Twin gestations are generally at increased risk of complications and this risk is further stratified based on the chorionicity ie. number of placentas and amnionicity, the number of amniotic sacs of the gestation. In the given case patient has monochorionic diamniotic twins, which means 1 placenta and 2 amniotic sacs, based on the presence of 2 embryos, a single placenta and a thin intertwin membrane composed of 2 amniotic sacs that meets the placenta at a 90-degree angle (“T sign”). In patients who appear to have a single placenta, the base shape of the intertwin membrane distinguishes between a monochorionic (“T sign”) and fused dichorionic (“lambda sign”) gestation.
Monochorionic twins are at high risk for twin-twin transfusion syndrome (TTTS), which is a complication that can result in heart failure and fetal
eonatal mortality in both twins. In TTTS, unbalanced arteriovenous anastomoses are present between the shared placental vessels that supply the twins, because of these anastomoses, blood from the placental arteries from one twin (donor), which is of high resistance/pressure, is shunted into the placental veins of the other twin (recipient) with low resistance/pressure. This shunting of blood away from the donor twin causes anemia that leads to renal failure, oligohydramnios, low-output heart failure, and fetal growth restriction. In contrast, the shunting of blood toward the recipient twin causes polycythemia, which leads to polyhydramnios, cardiomegaly, high-output heart failure and hydrops fetalis. This in turn makes both twins at high risk for intrauterine and neonatal death.
Mild TTTS is expectantly managed with serial ultrasounds to evaluate for worsening clinical features, whereas moderate-to-severe cases are treated with laser coagulation of the placental anastomoses.

In monozygotic twins, placentation type is determined by timing of the twinning.  Twinning that occurs shortly after fertilization yields a dichorionic diamniotic gestation.  In contrast, the incomplete division (ie, fission) that can lead to conjoined twins occurs later in development and yields a monochorionic monoamniotic gestation. As the twins are in the same sac, monochorionic monoamniotic gestations can be complicated by cord entanglement but not possible in the given case as this patient has diamniotic twins.

Risk factors for placenta accreta, implantation of the placenta directly into the myometrium, include placenta previa and prior uterine surgeries like cesarean delivery, myomectomy, etc

Twin pregnancies are at increased risk of placenta previa (placental tissue that covers the internal cervical os); however, this patient has a fundal placenta, making this complication unlikely.

Monochorionic twin gestations can be complicated by twin-twin transfusion syndrome, which is potentially a fatal condition that results from unbalanced vascular anastomoses between the vessels supplying umbilical cords of each twin.

Cases with spontaneous rupture of membrane before the onset of labour, prior to 37 weeks of gestation is defined as preterm premature rupture of membranes(PPROM). It complicates almost 2-4% of all singleton and 7- 20% of twin pregnancies and is commonly associated with more than 60% of all preterm births.

Management of PPROM In the absence of chorioamnionitis, depends on the gestational age. That is in cases of PPROM before 23 weeks, labor may be induced or the patient be sent home for bed rest and is asked to wait until any signs of spontaneous delivery to start. Between 23 and 34 + 0/7 weeks, the patient should be transferred to a tertiary hospital and be admitted there as it is very important to administer systemic corticosteroids, for the fetal lung to attain maturity. It is also mandatory the patient gets adequate bed rest, cervical and vaginal swabs for microscopy and culture, along with prophylactic antibiotics for prevention of chorioamnionitis.
NOTE –  regardless of the gestational age, chorioamnionitis is said to be an absolute indication for the termination of pregnancy.

In the given case, patient is currently in her 28th week of gestation, so she should be immediately transferred to a tertiary hospital and given systemic steroids to promote fetal lung maturation in case preterm delivery ensues.

The urinary bladder, and most of the urinary structures are lined by epithelium called the urothelium, or the transitional epithelium. This stratified lining is divided into three parts, an apical layer, an intermediate layer and a basal layer. The transitional epithelium is available to stretch to accommodate the increased volume when the bladder is distended, without structural damage.

Blood enters the right atrium of the fetal heart and most passes through the foramen ovale into the left atrium. From there it is pumped through the aorta. The foramen ovale is the major structure for bypassing the fetal pulmonary circulation. Some of the blood in the right atrium does enters the right ventricle and then into the pulmonary artery however most of this passes through the ductus arteriosus into the aorta thus bypassing the fetal pulmonary circulation.

X-rays carry low levels of risk during pregnancy and are not a significant cause for concern if the total exposure to ionising radiation is less than 5 rads throughout the pregnancy; a chest X-ray is about 0.00007 rads. The amount of radiation generated from a chest X-ray is equivalent to 2.4 days of natural background radiation. Non-urgent radiological tests should, however, be avoided between 10-17 weeks gestation as there is a higher risk of central nervous system teratogenesis during this time.

In women of childbearing age, the most likely cause of abnormal vaginal bleeding is pregnancy; thus, the most appropriate initial test would be an hCG level. Once pregnancy has been excluded, patient history would guide further testing. Iatrogenic causes, usually resulting from certain medicines or supplements, are the next most common cause in this age group, followed by systemic disorders. Haemoglobin and haematocrit would be appropriate only if the patient seemed acutely anaemic due to the abnormal bleeding.

Ultrasound findings in early pregnancy can help determine the viability of an intrauterine pregnancy. In the absence of a fetal heartbeat and no visible fetal pole, the mean gestational sac diameter should be measured. A sac diameter of less than 25mm on a transvaginal ultrasound scan is likely an indication of a miscarriage. In the presence of a fetal heartbeat, the crown-rump length should be less than 7mm according to NICE guidelines. Further scans are indicated 14 days later to confirm the diagnosis. The diagnosis of ‘pregnancy of uncertain viability’ is given in situations where there is inadequate ultrasound evidence to diagnose a miscarriage, such as a developing sac but no visualisation of a foetus with a heartbeat.
Ultrasound findings for partial molar pregnancy are an enlarged placenta with multiple diffuse anechogenic patches, while findings in a complete molar pregnancy include an enlarged uterus with multiple small anechogenic spaces (snowstorm appearance), or the bunch of grapes sign representing hydropic trophoblastic villi.

Eisenmenger’s syndrome is one where there is communication between the systemic and pulmonary system, along with increased pulmonary vascular resistance, either to systemic level or above systemic level (right to left shunt). A would-be mother must be informed that to become pregnant would incur a 50% risk of dying. Even if she survives, fetal mortality approaches 50% as well.

– Severe symptomatic aortic stenosis has a mortality in pregnancy of about 20%. Prevention of reduction in preload is necessary in all obstructive cardiac lesions. Balloon valvuloplasty can be done in pregnancy.
– Due to the increased blood volume and cardiac output in pregnancy, mitral stenosis can lead to severe pulmonary oedema. Balloon valvuloplasty can be done in pregnancy.
– Ebstein anomaly is a malformation of the tricuspid valve- It is usually not associated with maternal mortality.
– Atrial-septal defects rarely cause complications in pregnancy, labour, or delivery.

IUS or Intra Uterine System/Device releases progestin. The progestin thickens the cervix, preventing the sperm from penetrating the cervix, and it also causes the uterine lining to become thinner, preventing any implantation. IUS may also prevent excessive bleeding and can help women with fibroids.

At about 8-12 weeks gestation, normal physiological herniation of the fetal bowel occurs. The midgut protrudes into the base of the umbilicus, and undergoes a 90-degree anticlockwise rotation. When the abdominal cavity enlarges enough to fit the developing midgut, the intestines undergo another 180-degree rotation before returning to the abdominal cavity.