Association between antenatal care utilization, preeclampsia, and neonatal Apgar scores among postnatal women in Eswatini: an analytical cross-sectional study

Abstract

Background

Preeclampsia is a hypertensive disorder that occurs during pregnancy significantly associated with maternal morbidity and mortality worldwide. It is associated with complications for both mothers and babies although 10 – 20% may be prevented through proper antenatal care (ANC) utilization. In Eswatini, despite high ANC coverage, there has been an increase in maternal and neonatal deaths with limited evidence of the associated factors. Therefore, this study examined the utilization of ANC services, prevalence, and factors associated with pre-eclampsia and low Apgar Score among Postnatal Women in Eswatini.

Method

A hospital-based cross-sectional analytical study among 216 postnatal women was conducted in Eswatini between April and June 2024. Data were collected through face-to-face interviews using a validated questionnaire and by extracting data from hospital records. Multivariate logistic regression was used to determine the association between ANC service utilization, preeclampsia, Apgar score, and other factors (socio-demographic and obstetric characteristics). Results presenting a p-value < 0.05 were considered significant.

Results

The mean age of participants was 26.78 ± 6.7 years. All participants had attended ANC services, and over half, 20.4% (n = 44) of the women, booked early. Only about two percent (1.9%, n = 4) of postnatal women had greater than 8 ANC service utilization. Among all women, 19.0% (n = 41) were diagnosed with preeclampsia: 16.7% (n = 36) during ANC visits and 2.3% (n = 5) during postpartum care. Among neonates, 17.3% (n = 37) had a low Apgar score. The mean Apgar score among them was 8.4 ± 1.8. Adequate ANC frequency was associated with 42% lower odds of preeclampsia (AOR: 0.58, 95% CI: 0.76, 0.90) and 71% lower odds of low Apgar score (AOR: 0.29, 95% CI: 0.09, 0.55). Gestational age was another factor associated with lower odds of both pre-eclampsia and low Apgar score (AOR: 0.05, 95% CI: 0.02,0.15) and (AOR: 0.22, 95% CI: 0.08, 0.62), respectively.

Conclusion

The study highlights that adequate utilization of ANC services reduces the odds of pre-eclampsia and low Apgar scores. The findings are consistent and confirm the previous studies, but provide the first nationally relevant estimates from Eswatini, offering important insights for improving ANC quality and reducing maternal and neonatal morbidity. We recommend a community intervention in Eswatini to create awareness about the importance of ANC utilization.

Background

Hypertensive diseases are a leading cause of morbidity and mortality among mothers and fetuses globally, accounting for approximately 18% of maternal deaths [1–3] and 30% of perinatal mortality [4]. Preeclampsia is a hypertensive disorder that affects multiple organ systems and typically develops after 20 weeks of pregnancy [5]. It impacts around 2–10% of pregnant women worldwide and is a significant contributor to high maternal morbidity and mortality [6], accounting for 10–15% of direct maternal fatalities [7].

Preeclampsia is a global health concern, particularly prevalent in low-, middle-, and high-income countries, with notably high rates in Sub-Saharan Africa (56%) and South Asia (85%) [8]. Approximately 27% of neonates are significantly affected by preeclampsia, which is responsible for 30% of perinatal and neonatal deaths [4]. Research has demonstrated an association between preeclampsia and neonatal mortality [9, 10]. This condition can lead to adverse outcomes during pregnancy, such as preterm birth, cesarean section, and low Apgar scores [11]. Studies indicate that appropriate use of antenatal care (ANC) can reduce the incidence of these adverse outcomes by 10–20% [12].

Ninety-nine percent of maternal deaths occur in low-resource settings [13]. However, many of these deaths can be prevented through the recommended use of antenatal care [14]. Proper utilization of ANC provides a crucial opportunity for the early identification, prevention of diseases, health promotion, and evidence-based treatment of illnesses during pregnancy [15]. Furthermore, efficient use of ANC could potentially save the lives of three million babies in severely impoverished nations like Swaziland. Neonatal mortality rates (NMR) can be reduced by 10–20% through the provision of ANC alone [11, 16]. Preeclampsia can be prevented and its effects mitigated by addressing the medical needs of pregnant women [6]. The occurrence of preeclampsia is linked to antenatal care and is notably more common among pregnant women who do not have regular antenatal appointments compared to those who do [17]. According to Mbuagbaw et al., [18], improvements in the health system can lead to reductions in both neonatal and maternal mortality rates (NMR and MMR) alongside increased coverage of prenatal care (ANC). Kawungezi et al., [19] further supported this by stating that persistently high rates of maternal and neonatal deaths are attributed to inadequate use of ANC.

In 2016, the World Health Organization (WHO) updated its guidelines for antenatal care (ANC) to improve the health of mothers and newborns. The new recommendations increased the minimum number of focused visits from four to eight. Globally, 88% of expectant mothers received professional ANC at least once, and 66% attended at least four visits [20]. In Eswatini, 85% of women have access to ANC, and 76% attend at least 4 visits [21]. Yet the maternal mortality rate (MMR) remains high. The MMR improved from 588 per 100,000 live births in 2000 to 240 per 100,000 live births in 2020 [22]. While 64.6% of women in Eswatini had five or more ANC visits [23]. These statistics remain unacceptable, despite the country's provision of free maternal, neonatal, and child health (MNCH) services in public health facilities.

