The unbooked mother: a cohort study of maternal and foetal outcomes in a North London Hospital.

Objective: The aim of the study was to determine the pregnancy outcome of unbooked compared to booked women of similar parity and ethnic background over a period of 18 months at the North Middlesex University Hospital (NMUH), London.

Methods: A retrospective cohort study from September 2006 to March 2008 comparing the socio-demographics, foetal and maternal outcomes of pregnancies of unbooked versus booked women. Women who received no antenatal care or who delivered within 3 days of the initial booking visit were categorized as 'unbooked' while the next delivered women on the labour ward register (matched for ethnicity and parity) who booked prior to the second trimester served as comparison. Fischer's exact test (two-tailed), student's t test and Pearson's chi-square test, odds ratio and 95% confidence interval were used to compare the two groups statistically.

Results: There were 91 unbooked births in the 18 month study period. Unbooked mothers were younger (26.0 +/- 6.68 vs. 29.2 +/- 6.10 years, p < 0.0001), more likely to be unemployed, unmarried and non-English speaking compared to matched booked mothers (all p < 0.01). The rate of Caesarean sections ([OR] = 0.85, 95% [CI] = 0.39-1.88), p > 0.05), birth asphyxia, Apgar scores <7 at 1 min ([OR] = 1.10, 95% [CI] = 0.52-2.35, p = 0.80) and intrauterine foetal death (stillbirth) ([OR] = 2.03, 95% [CI] = 0.28-14.60, p = 0.60) were comparable between the two groups. However, unbooked mothers were five times more likely to have preterm delivery ([OR] = 6.44, 95% [CI] = 2.24-18.50, p < 0.0002); three times more likely to have low birth weight babies (<2,500 g) ([OR] = 2.87, 95% [CI] = 1.21-6.82, p < 0.02) and twice as likely to have postpartum haemorrhage ([OR] = 1.85, 95% [CI] = 0.69-4.98, p = 0.3).

Conclusion: Unbooked women were more at risk of adverse foetal and maternal outcomes than booked women, even within a population of young, relatively healthy immigrant women.