Pregnancy - red flag symptoms

Red flags to look out for in pregnant women include back pain, bleeding, headaches, hypertension and high fever.

Although GPs have not provided lead maternity care services for many years, studies have demonstrated that pregnant women consult their GP more frequently than non-pregnant women, and that GPs remain important providers of care for women during maternity.

In assessing the pregnant patient, it is important to exclude serious conditions that may warrant investigation or referral, from the normal symptoms of pregnancy.

Pregnancy can exacerbate medical conditions, including fibroid degeneration, ovarian cysts, urinary tract infections, adnexal masses that persist in pregnancy, gastro-oesophageal reflux, gallbladder disease, pre-existing hypertension and constipation. Pregnancy can worsen diabetic control and can cause gestational diabetes. Finally, remember labour as a cause of symptoms, especially in first-time pregnancies.

Red flag symptoms

  • Severe back pain
  • Visual changes, such as blurred vision or diplopia
  • Headaches
  • New onset limb swelling
  • Shoulder tip pain
  • Acute shortness of breath
  • Leg swelling and pain
  • Intractable vomiting
  • Unilateral pain in pelvis or lower abdomen
  • Vaginal bleeding or increased discharge
  • Epigastric pain
  • Acute pleuritic chest pain
  • Rigid/tender uterus
  • High fever
  • Hypertension
  • Severe itching
  • Reduced foetal movements
  • New onset thirst or polyuria

Possible causes

  • Premature labour
  • Miscarriage
  • Ectopic pregnancy
  • Placental abruption
  • Pre-eclampsia
  • Obstetric cholestasis
  • Pyelonephritis
  • DVT/PE
  • Hyperemesis gravidarum
  • Placenta praevia
  • Gestational diabetes

Urgent referral

It is important a pregnant woman be urgently referred to the obstetric team if she experiences:

  • Severe abdominal, pelvic, or unusual back pain
  • Fainting or lightheadedness
  • The baby moving much less or having sudden violent movements
  • A fever and suggestion of sepsis
  • A rapid pulse or lowered BP, indicating shock
  • Visual changes, headaches and swelling suggestive of pre-eclampsia
  • Acute shortness of breath, with or without leg swelling and pain
  • Rigid/tender uterus
  • Acute pleuritic chest pain
  • Vaginal bleeding or blood-stained discharge (see ‘Early vaginal bleeding’ page for more information)

Investigations in primary care

Urinalysis may be done in primary care, depending on the urgency of the situation, to exclude a UTI or highlight proteinuria, suggestive of pre-eclampsia.

Blood tests can be useful, to identify infection or anaemia for example. Doppler ultrasound of foetal heart rate may be performed.

Early vaginal bleeding and ectopic pregnancy

One in four pregnancies experience bleeding, most commonly between the ninth and twelfth weeks, which can be part of a normal pregnancy. Painless spotting during early pregnancy is often caused by physiological embryo implantation.

Bleeding in the first trimester can also be a sign of an ectopic pregnancy, typically occurring around the sixth week. A woman presenting with unilateral lower abdominal pain and vaginal bleeding should be investigated for ectopic pregnancy.

A history of past ectopic pregnancy, sexually transmitted infections, smoking and fallopian tube surgery increases risk of ectopic pregnancy.

ymptoms including diarrhoea, vomiting, bowel pain and/or referred shoulder tip pain (caused by internal bleeding irritating the phrenic nerve) make the diagnosis more likely. In women not known to be pregnant, with a delayed period and bleeding that is different from a normal period (heavier or lighter and often darker) an ectopic pregnancy should be considered.

Miscarriage and antepartum haemorrhage

Miscarriage or potential miscarriage (loss of pregnancy before 24 weeks gestation) may be indicated by bleeding, passage of clots and especially when combined with persistent back or abdominal pain.

Most miscarriages occur in the first trimester and it may affect up to a fifth of recognised pregnancies. A woman who has had more than three unexplained miscarriages should be referred for further investigation.

Antepartum haemorrhage

Antepartum haemorrhage - bleeding from or into the genital tract that occurs from 24 weeks, can be a result of placenta praevia, placental abruption and local causes.

Bleeding accompanied by continuous pain with a hard, tender uterus may indicate placental abruption.


Pre-eclampsia typically, but not exclusively, occurs after the twentieth week of gestation. It is associated with elevated blood pressure (>140/90mmHg) and proteinuria in a previously normotensive woman.

NICE guidance states that blood pressure measurement and urinalysis should be carried out at each antenatal visit to screen for pre-eclampsia.

Clinical suspicion should be aroused with presenting symptoms including epigastric pain, severe headaches, new onset visual problems or sudden onset oedematous swelling.

Pre-eclampsia is a multisystem disorder having the potential to affect all the systems of the body, including the placenta and the baby. The prime pathology is an abnormal relationship between the maternal system and the trophoblastic system.