The data demonstrate that pregnant women who receive inadequate antenatal care (ANC) are more likely to give birth at home without the assistance of a skilled birth attendant [24]. Research indicates that this situation increases the chances of complications for both mothers and their infants, as well as the potential for death [25]. Additionally, increasing ANC coverage can help reduce neonatal mortality rates (NMR) and maternal mortality rates (MMR), in addition to decreasing other health-related expenses [18].

Factors affecting the uptake of antenatal care, long distance from health facility, lack of transportation, cultural norms, cost associated with healthcare, maternal education, age, and perceived inadequacies in quality of care have been studied in many research studies in other countries [26, 27]. But there is a dearth of data to explain the relationship between antenatal care utilization, preeclampsia, and low Apgar score among postnatal women and their newborns in Eswatini [28].

Although previous studies in Sub-Saharan Africa have established associations between ANC utilization and maternal/neonatal outcomes, no prior study in Eswatini has simultaneously examined preeclampsia and neonatal Apgar scores across multiple regional hospitals. This evidence gap is critical, as Eswatini reports high ANC attendance yet still experiences elevated maternal and neonatal mortality. Therefore, this study aimed to assess the ANC services utilization, the prevalence of pre-eclampsia, and neonatal Apgar score and their associated factors among postnatal women in Eswatini.

Materials and methods

Study design and setting

This study used an analytical cross-sectional study design that allowed the timely collection of data from postnatal women at the point of discharge, capturing both antenatal exposure variables and maternal/neonatal outcomes from clinical records and interviews. The study was conducted in Eswatini at four regional hospitals from April to June 2024. Eswatini, a landlocked country bordered by South Africa and Mozambique, has a fertility rate of 2.71 children per woman and a birth rate of approximately 25.5 per 1,000 people, with a notably high rate among adolescents (87/1,000). The country consists of four regions: Hhohho (320,651), Manzini (355,945), Lubombo (237,500), and Shiselweni (212,200) [29]. Eswatini has 14 hospitals (six of which are private), five health centers, six public health units, 215 clinics, and 100 private clinics. The study was conducted in four regional hospitals: Pigg’s Peak Government Hospital, Relefitkin Memorial Hospital, Good Shepherd Mission Hospital, and Hlatikhulu Government Hospital, which are known for high delivery rates. Government healthcare facilities often face shortages and understaffing. The country struggles with a rising maternal mortality rate, reported at 240 per 100,000 live births in 2020 [22, 30].

Study population and selection criteria

The study included postpartum women, aged 15 to 49 years, from the day of delivery until discharge, along with their neonates. All postpartum women and their neonates, regardless of the mode of delivery, were included in the study upon providing their consent. However, postpartum women who were ill and unable to respond during data collection, as well as those who lacked supporting information from other sources (such as ANC booklets, referral notes, or documents from parents or guardians), were excluded.

Sample size and sampling

The sample size was calculated using the Kish-Leslie formula (1965), as follows: n = Z²p(1-p)/e², which is consistent with our previous study. Where n equals the minimum required sample size, Z is the confidence level at 95% (standard value of 1.96), p is the proportion of the estimated level of knowledge, and the margin of error is 0.05. We assumed the proportion to be 85% as reported in a previous study [31].

Therefore, the minimum sample size was 196, and by accounting for a 10% non-response rate, the final sample size was 216.

Sampling

The four regional hospitals were selected for their representative nature, as each represents a distinct region, and no study was conducted simultaneously in all four. The maternity unit was purposefully chosen for the postnatal ward. The total sample size per facility was calculated using proportionate stratified sampling, with the annual total number of deliveries across all facilities serving as the denominator and the total deliveries for each facility as the numerator, multiplied by the total sample size of the study. Based on the formula below, n represents the annual total deliveries at the selected facility, N represents the yearly total deliveries for the four hospitals, Ni represents the total sample size, and n represents the sample size from each facility. Ni = (n/N) Ni. Number of the postnatal women recruited in each hospital: Pigg’s Peak Government Hospital = 45, Relefitkin Memorial Hospital = 69, Good Shepard Mission Hospital = 56, and Hlatikulu Government Hospital = 46. Systematic random sampling was used to select participants in the ward. We developed a sampling frame from the delivery register, which records the total number of postnatal women per day. The first participant was randomly selected, and the next were chosen using the Kth interval, which was 3, in the regional government hospitals (Hlatikhulu and Pigg’s Peak). The first participant was randomly selected, and the next participant was chosen using the k^th interval. The following day, if the postnatal women had not been discharged, they would be included in the sampling frame, and those who had participated the previous day would be excluded. The same procedure was done in all health facilities included in the study.

Data collection methods and tools

Two methods of data collection were used. A validated, structured, interviewer-administered questionnaire and a documentary review were used for data collection. The validated questionnaire was adapted from a previous study [9] and modified and customized to the Swazi culture, including translation into the Siswati language. A bilingual person fluent in English and Siswati translated the questionnaire into Siswati. To ensure the validity of the questionnaire, an item analysis was conducted, and the Cronbach’s alpha coefficient of 0.755 indicated that the items correlated well with one another. The questionnaire was pretested among 22 postnatal women in different hospitals (Mankayane). Some questions were revised to clarify ambiguous items (maternal weight and height, the test done at ANC change, gestation at test, and response options changed from 'yes', 'no', or 'known status'). The modified questionnaire was validated to assess its internal consistency, yielding a value of 0.705, indicating that the questionnaire is reliable.

