At 3-4 weeks of pregnancy, the breast changes include:

Correct Answer: C

Rationale: At 3-4 weeks of pregnancy, breast changes commonly involve tenderness due to hormonal fluctuations. Darkening of the nipple (Choice A) typically occurs later in pregnancy. Prickling, tingling sensations (Choice B) are more associated with early pregnancy due to increased blood flow to the breast area. Colostrum production (Choice D) usually begins later in pregnancy, closer to the end of the third trimester.

Correct Answer: B

Rationale: Incomplete abortion is characterized by an open os, which means that the cervix is dilated, allowing for passage of tissue. This condition typically presents with heavy bleeding as parts of the products of conception are expelled. Severe cramping may also be present due to uterine contractions. Therefore, the correct characteristic of incomplete abortion is an open os (Choice B). Choices A, C, and D are incorrect as heavy bleeding and severe cramping are symptoms associated with incomplete abortion, but they do not specifically define it, and light bleeding is not characteristic of incomplete abortion.

Correct Answer: A

Rationale: During an ectopic pregnancy, a rupture in the ampullary portion of the tube is frequent. This is due to the increased pressure within the fallopian tube as the embryo grows, leading to the rupture of the tube. Choices B, C, and D are incorrect as they do not accurately describe the common occurrence of rupture in this specific part of the tube during an ectopic pregnancy.

Correct Answer: B

Rationale: The correct answer is B: Haemorrhage. Haemorrhage is a leading cause of maternal mortality due to excessive bleeding during childbirth. While conditions like pre-eclampsia, sepsis, and obstructed labor can also be serious complications during pregnancy and childbirth, they are not the primary cause of maternal mortality worldwide.

Correct Answer: C

Rationale: During pregnancy, the layers of endometrium include decidua compacta, decidua spongiosum, and decidua basalis. Decidua functionalis is the layer that sheds during menstruation and regenerates each cycle, not a layer of the endometrium during pregnancy. Therefore, choice C is the correct answer. Decidua compacta is the layer closest to the conceptus, decidua spongiosum is the middle layer, and decidua basalis is the layer adjacent to the myometrium.