above 100 per minute, severe or unilateral pain, shoulder tip pain, fever above 38 degrees Celsius.
• Follow-up: review in 1 week; repeat scan at 7 to 10 days if viability is uncertain; urine pregnancy test at 3 weeks after miscarriage; book antenatal care if the pregnancy continues.