The questionnaire consisted of four sections: socio-demographic characteristics, past obstetric history, antenatal history for the current delivery, and intrapartum and postnatal findings. Data were collected by the principal investigator and one research assistant (a registered nurse midwife), who were oriented to the questionnaire the day before the pretest. For postnatal women who met the inclusion criteria, consent was obtained verbally. Participants were then taken to a private room for the interview, where they first signed a written permission form. The interview took approximately 20 to 30 min per participant. The completed questionnaire was locked in a briefcase for safety and confidentiality.

Variable and variable measurement

Sociodemographic characteristics, including maternal age, parity, and frequency of ANC visits, were measured using an interval scale, and employment history, educational level, marital status, smoking and alcohol consumption history, gestational age at ANC visit initiation, birth interval, and history of hypertension were measured using a nominal scale, and BMI was measured using an ordinal scale, measure using WHO classification: < 18.50 (underweight), 18.50–24.99 (normal), 25.00–29.99 (overweight), and ≥ 30.00 (obesity).

Adequacy of antenatal care utilization was defined as a composite variable that encompasses the timing of ANC booking, frequency of ANC attendance, and the contents of ANC services received. Each of these dimensions independently influences maternal and neonatal outcomes. By integrating them, we obtain a more valid and comprehensive indicator of ANC coverage than any single element could provide on its own. It was categorized into three tiers as (i) Adequate ANC utilization (Tier 1) when a woman had (a) early booking at ≤ 12 weeks, (b) attended ≥ 8 visits, and (c) received at least 80% of all recommended services. (ii) Moderately adequate (tier 2/desired), when a woman had (a) early booking at ≤ 12 weeks, (b) attended ≥ 4 visits, and (c) received at least 80% of all recommended services; and (iii) Inadequate (tier 3) when a woman had (a) late booking at > 12 weeks or, (b) attended < 4 visits, and/or (c) received < 80% of all recommended services. This operationalization integrates both quantity and quality dimensions, which provides a more rigorous measure than commonly used single indicators.

ANC service utilization was assessed by reviewing the postnatal women’s hospital files and the ANC cards. The frequency of the ANC visit was assessed from the ANC card using a ratio scale. The number of ANC visits was categorized into two categories: 8 or more ANC visits and fewer than 8 ANC visits [32]. This was measured using an ordinal scale, and the services received at ANC were assessed using ANC cards.

ANC booking was categorized into two groups: early and late. Women who scheduled their antenatal care (ANC) appointments during their first trimester (≤ 12 weeks of pregnancy) were classified as 0 (early booking), while those who booked appointments during the second or third trimester, attending after 12 weeks of pregnancy, were classified as 1 (late booking) [33].

Antenatal Care Coverage focuses on whether women access ANC at all (includes booking and subsequent visits).

Preeclampsia and/or severe preeclampsia were assessed using six questions that were dichotomized into positive responses (yes = 1) and negative responses (no = 0). Postnatal women were asked about their history of preeclampsia using questions regarding severe features, including gestational hypertension with a severe range of systolic blood pressure > 160 mmHg and diastolic > 110 mmHg, protein in urine (proteinuria), swelling of the face and extremities or generalized edema, blurred vision, severe headache, and severe persistent right upper quadrant or epigastric pain unresponsive to medication, which was not accounted for by an alternative diagnosis. To confirm the diagnosis, we reviewed the ANC card and the participant's hospital file from admission to discharge. On the ANC card, we looked for those with protein in urinalysis and elevated blood pressure above 140/90 mmHg. The hospital file included a list of maternal outcome conditions, where preeclampsia is among the options. Some women were diagnosed during the intrapartum period, and postnatal assessments were conducted on maternal outcomes, measured using an interval scale.

Neonatal apgar score

As suggested in previous studies, birth asphyxia was defined as a neonatal Apgar score of less than 7 at five minutes or a baby not crying immediately after birth. It was measured using Apgar score at 5 min, categorized into normal (≥ 7) and low (< 7), similar to our previous study [9].

Data analysis

Data entry for this study was conducted using SPSS version 25, with initial procedures focused on cleaning and verifying the data for completeness and accuracy to eliminate any errors and inconsistencies. Following this, multivariable logistic regression was carried out to estimate adjusted odds ratios (AORs) and assess the association between antenatal care (ANC) service utilization, socio-demographic characteristics, preeclampsia, and Apgar scores. Model parameters were derived through maximum likelihood estimation, and 95% confidence intervals were computed based on the standard errors of the regression coefficients. Variables were included in the model if they showed significance at p < 0.05 in bivariate analysis or were deemed clinically relevant. A p-value of less than 0.05 was considered statistically significant. Additionally, multicollinearity among potentially interrelated variables (gestational age, birth weight, and frequency of ANC visits) was evaluated, with a variance inflation factor (VIF) of 5 or less deemed acceptable.

Results

Socio-demographic characteristics

This study included 216 postnatal women of childbearing age, and the response rate was 100%. The mean age of participants was 26.78 ± 6.7 years. The majority, 73.2% (n = 158), of women were aged 26–35 years. Most, 61.2% (n = 133) of the women attained a high school education, and more than half, 61.1% (n = 132) were employed.

