Pregnancy: Abdominal Pain

• Introduction to abdominal pain and pregnancy
• Clinical examination
• Questions you should ask your doctor
• Obstetric causes of abdominal pain during pregnancy
  • Ectopic pregnancy
  • Miscarriage
  • Placental abruption
  • Placenta praevia
  • Molar pregnancy
  • Premature labour

Introduction to abdominal pain and pregnancy

Abdominal pain is a common symptom seen in pregnancy, and has many different causes. During pregnancy, abdominal pain may result from obstetric or gynaecologic disorders related to the pregnancy, or it may be due to other causes not related to the pregnancy. Identifying the cause of the pain becomes more challenging in pregnancy as the pregnancy may alter the signs and symptoms of many abdominal disorders. In addition,  the use of diagnostic investigations (e.g. x-rays) may be limited in pregnancy due to concerns about the safety of the foetus. Foetal safety concerns also limit the available therapies for the treatment of abdominal pain during pregnancy.

Clinical examination

Abdominal pain in pregnancy could be the result of a large number of conditions, so a careful history is taken and a clinical examination performed. You should provide your general practitioner/midwife/obstetrician with as many details as you can regarding:

• Site of the pain: Can you point to a specific area or is it widespread?
• Character of the pain: Is it an ache, a sharp pain, a cramping pain, or a pressure feeling?
• Onset: How did it begin?
• Radiation: Does the pain travel anywhere else, such as down your leg or to your back?
• Pain intensity: On a scale of 1 to 10, how would you rate the pain intensity?
• Precipitating factors: What makes the pain worse?
• Relieving factors: What makes the pain better?
• Duration: How long have you experienced this pain?

Depending on your presentation and gestation, the clinical examination will vary but may include:

• Recording of your vital signs: Measurements including pulse, blood pressure and temperature.
• Abdominal palpation: To localise any tenderness/masses, as well as to determine the approximate size and position of the baby.
• Speculum examination: Similar to the method of performing a PAP smear, can enable the doctor to assess your cervix.

It may also be necessary for your doctor to order some blood tests and/or an ultrasound.

Questions you should ask your doctor

After the doctor has taken your history and performed an examination, some questions you might like to ask include:

• What do you think the most likely cause of this pain is?
• Is this an emergency situation – can this harm the life of myself or my baby?
• What effect will this have on my pregnancy?
• What effect will my pregnancy have on this condition/disease?
• What are the side effects of any prescribed medications and can they harm my baby?
• Do I require any follow up?
• When should I become concerned and seek further medical attention?

Obstetric causes of abdominal pain during pregnancy

Some common obstetric causes of abdominal pain during pregnancy are summarised below.

Ectopic pregnancy

Occurring in 1.5–2.0% of pregnancies, ectopic pregnancy involves the implantation of a fertilised ovum outside of the uterus. Implantation most commonly takes place in the fallopian tubes and less commonly in the cervix, ovary, abdomen or scar from a caesarean section.Risk factors include: Pelvic inflammatory disease; Previous surgery to the fallopian tubes; Previous ectopic pregnancy; Cigarette smoking; Age > 35; and Many lifetime sexual partners.

This condition is potentially life threatening and needs to be excluded in all sexually active women presenting with vaginal bleeding and positive pregnancy test. Initially, vaginal bleeding may be the only sign, but later the woman may experience cramping abdominal or pelvic pain and shock.

For more information, see Ectopic Pregnancy.

Miscarriage

Miscarriage affects up to 1 in 4 women throughout their lifetime. It is defined as the loss of a foetus at less than 20 weeks gestation.

Approximately 75% of miscarriages occur prior to 10 weeks gestation. The majority are the result of a chromosomal abnormality of the foetus. Second trimester miscarriages are much less frequent, accounting for only 1–2%.

