Obstetrics Quiz

The second trimester begins at 13 weeks and ends at 28 weeks.

IUGR can occur for a large number of reasons. Smoking accounts for around 30-40% of IUGR cases.

The correct way to calculate the EDD is to add 9 months and 1 week onto the first day of the last normal menstrual period. This method may not be reliable if a woman is unsure about when her last menstrual period was. As a result ultrasound is used to more accurately date pregnancies.

Hyperemesis gravidarum is a severe form of morning sickness in which women suffer from excessive nausea and vomiting which prevents them from taking in adequate amounts of food and water. It is thought to be caused by high levels of circulating HCG. This is supported by the fact that it's more common in multiple pregnancy and also tends to only affect women during the first 12 weeks of pregnancy.

Most women will become aware of fetal movements around 18-20 weeks. However, if a woman has had previous pregnancies they often notice movements earlier (around 15-18 weeks).

All of the above are potential causes of PPH with uterine atony being the most common. Coagulopathy is a rare cause, accounting for around 1% of PPH.

The most common cause of PPH is uterine atony, however, retained placenta and vaginal lacerations also account for a significant proportion of PPH. Uterine atony describes a state in which the uterus can no longer effectively contract. Because the uterus cannot contract the blood vessels which were supplying the placenta are not compressed and can, therefore, bleed profusely. A uterus can become atonic for a number of reasons such as prolonged labour, large baby, multiple pregnancy and retained placenta.

Linea nigra can be seen on this image. This occurs in around 3/4 of pregnancies. It's described as a vertical line of increased pigmentation running down the centre of the pregnant abdomen. The increased pigmentation occurs over the linea alba which is stretched during pregnancy to accommodate the developing foetus.

Misoprostol is inserted vaginally and causes effacement of the cervix in addition to uterine contraction.

The third trimester starts at 29 weeks and ends at 40 weeks.

The first trimester refers to the first 12 weeks of pregnancy.