As for obstetric characteristics, more than half, 55.1% (n = 119), were multipara with 2–4 deliveries, and the mean parity was 2,63 ± 1.6 deliveries. Almost half, 48.61% (n = 105), of the women had a birth interval of 2–6 years, and less than a quarter, 17.13% (n = 37), had a birth interval of more than 6 years. 38.9% (n = 84) of the women were overweight. In terms of gestational age at delivery, the majority, 75.0% (n = 162) of women delivered at term (38–42 weeks).

Concerning ANC booking and Frequency of ANC visits, all postnatal women attended at least one ANC visit. The mean number of ANC visits attended was 4.27 ± 1.7 visits. The number of visits varied, ranging from 1 to 10. The majority of participants, 98.1% (n = 212), attended fewer than eight ANC visits. As for the timing of their ANC visits, less than a quarter of the participants, 20.4% (n = 44), booked their first ANC visit at the first trimester (0–12 weeks of gestation), whereas 66.7% (n = 144) attended during the second trimester (13–26 weeks), and 13% (n = 28) attended during the third trimester (Table 1).

Table 1.

Socio-demographic and obstetric characteristics of postnatal women participating in the study (N = 216)

Variable	Frequency (n)	Percentage (%)	Mean ± SD
Age (years)			26.78 ± 6.7
15–25	32	14.8
26–35	158	73.2
36–49	26	12.0
Employment history
Employed	53	24.5
Self-employed	79	36.6
Unemployed	84	38.9
Alcohol consumption
Yes	7	3.2
No	209	96.8
Marital status
Married	76	35.2
Single	140	64.8
Educational level
Primary	48	22.5
High school	133	61.6
Tertiary	35	16.2
Parity			2.63 ± 1.6
Primipara	65	30.1
Multipara	119	55.1
Grand multipara	32	14.8
Birth interval (years)			3.37 ± 3.1
< 2	74	34.3
2–6	105	48.6
> 6	37	17.1
GA at delivery (weeks)			37.486 ± 3.1
28–34	33	15.3
35–37	21	9.7
38–42	162	75
BMI (Kg/M2			28.27 ± 5.1
< 18.50	12	5.6
18.5–24.99	48	22.2
25.00–29.99	72	33.3
≥ 30	84	38.9
Chronic hypertension
Yes	9	4.2
No	207	95.8
Mode of delivery
SVD	181	83.8
AVD	8	3.2
CS	27	12.5
ANC Booking (weeks)			18.81 ± 6.8
≤ 12	44	20.4
> 12	172	79.6
Frequency of ANC visits			4.27 ± 1.7
< 8	212	98.1
≥ 8	4	1.9

GA Gestation age, BMI Body Mass Index, SVD Spontaneous vaginal delivery, AVD Assisted vaginal delivery, CS Cesarean section delivery, and ANC Antenatal care

Neonatal characteristics

Among the neonates involved in the study, along with their mothers (N = 216), more than half, 53.7% (n = 116), were born with a normal birth weight (2.5–3.9 kg), and less than a quarter, 22.2% (n = 48), had macrosomia. The mean birth weight was 2.85 ± 0.8 kg. A majority (82.9%; n = 179) of neonates had Apgar scores of 7 or higher at 5 min. (Table 2 summarizes the characteristics of neonates included in the study).

Table 2.

Neonatal characteristics (N = 216)

Variable	Frequency (n)	Percentage (%)	Mean ± SD
Birth weight (kgs)			2.85 ± 0.8
< 2.5 kg	52	24.1
2.5–3.9 kg	116	53.7
≥ 4 kg	48	22.2
Apgar score (at 5 min)			8.40 ± 1.8
Normal Apgar score	179	82.9
Birth asphyxia (Low Apgar score)	37	17.1

Antenatal care services utilization

ANC service utilization was captured as a composite variable comprising three domains, including ANC booking, frequency of ANC attendance, and diagnostic, preventive/curative, and promotive services received by women. The majority of women (79.6%, n = 172) booked ANC after the first trimester, contrary to WHO recommendations, with 13% (n = 28) booking in the third trimester. The mean gestational age at ANC booking was 18.81 weeks (SD = 6.8). Women attended a mean of 4.27 ± 1.7 ANC visits, with one visit the fewest and ten the most. Only four women (≈ 2%) attended eight or more ANC visits, and the majority (70.8%) attended between 4 and 7 visits. During ANC visits, all women received diagnostic, preventive/curative, and promotive services in line with WHO recommendations. Every woman (100%) received HIV testing, counseling, blood pressure measurement, and weight monitoring during ANC. The least offered services were malaria testing (60.2%, n = 130) and prescriptions for albendazole (55.6%, n = 120). Table 3 summarizes ANC utilization among women, including ANC booking, frequency of ANC attendance, and key ANC services received.

Table 3.