Its incidence is greater in diabetic pregnancies and multiple pregnancies. It is generally a disease of women in their first pregnancy, and more common among women aged over 35.

Obesity is a risk factor for hypertension, but not for pre-eclampsia. Women who have developed hypertension while taking a combined oral contraceptive are at risk of pre-eclampsia, as are those with autoimmune disorders.

The incidence is lower among women who smoke

HELLP syndrome - haemolysis (H), elevated liver enzymes (EL) and low platelet count (LP) - is a life-threatening condition that can occur in those with pre-eclampsia.

Hyperemesis gravidarum

Nausea and vomiting are common in pregnancy, affecting up to 90% of pregnant women and usually requiring advice and reassurance, although 35% of these women may require anti-emetic medication such as cyclizine.

The severe intractable nausea and vomiting of hyperemesis gravidarum (HG), usually between eight and twelve weeks, affects up to 2% of pregnant women. HG can lead to fluid and electrolyte disturbance and marked ketonuria – an indicator for admission for fluid support.

The BMJ Publishing Group’s Clinical Evidence ( states antihistamines are 'beneficial’ in hyperemesis, while cyanocobalamin (vitamin B12) and dietary ginger are `likely to be beneficial’.

Dietary intervention excluding ginger, acupressure, phenothiazines, pyridoxine (vitamin B6), corticosteroids are of unknown effectiveness.

Obstetric cholestasis

Intrahepatic (obstetric) cholestasis generally occurs in the third trimester and affects 0.7% of pregnancies (up to 1.5% of Indian-Asian or Pakistani-Asian origin).

Intense pruritus, without accompanying rash, typically affects the hands and soles. Jaundice can occur with pale stools and dark urine, as can generalised malaise, with symptoms often preceding unexplained elevated AST, ALT and total bile acid levels (the upper limit of normal is 20% lower than non-pregnant levels).

Other causes of liver dysfunction and itching need to be excluded. The condition should settle spontaneously following delivery.

With increased risk of foetal distress, premature birth and intrauterine death, women with a present or past history of obstetric cholestasis should be managed by a consultant-led team.

Leaking fluid and/or contractions

Leaking of fluid per vagina prior to thirty-seven weeks gestation should be assumed to be premature rupture of the membranes and will require monitoring, vigilance over potential infection and preparation for premature delivery.

After 37 weeks, clear amniotic fluid leakage would usually be followed by imminent labour.
Delivery may be very imminent with intense contractions, or the feeling to push or have a bowel movement.

Any of the following, in association with likely labour, indicate a potential life-threatening problem with immediate referral to a consultant-led labour ward necessary:

  • Heavy vaginal bleeding
  • Ruptured waters with protrusion of umbilical cord from the vagina or sensation of something in the vagina
  • Ruptured waters with thick, yellow, green or brown fluid
  • Cessation of baby movements or violent movements
  • Maternal sensation of passing out

Urinary symptoms/vaginal discharge

Urinary infection not responding to antibiotics, refractory candida or other vaginal discharge should all necessitate swabs since certain vaginal infections are associated with pre-term birth and low birth-weight babies.

UTIs can also present with non-specific symptoms in pregnant women. There is an increased risk of pyelonephritis in women with UTIs.

Acute pyelonephritis in pregnancy carries significant risk to the baby, but has reduced in incidence in recent decades as a result of screening for asymptomatic bacteriuria, including urinalysis at each antenatal visit.

In severe cases the mother will have high pyrexia. Babies tolerate fever poorly and death in-utero may occur if the temperature is not brought under control.

Premature labour is also associated with high fevers in the third trimester. The infecting organism is usually a coliform, and antibiotic treatment should be commenced empirically.

Ascending infection is a common cause of sickle cell crises.


An index of suspicion should be raised toward deep vein thrombosis with leg swelling, pain, warmth and/or redness – remembering that the Wells score has not been validated in pregnancy and referral should be based on clinical acumen.

Any sudden difficulty in breathing, chest pain or tightness, or maternal collapse has to include consideration of a pulmonary embolism with prompt medical assessment.


Most accidental falls and minor traumatic injuries in pregnancy are not harmful. However, signs of emotional or physical distress, such as bleeding, amniotic fluid leak or contractions, should prompt obstetric review.

Psychological problems

If a woman has a psychiatric history, they should generally be managed by a consultant-led team, including specialist psychiatric review as part of their antenatal programme.

Symptoms of depression are often reviewed in primary care. Patients are often taking SSRIs and information about these in pregnancy can be found on the Bumps website. You should be vigilant for thoughts of self harm and suicide, with referral as appropriate.

You may have access to a perinatal mental health service.


A febrile patient should prompt investigation and treatment of cause, considering onward referral if signs of sepsis are present, or with associated haemodynamic instability, deteriorating clinical condition, or non-responsiveness to treatment.

  • This article, originally by Dr Matthew West, was reviewed and updated in 2020 by Dr Pipin Singh a GP in Northumberland

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