Placentation in SCD

• In a recent study on placentation in SCD (169), of the 72 placentas from women with SCD and pregnancies of more than 20 weeks for which histopathology was available, 50 (69%) had placental pathology and 29 (40%) had MVM. In non-SCD healthy pregnancies, MVM is found in 7–8% of placentas. Outside of SCD, MVM has been linked to conditions associated with placental insufficiency, such as pre-eclampsia. The presence of MVM was associated with adverse pregnancy outcomes (attributable to placental insufficiency), including small for gestational age, iatrogenic preterm birth, stillbirth. These outcomes were seen in 79% of women with MVM, while the risk of adverse outcomes in a low-risk pregnant population with MVM has been reported at ~47% (170). The study authors proposed that the high rates of MVM observed may suggest factors inherent in SCD, that remain as yet unidentified, may potentiate the placental disease sometimes present in unaffected healthy women. Early birth in the general pregnant population
• WHO recommends induction of labour for women who are known with certainty to have reached 41 weeks of gestation (moderate certainty) (174). Routine induction of labour, for women with uncomplicated pregnancies, at less than 41 weeks is not recommended (low certainty) (174). Decision making about timing of birth in women with SCD
• Decisions about the timing of birth need to reflect all aspects of the woman’s pregnancy including other pre-existing conditions and the potential for maternal or neonatal complications such as pre-eclampsia or growth restriction.
• Planned early term birth (between 37 and 38 completed weeks of gestation) may be a consideration when:
• gestational age can be accurately assessed
• the facility is sufficiently resourced to provide care for the mother and newborn (including management of labour and birth, and potential maternal or newborn complications). Factors influencing optimal timing of birth
• The GDG acknowledged that different clinical contexts and individual situations may influence the optimal timing of birth. These include:
• recurrent acute vaso-occlusive pain crisis at or after 34 weeks’ gestation
• admission for moderate to very severe acute chest syndrome at or after 34 weeks’ gestation
• fetal growth restriction
• settings where there is limited availability of blood for transfusion or other resources that may be necessary if complications arise post induction.