Abdominal pain in pregnancy may be divided into causes which occur early, late or at any point.
| Cause | Notes |
|---|---|
| Ectopic pregnancy | This is the single most important cause of abdominal pain to exclude in early pregnancy0.5% of all pregnancies are ectopic |
Risk factors (anything slowing the ovum's passage to the uterus) • damage to tubes (salpingitis, surgery) • previous ectopic • IVF (3% of pregnancies are ectopic) A typical history is a female with a history of 6-8 weeks amenorrhoea who presents with lower abdominal pain and later develops vaginal bleeding • lower abdominal pain: typically the first symptom. Pain is usually constant and may be unilateral. Due to tubal spasm • vaginal bleeding: usually less than a normal period, may be dark brown in colour • history of recent amenorrhoea: typically 6-8 weeks from start of last period; if longer (e.g. 10 wks) this suggest another causes e.g. inevitable abortion • peritoneal bleeding can cause shoulder tip pain and pain on defecation / urination | | Miscarriage | Threatened miscarriage • painless vaginal bleeding occurring before 24 weeks, but typically occurs at 6 - 9 weeks • cervical os is closed • complicates up to 25% of all pregnancies
Missed (delayed) miscarriage • a gestational sac which contains a dead fetus before 20 weeks without the symptoms of expulsion • mother may have light vaginal bleeding / discharge and the symptoms of pregnancy which disappear • when the gestational sac is > 25 mm and no embryonic/fetal part can be seen it is sometimes described as a 'blighted ovum' or 'anembryonic pregnancy'
Inevitable miscarriage • cervical os is open • heavy bleeding with clots and pain
Incomplete miscarriage • not all products of conception have been expelled |
| Cause | Notes |
|---|---|
| Labour | Regular tightening of the abdomen which may be painful in the later stages |
| Placental abruption | Placental abruption describes separation of a normally sited placenta from the uterine wall, resulting in maternal haemorrhage into the intervening space |
| Occurs in approximately 1/200 pregnancies |
Clinical features • shock out of keeping with visible loss • pain constant • tender, tense uterus • normal lie and presentation • fetal heart: absent/distressed • coagulation problems • beware pre-eclampsia, DIC, anuria | | Symphysis pubis dysfunction | Ligament laxity increases in response to hormonal changes of pregnancy Pain over the pubic symphysis with radiation to the groins and the medial aspects of the thighs. A waddling gait may be seen | | Pre-eclampsia/HELLP syndrome | Associated with hypertension, proteinuria. Patients with HELLP also have haemolysis, elevated liver enzymes and a low platelet count. The pain is typically epigastric or in the RUQ | | Uterine rupture | Ruptures usually occur during labour but occur in third trimester Risk factors: previous caesarean section Presents with maternal shock, abdominal pain and vaginal bleeding to varying degree |
| Cause | Notes |
|---|---|
| Appendicitis | Occurs in 1:1,000-2:1,000 pregnancies, making it the most common non-obstetric surgical emergency |
| Higher morbidity and mortality in pregnancy | |
| Location of pain changes depending on gestation, moving up from the RLQ in the first trimester to the umbilicus in the second and the RUQ in the third | |
| Urinary tract infection (UTI) | 1 in 25 women develop in UTI in pregnancy |
| Associated with an increased risk of pre-term delivery and IUGR |