Antenatal (ANC) utilization by the women (N = 216)

Variable	Frequency (n)	Percentage (%)
GA at ANC booking
1–12 weeks (1st Trimester)	44	20.4
13–26 weeks (2nd Trimester)	144	66.7
> 27 weeks (3rd Trimester)	28	13.0
Frequency of ANC visits
0–4 visits	120	55.6
5–7 visits	92	42.6
≥ 8 visits	4	1.9
ANC services received
HIV testing	216	100
HepBSAg	183	84.7
Malaria	130	60.2
VDRL	186	86.1
Blood group	131	60.7
Urinalysis	198	91.7
Tetanus vaccine	194	89.8
Folic Acid supplementation	190	88
Ferrous sulphate supplementation	190	88
Albendazole administration	120	55.6
Nutrition counselling	197	91.2
Counselling on danger signs	197	91
Blood pressure	216	100
Weight taken	216	100

Adequacy of ANC utilization

As a composite variable of ANC utilization, those who met all the WHO recommendations, that is, they made early ANC booking at ≤ 12 weeks, attended ≥ 8 visits, and received at least 80% of all recommended ANC services considered as “adequate ANC utilization/tier 1” were only one percent (n = 2); whereas those with “moderately adequate ANC utilization” who at least made early booking at ≤ 12 weeks, attended ≥ 4 visits, and received at least 80% of all recommended services were also very few (9.3%, n = 20). The majority (89.8%, n = 194) were those who did not follow the WHO’s recommendation, considered to have “inadequate ANC utilization” as they had been late booked at > 12 weeks or attended < 4 visits, and/or received < 80% of all recommended services. Figure 1 illustrates the proportion of women according to the adequacy of ANC utilization.

Fig. 1.

Proportion of women according to the adequacy of ANC utilization

Prevalence of pre-eclampsia among postnatal women (N = 216)

Postnatal women could be diagnosed with preeclampsia during the ANC, intrapartum, and postpartum periods. In this study, less than a quarter, 16.7% (n = 36) of postnatal women were diagnosed with preeclampsia during ANC visits, and 2.3% (n = 5) of them were diagnosed with preeclampsia during postpartum care, which makes the total prevalence of preeclampsia to be 19.0% (n = 41) (Fig. 2).

Fig. 2.

Prevalence of Pre-eclampsia among postnatal women (N = 216)

ANC service utilization, sociodemographic and obstetric characteristics, as determinants of Apgar score

After adjusting for potential confounding factors using multivariate analysis, gestational age, birth weight, BMI, frequency, and booking were significantly associated with Apgar score. Gestational age and birth weight were factors negatively associated with a low Apgar score: women with gestational ages of 35–37 and 38–40 weeks had 88% and 93% lower odds, respectively, of having newborns with a low Apgar score, compared to women with gestational ages of 28–34 weeks: (AOR: 0.22, 95% CI: 0.08–0.62, p = 0.004) and (AOR: 0.07, 95% CI: 0.03–0.20, p = 0.001). Postpartum women with a BMI greater than 30 during pregnancy were 1.8 times more likely to deliver a newborn with a low APGAR score than women with a normal BMI (AOR = 1.8, 95% CI: 1.35–2.44, p = 0.001). Postpartum women who started ANC booking after 12 weeks of pregnancy face a higher odds of having newborns with low APGAR scores (AOR = 1.22, 95% CI: 3.12–6.51, p = 0.001). Postpartum women who attended at least eight ANC visits during pregnancy had a protective effect against low Apgar scores, with an odds ratio of 0.29 compared to those with fewer visits (AOR: 0.29, 95% CI: 0.09–0.55, p = 0.001). Nevertheless, the composite variable ANC adequacy was not associated with the odds of low Apgar score (Table 4).

Table 4.

Logistic regression for the association between ANC service utilization, sociodemographic, and obstetric factors with Apgar score (N = 216)

Variable	COR (95% CI)	P-value	AOR (95% CI)	P-value
Marital status
Single	Ref
Married	1.73 (0.84,3.54)	0.135	2.04 (0.86,4.75)	0.098
GA at delivery (week)
28–34	Ref
35–37	0.22 (0.08,0.06)	0.002	0.22 (0.08,0.62)	0.004
38–40	0.08 (0.03,0.20)	< 0.001	0.07 (0.03,0.20)	< 0.001
BMI (kg/M2)
18.5–24.99	Ref
< 18.50	0.35 (0.13,0.95)	0.038	0.08 (0.01,1.10)	0.296
25.00–29.99	1.77 (1.74,2.56)	0.533	0.12 (0.01,1.61)	0.109
≥ 30	1.4 (1.22–1.81)	0.001	1.8 (1.35,2.44)	0.001
Birth weight
Low	Ref
Normal	0.14 (0.06,0.32)	0.001	0.15 (0.06,0.33)	0.001
Macrosomia	0.87 (0.19,3.81)	0.853	0.73 (0.16,3.37)	0.694
ANC booking (weeks)
≤ 12 (Early)	Ref
> 12 (late)	1.64 (1.99,4.12)	< 0.001	1.22 (3.12,6.51)	< 0.001
ANC frequency covered
< 8 visits (Inadequate)	Ref
≥ 8 visits (Adequate)	0.40 (0.15,0.82)	0.001	0.29 (0.09,0.55)	0.001
ANC service utilization
Adequate (Tier 1)	36E8 (0.00, ∞)	0.999	79E8 (0.00, ∞)	0.999
Moderately adequate (Tier 2/desired)	1.20 (0.46, 3.17)	0.709	1.50 (0.52,4.33)	0.452
Inadequate (Tier 3)	Ref		Ref

GA Gestation age, BMI Body Mass Index, ANC Antenatal care

ANC services utilization with pre-eclampsia and controlled for sociodemographic and obstetric characteristics

