Early Pregnancy Bleeding

Last updated: April 25, 2025

Table Of Contents

Overview
General Management of Early Pregnancy Bleeding
Complications of Early Pregnancy Bleeding

Overview

Early pregnancy bleeding is per vaginal bleeding before viability (WHO < 20 weeks gestation date or < 500 g fetal weight)

Approximately 25% of pregnancie s experience bleeding in the first trimester. Most women need to be reassured since 50% of the time the pregnancy will go on uncomplicated. Lower abdominal pain and heavy bleeding are associated with an increased risk of pregnancy loss. The most common cause of early pregnancy bleeding is miscarriage, and the vast majority of these losses are due to chromosomal anomalies. Every patient presenting with early pregnancy bleeding should get their blood grouped (and possibly crossmatched), and a sterile speculum exam.

Important first steps in the management of first-trimester bleeding (or bleeding after secondary amenorrhoea) include IV fluids, physical exam + sterile speculum exam, quantitative B-hCG, Complete Blood Count, and transvaginal ultrasound. hCG normally takes 2-4 weeks to clear after evacuation.

Progesterone level of <6 ng per mL (19.1 nmol per L) reliably excludes a viable pregnancy (with a Negative Predictive Value of 99%)

Differentials for early pregnancy bleeding
- Ectopic pregnancy
- Implantation bleeding
- Threatened miscarriage (50% will go on to have a normal pregnancy)
- Miscarriage
  - Inevitable miscarriage
  - Incomplete miscarriage
  - Complete miscarriage
  - Missed miscarriage
- Molar pregnancy
- Gynaecological causes:
  - Vulvar, vagina, or cervical trauma
  - Cervical polyp
  - Cervical ectopia
  - Cervical cancer
  - Trichomoniasis
  - Candidiasis
  - Venereal warts
What are the possible causes of pallor in a patient with early pregnancy bleeding?
- Vasovagal shock
- Hypovolemic shock
- Anemia
- Septic shock

General Management of Early Pregnancy Bleeding

Physical examination
- Bimanual exam: to feel for masses e.g. adnexal mass, cervical motion tenderness,
- Sterile Speculum exam
  - Check whether the cervical os is dilated or closed
  - Look for clots or products of conception
  - Rule out vulvar, vaginal, or cervical trauma
Investigations
- Quantitative B-hCG: compare past and future measurements. Should double every 48 hours. Compared to estimated dates on LMP
  - A normal pregnancy with serum hCG > 1,500IU/L should be able to be confirmed as intrauterine on transvaginal ultrasound
- CBC: to evaluate blood loss
- Transvaginal ultrasound: to visualize the fetus
  - Gestational sac visible at 5 weeks
  - Yolk sac and fetal pole visible 5-6 weeks
  - Fetal heart motion (visible at 6-7 weeks LMP): viable fetus
  - Ectopic pregnancy: positive hCG with no evidence of intrauterine pregnancy
- PT/PTT
- Blood type and cross-match
- Rh status: established in any woman presenting with FTB/amenorrhoea
When is RhoGAM (anti-D) recommended?
- All Rh-negative women who have undergone a surgical procedure to manage a miscarriage or ectopic pregnancy (to reduce the risk of isoimmunization since these patients are bleeding)
- The Kleihauer test is not needed to quantify fetomaternal hemorrhage during the first trimester

Complications of Early Pregnancy Bleeding

What are some of the complications associated with a threatened abortion?
- Later complications in pregnancy e.g. Abruption placentae
- First trimester bleeding in subsequent pregnancies
Complications of early pregnancy bleeding
- Pregnancy loss (progression to inevitable, incomplete, complete, missed abortion)
- Heavy bleeding (≥ 1-2 pads per hour for 2 hours)
- Retained POC
- Endometritis
- Septic abortion

