The relationship between virtual antenatal care and pregnancy outcomes in a diverse UK inner-city population; A group-based trajectory modelling approach using routine health records

Background The COVID-19 pandemic resulted in major maternity service reconfigurations, particularly an increase in virtual antenatal care (vANC). We aimed to explore the relationship between vANC trajectories over time and pregnancy outcomes. Methods Pregnancy and birth outcome data were obtained pre-pandemic, during the pandemic with, and without lockdowns from the Born in South London (eLIXIR-BiSL) health record data linkage of a multiethnic and deprived UK inner-city population. Antenatal care was characterised by the number of outpatient contacts during six pregnancy epochs: 0–14 + 6, 15 + 0–20 + 6, 21 + 0–27 + 6, 28 + 0–32 + 6, 33 + 0–36 + 6 and ≥ 37 + 0 weeks’ gestation. In each epoch, the proportion of vANC was grouped into quartiles, and group-based trajectory modelling (GBTM) was used to extract vANC trajectories. Adjusted multinominal logistic regression was used to explore relationships between vANC trajectories and pregnancy outcomes. Results Based on 34,114 mother-child dyads (Oct-2018-Jul-2023), GBTM suggested four trajectories of vANC: ‘Trajectory-0’: Stable over pregnancy, and lowest quartile (n = 27,751 pregnancies, 81·3%); ‘Trajectory-1’: High 1st trimester vANC (n = 832, 2·4%); ‘Trajectory-2’: High 2nd trimester vANC (n = 2,410, 7·1%); and ‘Trajectory-3’: High 3rd trimester vANC (n = 3,121, 9·2%). Following adjustment, compared with Trajectory-0, Trajectory-2 had more premature births: (< 37 weeks, adjusted relative risk 1·21, 95% confidence interval 1·02 − 1·44), labour inductions (1·13, 1·02 − 1·25), breech presentation (1·92, 1·02–3·62), and postpartum haemorrhage (1·14, 1·00–1·30). Compared with Trajectory-0, Trajectory-3 had more premature births (< 37 weeks, 1·35, 1·16 − 1·58), elective (1·54, 1·38 − 1·72) or emergency (1·21, 1·01–1·34) Caesarean sections and neonatal intensive care unit admissions (1·28, 1·09 − 1·50); and less early skin-to-skin contact (0·82, 0·73 − 0·92), breastfeeding (0·90, 0·81 − 0·99), and 3rd or 4th degree vaginal tears (0·82, 0·75 − 0·90). Conclusion More vANC, as a proportion of antenatal care received, was associated with more adverse pregnancy outcomes, when women received vANC in the second or third trimesters.