After adjusting for all factors, maternal age, birth interval, gestational age at delivery, body mass index, educational level, birth weight, history of hypertension, frequency, and booking were statistically significantly associated with preeclampsia. Postnatal women aged 26–35 years had 86% lower odds of developing pre-eclampsia compared to postnatal women aged 15–25 years (AOR: 0.24, 95% CI: 0.06–0.97, p < 0.046). The odds of pre-eclampsia was 4.36 times higher among postnatal women with birth intervals longer than 6 years compared to those with birth intervals of less than or equal to 2 years (AOR: 4.36, 95% CI: 1.24–15.39, p < 0.022). Women with a gestational age at delivery of 38 to 42 weeks had 95% reduced odds of pre-eclampsia compared to those with a gestational age of 28 to 34 weeks (AOR: 0.05, 95% CI: 0.02–0.15). Postnatal women who had a BMI ≥ 30 during pregnancy had significantly higher odds of developing pre-eclampsia than their counterparts with normal BMI (AOR = 3.72, 95% CI: 1.41–9.80, p = 0.008). Women who gave birth to babies with normal birth weights had a more protective effect against developing pre-eclampsia than women who gave birth to low-birth-weight neonates (AOR: 0.19, 95% CI: 0.08–0.45, p < 0.001). Postnatal women with a history of hypertension were 3.06 times more likely to develop pre-eclampsia than those without such a history (AOR: 3.06, 95% CI: 1.94–4.23). Women who booked early for ANC had 85% reduced odds of pre-eclampsia (AOR: 0.15, 95% CI: 0.06–0.33). Those who had ANC utilization for at least 8 visits or more had a 42% lower chance of developing pre-eclampsia compared to women with fewer visits. Nevertheless, the composite variable ANC adequacy did not show any association with the odds of pre-eclampsia (Table 5).

Table 5.

Binary logistic regression on Antenatal Care Utilization with pre-eclampsia and controlled for sociodemographic and obstetric characteristics (N = 216)

Variable	COR (95% CI)	P-value	AOR (95% CI)	P-value
Maternal age (years)
15–25	Ref
26–35	0.93 (0.43,1.97)	0.849	0.24 (0.06,0.97)	0.046
36–49	1.93 (0.73,5.05)	0.182	0.31 (0.05,1,88)	0.203
Marital status
Single	Ref
Married	1.79 (0.89,3.57)	0.099	1.43 (0.57,1.88)	0.203
Birth interval (years)
≤ 2	Ref
3–6	1.69 (0.76,3.78)	0.194	2.14 (0.69,6.54)	0.183
> 6	3.21 (1.30,7.92)	0.011	4.36 (1.24,15.39)	0.022
GA at delivery (weeks)
28–34	Ref
35–37	0.50 (0.21,1.23)	0.13	0.46 (0.16,1.30)	0.142
38–42	0.06 (0.03,0.19)	0.001	0.05 (0.02,0.15)	0.001
BMI (kg/m2)
18.5–24.9	Ref
< 18.5	0.45 (0.15,1.33)	0.151	0.68 (0.22,2.18	0.524
25–29.9	2.21 (1.97–2.49)	0.002	3.66 (3.04–4.43)	0.001
≥ 30	2.12 (1.93,4.83)	0.045	3.72 (1.41,9.80)	0.008
Education level
Primary	Ref
High school/Tertiary	0.32 (0.15,0.70)	0.004	0.29 (0.12,0.67)	0.004
Birth weight
Low (< 2.5 kg)	Ref
Normal	0.30 (0.15,0.62)	0.001	0.19 (0.08,0.45)	0.001
Macrosomia	0.25 (0.03,2.13)	0.205	0.09 (0.09,0.94)	0.543
History of hypertension
No	Ref
Yes	2.82 (2.34,4.12)	0.002	3.06 (1.94,4.23)	0.005
ANC booking
Late (> 12 weeks)	Ref
Early (< 12 weeks)	0.14 (0.06,0.32)	0.001	0.15 (0.06,0.33)	0.001
ANC frequency
Inadequate (< 8 visits)	Ref
Adequate (≥ 8 visits)	0.69 (0.77,0.81)	0.001	0.58 (0.76,0.90)	0.004
ANC service utilization
Adequate (Tier 1)	0.00 (0.00, ∞)	0.999	0.00 (0.00, ∞)	0.999
Moderately adequate (Tier 2/desired)	1.95 (0.69,5.42)	0.202	2.02 (0.68, 6.30)	0.204
Inadequate (Tier 3)	Ref		Ref

Discussion

This study examined ANC services utilization, the prevalence of pre-eclampsia, and neonatal Apgar score and their associated factors among postnatal women in Eswatini. This study demonstrated that ANC utilization, particularly timely initiation and adequate visit frequency, was associated with maternal and neonatal outcomes. In addition, maternal age, birth interval, gestational age, BMI, educational level, birth weight, and chronic hypertension independently predicted preeclampsia, while gestational age, BMI, birth weight, ANC timing, and ANC visit frequency predicted neonatal Apgar score.

The prevalence of pre-eclampsia in the current study was 18.98%, which is lower than the prevalence rates of 26.3%, 65.3%, and 27% reported in studies conducted in Zanzibar and the US, respectively [9, 34]. The observed differences may be attributed to the methodological differences. For instance, in the US study, the researchers included pregnant women who had known risk factors for pre-eclampsia. The study participants' characteristics might be the reason for the prevalence of pre-eclampsia.

