Obstetrics

Suspected intra-amniotic infection is usually an ascending infection associated with ruptured membranes; it can cause maternal sepsis, fetal compromise and early-onset neonatal infection, so prompt senior assessment, antibiotics and a birth plan are required.

Intrahepatic cholestasis of pregnancy causes pruritus without a primary rash and raised bile acids, usually late in pregnancy; peak bile acids stratify stillbirth risk and guide shared decisions about monitoring and planned birth.

Twin and triplet pregnancy is higher risk than singleton pregnancy; early determination of chorionicity and amnionicity drives surveillance, fetal-medicine referral, preterm-birth prevention and timing and mode of birth.

Preterm labour is suspected or established labour before 37 weeks; management aims to identify true imminent birth, gain safe time for corticosteroids, magnesium neuroprotection and in-utero transfer, and avoid delaying birth when infection, bleeding or fetal compromise makes delivery safer.

Rhesus disease is haemolytic disease of the fetus and newborn caused by maternal IgG alloantibodies crossing the placenta and destroying fetal red cells carrying the corresponding antigen; anti-D disease is largely preventable, whereas established sensitisation requires specialist fetal and neonatal surveillance.

Shoulder dystocia is impaction of a fetal shoulder against the maternal pelvis after the head has delivered, so the shoulders will not follow routine axial traction.

Umbilical cord prolapse is descent of the cord past or alongside the presenting part after membrane rupture, so the presenting part and contractions compress it and fetal oxygenation fails.

Pregnancy and the puerperium increase venous thromboembolism risk through hypercoagulability, venous stasis and vascular injury; suspected deep-vein thrombosis or pulmonary embolism needs prompt objective testing and therapeutic low-molecular-weight heparin unless strongly contraindicated.