What is a Booked Pregnancy?
A booked pregnancy refers to a pregnancy in which the woman has registered for and is receiving formal antenatal care at a healthcare facility, typically initiated in the first or early second trimester. This term is primarily used in international healthcare settings, particularly in developing countries and the United Kingdom, to distinguish women who are enrolled in prenatal care systems from those who present for delivery without prior antenatal surveillance ("unbooked" patients) 1, 2.
Clinical Definition and Timing
Booking is the initial registration visit for antenatal care where comprehensive risk assessment occurs, ideally before 10 weeks gestation but commonly accepted up to 20 weeks 3, 4.
At the booking visit, baseline measurements are obtained including booking blood pressure and booking proteinuria status, which serve as critical reference points for detecting pregnancy complications like pre-eclampsia 4.
The booking appointment establishes the woman's risk profile and determines the appropriate level of antenatal surveillance needed throughout pregnancy 4.
Key Components of Booking Assessment
The booking visit involves systematic evaluation of risk factors that guide the antenatal care plan 4:
Demographic factors: Age (≥40 years carries 1.68-1.96 times increased pre-eclampsia risk), parity status, body mass index (≥35 increases risk) 4, 3
Medical history: Pre-existing hypertension, renal disease, diabetes, antiphospholipid antibodies 4
Obstetric history: Previous pre-eclampsia (7.19 times increased risk), pregnancy interval ≥10 years, multiple pregnancy 4
Baseline vital signs: Booking diastolic blood pressure ≥80 mm Hg triggers enhanced surveillance 4
Clinical Significance of Booking Status
Unbooked patients face substantially worse outcomes compared to booked patients, though the magnitude varies by healthcare setting:
In resource-limited settings, unbooked mothers experience 3 times higher neonatal mortality and 36% incidence of low birth weight babies versus 12.5% in booked patients 5.
Unbooked mothers are 13 times more likely to die during hospitalization compared to booked patients 6.
Unbooked patients have significantly higher rates of pre-eclampsia/eclampsia (OR 3.88), uterine rupture (OR 8.80), and birth asphyxia (OR 9.0) 6.
However, in well-resourced tertiary centers with universal healthcare access, perinatal and maternal mortality may be equivalent between booked and unbooked groups, suggesting that access to quality delivery care can partially mitigate the lack of antenatal surveillance 2.
Referral Criteria After Booking
Women identified at booking with high-risk features require specialist referral before 20 weeks gestation 4, 3:
- Previous pre-eclampsia
- Multiple pregnancy
- Pre-existing hypertension or booking diastolic BP ≥90 mm Hg
- Pre-existing renal disease or booking proteinuria
- Pre-existing diabetes
- Antiphospholipid antibodies
- Any two other risk factors from the standard assessment list
Common Pitfalls
Multiple concurrent bookings: Some women book at multiple facilities simultaneously, which can lead to confusion about delivery location (53.1%), default on expert advice (27.5%), and management complications 1.
Late booking: Average gestational age at booking in some settings is 19 weeks, with late booking (≥17 weeks) associated with lower maternal education and lack of knowledge about appropriate timing 7.
The term "booked" should not be confused with "viable pregnancy" - these are distinct concepts, as viability refers to fetal developmental status confirmed by ultrasound (cardiac activity visible at ≥6 weeks), not maternal enrollment in care 4.