The prevalence of pre-eclampsia found in this study was higher compared to the prevalence of 8.4%, 2.9%, 2.3%, 4.2%, 5.5% and 12% among pregnant women, which was reported in Dessie referral hospital [35], Northeast Ethiopia, Sweden [36], KCMC Tanzania [37], Addis Ababa, Ethiopia [17], and South Africa [38], respectively. The differences in prevalence rates across the various studies may be attributed to variations in methodology. In the current study, we included all postnatal women, regardless of the mode of delivery, and asked them questions regarding pre-eclampsia. We also reviewed their ANC cards and labor, delivery, and postnatal files. In contrast, other studies relied solely on information from ANC, which may have led to the omission of women who developed pre-eclampsia during labor, delivery, or the postnatal period.

The results of the current study demonstrated that a strong association between women's sociodemographic factors, obstetric variables, ANC visits, and ANC booking were associated with the occurrence of pre-eclampsia. The variables that showed a significant association with pre-eclampsia included frequency, booking, maternal age, birth interval, gestational age at delivery, body mass index, birth weight, educational level, and a history of hypertension in women.

In the current study, postnatal women who utilized adequate ANC visits were significantly less likely to develop pre-eclampsia. These findings are consistent with reports from Ethiopia [17], Tanzania [39], Uganda [40], and South Africa [41]. The probable reason for these findings may be that early detection of pre-eclampsia through effective screening of potential factors, regular clinical monitoring, biochemical tests, and the provision of aspirin and calcium supplementation can prevent a woman from developing severe pre-eclampsia and eclampsia, thereby improving the quality of life for both mother and fetus.

The composite ANC utilization variable did not exhibit a significant correlation with preeclampsia or low Apgar scores. However, early ANC booking and attendance of a minimum of 8 ANC visits were independently associated with reduced odds of both preeclampsia and low Apgar scores. A possible explanation is that the composite indicator required women to meet all three criteria simultaneously (i.e., book early, maintain a sufficient visit frequency, and receive at least 80% of the recommended services). Consequently, only 0.9% of women were recognized as adequately utilizing services. The composite measure's power to detect significant correlations was significantly diminished by the considerable imbalance, despite the individual components demonstrating significant impacts.

Regarding maternal age, findings indicated that mothers in the mid-age group (26–35 years) were less likely to develop pre-eclampsia compared to women in the advanced age. This aligns with previous studies, which found that the odds of pre-eclampsia increase significantly after the age of 35 years [6, 7, 35]. The reason for this is that as women's age increases, their ability for hemodynamic adaptation during pregnancy becomes more challenging, potentially leading to long-term cardiovascular and metabolic issues.

Conversely, some studies contradict these findings by indicating that young women aged 15–24 are at a higher odds of severe pre-eclampsia [8, 42–44]. This discrepancy may be due to a methodological difference,the participants in the previous study were primarily primigravid, which can occur among women with new sexual partners. The findings also support the observation that the majority of women with pre-eclampsia were younger than 24 years. Nulliparous women, particularly adolescents, appear to be at greater odds of pre-eclampsia compared to older women [45, 46]. However, due to fewer comorbidities, younger women may have some level of protection against pre-eclampsia compared to their older counterparts [46].

Educational level was significantly associated with pre-eclampsia. Women with higher educational levels were less likely to develop pre-eclampsia than those with lower educational levels. This finding is consistent with other studies conducted elsewhere, such as a study conducted in Pakistan [42], Sweden [47], Ghana [48], and Ethiopia [49]. Additionally, women with higher educational levels are more likely to seek healthcare services. As a result, pregnant women who are better educated tend to attend ANC appointments more regularly, which increases their chances of early identification, treatment, or referral for pre-eclampsia. It is noted that women with education are empowered to demand services and make decisions.

In this study, gestational age at delivery is significantly associated with pre-eclampsia, where women who had a term delivery were less likely to have pre-eclampsia. Similarly, several studies conducted elsewhere reported similar findings, for example, a study conducted at Missouri, the University of Cincinnati Medical Center, [50], Norway [51], Pakistan [42], and Ghana [52]. And babies born to mothers with pre-eclampsia are delivered prematurely at less than 37 weeks of gestation. This is due to the early onset of pre-eclampsia [6]. These could be an iatrogenic effect to save pregnant women with severe pre-eclampsia, as expediting the delivery of the placenta is the only treatment.

Furthermore, women with a high BMI of 35 + (obese) were associated with a higher odds of pre-eclampsia compared to women with a normal BMI of 18.5–24.5. This is supported by studies from various regions, including a systematic meta-analysis conducted in sub-Saharan Africa [53]. Similar results were reported elsewhere, such as studies conducted in Tanzania, China, Sweden, Ghana, and the USA [6, 36, 37, 54], respectively. The plausible explanation for the increased odds of pre-eclampsia with increased body weight (BMI) could be due to placental vasculopathy and endothelial dysfunction, which is the primary pathogenesis of pre-eclampsia [55, 56]. Obesity also causes hypertriglyceridemia, which leads to endothelial dysfunction and pre-eclampsia [55]. Hyperlipidemia may also alter the regulation of prostaglandins, leading to arteriolar constriction, which is primarily important as a marker for high blood pressure [56]. High blood pressure increases vascular constriction and reduces perfusion to many organs, including the placenta. Increased BMI is a major component associated with pre-eclampsia.