If early pregnancy loss has been confirmed by the appropriate investigations, there are three management options:

1. Surgical removal of the products of conception by dilatation and curettage;
2. Medicinal management with the insertion of prostaglandins in tablet form into the vagina; or
3. Expectant management where no treatment is given and repeat investigations performed after a period of time to ensure that all the products of conception have been passed.

 

 

Placental abruption

Abruptio placentae, also known as placental abruption, is defined as bleeding from the premature separation of a normally located placenta, and occurs in approximately 1 in 100 pregnancies. In most cases (70%), blood loss from the vagina is evident; however, in 30% of cases, the bleeding is located between the placenta and uterine wall and there is no blood loss evident from the vagina. Risk factors include: Preeclampsia; Blunt abdominal trauma; External cephalic version; Smoking; Cocaine use; Multiple pregnancy; Increasing maternal age; Increasing parity; Polyhydramnios; and Previous history of placental abruption.

Presentation is typically of sudden onset abdominal pain with or without signs of shock. Stillbirth is apparent in approximately 30% of cases.

Diagnosis is made on clinical grounds, with ultrasound having a very low detection rate.

Management includes resuscitation and stabilisation of the shocked woman. Further management is dictated by several factors, including severity of blood loss, maternal and foetal condition, gestational age, parity and state of the cervix.

For more information, see Placental Abruption.

Placenta praevia
A diagnosis of placenta praevia is made when part of or the entire placenta is inserted into the lower segment of the uterus. This may totally (placenta praevia major) or partially (placenta praevia minor) cover the internal cervical os (opening of the cervix). As well as causing bleeding during the pregnancy, it may cause bleeding during labour and delivery, or in the postpartum period. The bleeding may be severe and life threatening. A normal vaginal delivery is usually not possible with cases of placenta previa major.

Risk factors include:

• Increasing parity;
• Increasing maternal age;
• Abnormalities in the uterus;
• Smoking;
• Cocaine abuse;
• Multiple pregnancies;
• Previous placenta praevia;
• Caesarean section;
• Termination of pregnancy; and
• Intrauterine surgery.

Presentation is typically painless, unprovoked vaginal bleeding, which may vary between minor to massive bleeding.

Diagnosis can be made with transvaginal ultrasound, which is the most accurate and safest method of diagnosis.

Management is largely dependant on the wellbeing of both the mother and the foetus, the degree of blood loss, degree of placenta praevia and gestational age.

For more information, see Placenta Praevia.

Molar pregnancy

Molar pregnancy, also known as hydatidiform mole, is a name given to a range of pregnancy-associated tumours. They are the result of abnormal fertilisation and, while most are benign, some may be malignant.

Molar pregnancy usually presents as:

• Painless vaginal bleeding;
• Passage of vesicles;
• Exaggerated pregnancy symptoms with or without excessive vomiting;
• Hyperthyroidism;
• Anaemia;
• Large uterus for dates;
• Raised bHCG; and
• Multiple grape-like vesicles distending the uterus, visible either to the naked eye or via ultrasound.

Management of a molar pregnancy typically involves surgical removal by dilatation and curettage. A chest radiograph may also be required. Following the procedure, your bHCG will need to be monitored closely until they fall below a certain level (< 2 IU/L), and then monthly for six months after that time. It is important that you avoid becoming pregnant for at least six months following this fall in bHCG levels.

For more information, see Molar Pregnancy.

Premature labour

Premature (preterm) labour is defined as the premature onset of uterine contractions that may result in the birth of the foetus before 37 weeks gestation. Symptoms are variable but include:

• Vaginal discharge and/or blood loss;
• Lower abdominal pain;
• Back pain;
• Urinary urgency; and/or
• Vaginal pressure.

Depending on the health of the mother and the foetus, the birth may be delayed to allow for the foetus to continue to mature; transfer to a hospital with appropriate facilities for the birth of a preterm infant; and/or administration of medications to promote foetal lung development.

More information

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For more information about pregnancy, including preconception advice, stages of pregnancy, investigations, complications, living with pregnancy and birth, see Pregnancy.

 

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