Reference Intervals ›

Biochemistry

ACTH	P: <80 ng/L
ALT	P: 5–35 U/L
Albumin	P: 35–50 g/L
Aldosterone	P: 100–500 pmol/L
Alk. phosphatase	P: 30–130 U/L
α-Amylase	P: 0–180 IU/dL
α-Fetoprotein	S: <10 kU/L
Angiotensin II	P: 5–35 pmol/L
ADH	P: 0.9–4.6 pmol/L
AST	P: 5–35 U/L
Bicarbonate	P: 24–30 mmol/L
Bilirubin	P: 3–17 μmol/L
BNP	P: <50 ng/L
CRP	P: <10 mg/L
Calcitonin	P: <0.1 mcg/L
Calcium (ionized)	P: 1.0–1.25 mmol/L
Calcium (total)	P: 2.12–2.60 mmol/L
Chloride	P: 95–105 mmol/L
Cholesterol	P: <5.0 mmol/L
VLDL	P: 0.128–0.645 mmol/L
LDL	P: <2.0 mmol/L
HDL	P: 0.9–1.93 mmol/L
Cortisol AM	P: 450–700 nmol/L
Cortisol Midnight	P: 80–280 nmol/L
CK ♂	P: 25–195 U/L
CK ♀	P: 25–170 U/L
Creatinine	P: 70–100 μmol/L
Ferritin	P: 12–200 mcg/L
Folate	S: 2.1 mcg/L
FSH	P: 2–8 U/L ♂; >25 menopause
GGT ♂	P: 11–51 U/L
GGT ♀	P: 7–33 U/L
Glucose (fasting)	P: 3.5–5.5 mmol/L
Growth hormone	P: <20 mu/L
HbA1C (DCCT)	B: 4–6%
HbA1C (IFCC)	B: 20–42 mmol/mol
Iron ♂	S: 14–31 μmol/L
Iron ♀	S: 11–30 μmol/L
Lactate (venous)	P: 0.6–2.4 mmol/L
Lactate (arterial)	P: 0.6–1.8 mmol/L
LDH	P: 70–250 U/L
LH	P: 3–16 U/L
Magnesium	P: 0.75–1.05 mmol/L
Osmolality	P: 278–305 mosmol/kg
PTH	P: 0.8–8.5 pmol/L
Potassium	P: 3.5–5.3 mmol/L
Prolactin ♂	P: <450 U/L
Prolactin ♀	P: <600 U/L
PSA	P: 0–4 mcg/mL
Protein (total)	P: 60–80 g/L
Red cell folate	B: 0.36–1.44 μmol/L
Renin (erect)	P: 2.8–4.5 pmol/mL/h
Renin (recumbent)	P: 1.1–2.7 pmol/mL/h
Sodium	P: 135–145 mmol/L
TBG	P: 7–17 mg/L
TSH	P: 0.5–4.2 mU/L
T4	P: 70–140 nmol/L
Free T4	P: 9–22 pmol/L
TIBC	S: 54–75 μmol/L
Triglycerides	P: 0.50–2.3 mmol/L
T3	P: 1.2–3.0 nmol/L
Troponin T	P: <0.1 mcg/L
Urate ♂	P: 210–480 μmol/L
Urate ♀	P: 150–390 μmol/L
Urea	P: 2.5–6.7 mmol/L
Vitamin B12	S: 0.13–0.68 nmol/L
Vitamin D	S: 50 nmol/L

Arterial Blood Gases

pH	7.35–7.45
PaCO₂	4.7–6.0 kPa
PaO₂	>10.6 kPa
Base excess	±2 mmol/L

Urine

Cortisol (free)	<280 nmol/24h
Hydroxyindole acetic acid	16–73 μmol/24h
Hydroxymethylmandelic acid	16–48 μmol/24h
Metanephrines	0.03–0.69 μmol/mmol cr.
Osmolality	350–1000 mosmol/kg
17-Oxogenic steroids ♂	28–30 μmol/24h
17-Oxogenic steroids ♀	21–66 μmol/24h
17-Oxosteroids ♂	17–76 μmol/24h
17-Oxosteroids ♀	14–59 μmol/24h
Phosphate (inorganic)	15–50 mmol/24h
Potassium	14–120 mmol/24h
Protein	<150 mg/24h
Protein/creatinine ratio	<3 mg/mmol
Sodium	100–250 mmol/24h

Haematology

WCC	4.0–11.0 ×10⁹/L
RBC ♂	4.5–6.5 ×10¹²/L
RBC ♀	3.9–5.6 ×10¹²/L
Hb ♂	130–180 g/L
Hb ♀	115–160 g/L
PCV ♂	0.4–0.54 L/L
PCV ♀	0.37–0.47 L/L
MCV	76–96 fL
MCH	27–32 pg
MCHC	300–360 g/L
RDW	11.6–14.6%
Neutrophils	2.0–7.5 ×10⁹/L (40–75%)
Lymphocytes	1.0–4.5 ×10⁹/L (20–45%)
Eosinophils	0.04–0.44 ×10⁹/L (1–6%)
Basophils	0–0.10 ×10⁹/L (0–1%)
Monocytes	0.2–0.8 ×10⁹/L (2–10%)
Platelets	150–400 ×10⁹/L
Reticulocytes	0.8–2.0% / 25–100 ×10⁹/L
Prothrombin time	10–14 s
APTT	35–45 s

Paediatric

Pulse Rate (bpm)
Neonate	140–160
Infant <1yr	120–140
1–5 years	110–130
5–12 years	80–120
>12 years	70–100
Respiratory Rate (tachypnoea)
0–2 months	≥60/min
2–12 months	≥50/min
1–5 years	≥40/min
>5 years	≥30/min
Blood Pressure (mmHg)
Term	65/45
1 year	75/50
4 years	85/60
8 years	95/65
10 years	100/70
Weight Formulas
3–12 months	(a + 9)/2 kg
1–6 years	2a + 8 kg
>6 years	(7a − 5)/2 kg
Haemoglobin (g/dL)
Term newborn	13–20
1 month	11–18
2 months	10–15
1–2 years	10–13
>2 years	11–14
MUAC (6 months–5 years)
Obese	>17.5 cm
Normal	13.5–17.4 cm
At risk	12.5–13.4 cm
Moderate malnutrition	11.5–12.4 cm
Severe malnutrition	<11.5 cm
Developmental Milestones
Social smile	1.5 months
Head control	4 months
Sits unsupported	7 months
Crawls	10 months
Stands unsupported	10–12 months
Walks	12–13 months
Talks	18 months
CSF WBC (/mm³)
Term newborn	0–25
>2 weeks	0–5

Calculator ›

Overview

General Management of Early Pregnancy Bleeding

Complications of Early Pregnancy Bleeding

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