In this post I will mention the most common and must-know causes of abdominal pain in pregnancy which is a very common complaint during gestation. I will also mention certain salient points which will be helpful in the differential diagnosis.
1. Implantation Bleeding. There is a mild abdominal pain 6-12 days after conception along with a small amount of vaginal bleeding called spotting. Be careful so as not to confuse this bleeding with the menstrual bleeding.
2. Ectopic Pregnancy. This is the leading cause of first trimester mortality of the foetus. If there is a serum HCG level more than 2400 mIU/ml (The discriminatory zone is 1500-2400mIU/ml) and on USG there is no gestational sac in the uterus, then you should strongly suspect this. The most common sites are Tubal, Ovarian, Interstitial, Cervical.
3. Spontaneous Abortion. It is common in the early pregnanacy( upto 20 weeks) and is divided into 4 stages: Threatened, Inevitable, Incomplete, Complete. If there is vaginal bleeding without cervical dilatation or any change in cervical consistency, then it is Threatened abortion, if the cervix is dilated, it is Inevitable; if some products of conception are discharged per vaginally, it is incomplete abortion.
4. Abruptio Placentae. It is due to premature separation of placenta from its implantation site causing vaginal bleeding and pain due to uterine cramps caused by myometrial irritation. In some cases there is no vaginal bleeding, and we call those Concealed abruption. If the abruption is large enough to cause uteroplacental insufficiency the fetus is at risk. And the mother is at risk of haemorrhagic shock.
5. Ovarian Cyst
6. Ovarian Torsion
8. Uterine leiomyomas (Fibroids)
9. HELLP Syndrome. Haemolysis, Elevated liver enzymes, Low platelets syndrome is a complication of Preeclampsia characterized by nausea, vomiting and right upper quadrant pain and tenderness. If this condition has progressed, there is risk of seizures and in the worst case hepatic rupture causing hypovolemic shock and severe pain. Peripheral blood smear will show schistocytes and low platelets.
10. Cholelithiasis. This condition will have characteristic biliary colic, i.e., intermittent right upper quadrant pain associated with nausea and vomiting.
12. UTI. There will be suprapubic pain with dysuria, frequency and urgency.
14. Round Ligament Pain. Enlargement of uterus during pregnancy leads to traction in the round ligament which pulls on the nearby nerve fibres causing sharp pain; such a pain can also be caused by round ligament spasm or cramps. This pain is usually present on the right side because of the dextro-deviation of the uterus and managed by acetaminophen and exercise.