Results
The participants were on average 29.1 (SD: 5.3) years old. The first
antenatal care visit was on average at 12.9 (SD: 3.7) weeks, and 81.4%
of the participants started antenatal care in the first 14 weeks of
pregnancy. The pregnancy was on average recognized at 5.4 (SD: 2.3)
weeks, and 81.7% of the participants recognized their pregnancy within
6 weeks. The participants who had their first antenatal visit within 14
weeks of pregnancy significantly differed in all studied predictors from
participants who had their first antenatal visit later than 14 weeks,
except for mental illness. Table 1 shows a detailed description of the
study population.
Participants who recognized their pregnancy within 6 weeks had their
first visit in antenatal care 1.25 weeks earlier (95% CI=-1.60; -0.91)
than those who recognized their pregnancy later than 6 weeks
(βadjusted=-0.63; 95% CI=-0.97; -0.28). In addition,
all predictors were significantly associated with timing of antenatal
care initiation (Table 2). The associations were most prominent for the
following predictors: participants aged <20 years were 2.95
(95% CI=2.31; 3.63) weeks later than those aged 30-35 years; first
generation migrants were 1.53 (95% CI=1.29; 1.78) weeks later than
those without migration background; those with unplanned pregnancy and
ambivalent feelings were 2.14 (95% CI=1.75; 2.54) weeks later than
those with planned pregnancy; participants without sufficient Dutch
language skills were 1.63 (95% CI= 1.25; 2.02) weeks later than those
with sufficient Dutch language skills; those who already had 3 children
or more were 1.57 (95% CI=0.90; 2.29) weeks later than nulliparous
participants; participants with lower educational attainment were 1.50
(95% CI= 1.20; 1.81) weeks later than participants with higher
educational attainment; unemployed participants were 1.60 (95% CI=1.35;
1.86) later than employed participants; those with a lower household
income were 2.05 (95% CI=1.77; 2.34) weeks later than those with a
higher household income; and those living in highly deprived
neighborhoods were 1.52 (95% CI=1.24; 1.79) weeks later than those
living in low deprived neighborhoods.
Hypothetically intervening on pregnancy recognition (≤6 weeks) reduced
the inequalities in antenatal care initiation. These reductions were
significant for age, migration background, pregnancy intention,
education, employment, household income, housing, and neighborhood
deprivation. Table 2 and Figure 1 show the inequality before and after
the intervention, and the corresponding reductions. For example, the
inequality between those aged <20 years and those aged 30-35
years was β=2.95 weeks (95% CI=2.31; 3.63) prior to the intervention,
which became β=2.55 weeks (95% CI=1.91; 3.23) after the intervention,
indicating a significant reduction of β=-0.40 (95% CI=-0.69; -0.15).
Similarly, the inequality between those with unplanned and ambivalent
pregnancy and those with planned pregnancy was β=2.14 weeks (95%
CI=1.75; 2.54) prior to the intervention, which became β=1.77 weeks
(95% CI=1.38; 2.18) after the intervention, indicating a significant
reduction of β=-0.37 (95% CI=-0.57; -0.18).
Sensitivity analyses including only participants with a regular cycle
(n=2360) are shown in Table S1. Participants who recognized their
pregnancy within 6 weeks had their first visit in antenatal care 1.14
weeks (95%CI -1.58; -0.69) earlier than those who recognized their
pregnancy after 6 weeks (βadjusted=-0.47, 95%CI -0.91;
-0.03). All predictors remained associated with timing of antenatal care
initiation. Hypothetically intervening on pregnancy recognition
significantly reduced the inequalities for pregnancy intention (planned
vs unplanned and ambivalent), migration background (no vs first
generation), and neighborhood deprivation (low vs high).