A previous history of hypertension among postnatal women was associated with pre-eclampsia. This finding corroborates findings from; [45, 57]. This may reflect elevated vascular resistance and reduced placental perfusion brought on by hypertension exacerbate pre-eclampsia.

Regarding birth interval, in the current study, pregnant women with a birth interval of six years or above were more likely to develop pre-eclampsia. This is in line with subsequent research, which found that an interpregnancy interval was associated with a higher odds of pre-eclampsia [58–60]. A long birth interval is often accompanied by changes in partner and advanced maternal age, which increase the risk of pre-eclampsia. Overall, both short and long birth intervals are associated with adverse pregnancy outcomes, thus emphasizing the importance of optimal birth spacing [61, 62]. Thus, antenatal care utilization significantly impacts outcomes of pregnancy complicated by pre-eclampsia.

A low Apgar score was significantly associated with gestation age, BMI, birth weight, ANC booking, and ANC frequency. Preterm birth is a particularly important predictor of a low five-minute Apgar score because physiological immaturity may compromise neonatal respiratory effort, muscle tone, reflex responses, and cardiovascular adaptation after delivery [63]. A study conducted among women with gestational diabetes in Fiji similarly found that preterm delivery and late antenatal care booking were significantly associated with a low five-minute Apgar score [64]. Studies from other settings have also identified low birth weight, inadequate antenatal care, pregnancy-induced hypertension, prolonged labour, malpresentation, and obstetric complications as predictors of low Apgar scores [65, 66]. The probable reason for the normal Apgar score associated with advanced gestational age may be the newborn's maturity. At this stage, all major organ systems, particularly the lungs and the nervous system, are fully developed, resulting in strong muscle tone, a robust heart rate, and effective reflexes.

The current study highlights the significant association between a BMI ≥ 30 and a low Apgar score. This finding is supported by a large population-based cohort study from Sweden, which demonstrated progressively increasing risks of low Apgar scores and other birth-asphyxia-related complications with increasing maternal BMI [67]. The plausible explanation for the increased odds of a low Apgar score with increased maternal body weight (BMI) could be due to difficulty in labor, which may result in fetal oxygen deprivation and an increased rate of fetal acidosis during uterine contractions and delivery. Another probable reason may be that maternal obesity or increased BMI is correlated to increased birth weight (fetal Macrosomia) above normal, which is associated with difficult delivery and leads to birth asphyxia and a low Apgar score [67, 68].

Regarding adequate ANC booking and inadequate visits, the current study found that late ANC booking is associated with an increased risk of a low Apgar score. This is supported by various studies elsewhere, such as a studies conducted in Ethiopia [65, 69] and from Fiji [64]. Pregnant women delaying the first ANC booking and inadequate visits are at a high risk of missing important early-stage care for detecting pregnancy-induced chronic conditions such as hypertension, preeclampsia, and diabetes, which compounds with neonatal complications, including placental insufficiency leading to fetal distress and low Apgar score.

Strength

Since each regional hospital was located in one of the four regions, the quantitative nature of the study and its setting enabled the findings to be applied to all women in Eswatini. This study provided the prevalence of preeclampsia among postnatal women and the Apgar score among newborns in Eswatini. The study was able to examine the relationship between multiple variables: social demographic and obstetric characteristics, ANC service utilization, preeclampsia, and Apgar score outcomes.

Limitations

This study is cross-sectional in nature, which means that the results cannot be used to establish causation. In this research, postnatal women shared their experiences related to the utilization of healthcare services and the signs of pre-eclampsia. This self-reporting may have introduced recall bias, leading to potential overreporting or underreporting, depending on individual differences in memory recall. To address the subjectivity of patient-reported information, we supplemented these findings by correlating them with the patients' antenatal care (ANC) cards and medical records. Another limitation is the lack of adjustment for comorbidities, as well as the absence of external validation through additional databases. Future research should focus on replicating and validating these findings in larger, multi-center, or international populations to enhance their generalizability. Additionally, more studies are needed to adopt qualitative and longitudinal approaches to investigate the factors influencing ANC service utilization, pre-eclampsia, and Apgar scores among postnatal women and their neonates.

Conclusion

The study found that many pregnant women had low attendance and late bookings for antenatal care (ANC), highlighting a significant gap in service utilization. This hinders the timely identification and treatment of conditions like preeclampsia. Improving ANC is crucial, as it is associated with reduced odds of preeclampsia and better neonatal outcomes, including higher Apgar scores. Policymakers should focus on increasing ANC coverage by promoting timely appointments and comprehensive services. There’s a pressing need to raise community awareness regarding the importance of early ANC booking and regular visits, as well as to enhance service delivery and resource availability for quality maternal care. Addressing these issues will lead to better maternal and neonatal health outcomes.

Author’s contributions

1. BNN made a substantial contribution to the conceptualization, methodology, design, analysis, and interpretation of data and drafted the manuscript. 2. AAJ made a substantial contribution to the concept or designed the study, data acquisition, analysis, and interpretation of data and drafted the manuscript. 3. GM made a substantial contribution to the conceptualization, conducted an in-depth literature search and participated in the study design and writing of the first draft of the manuscript. All authors reviewed the final version of the manuscript, and they agree to be accountable for the intellectual contents of the paper.

Funding

Not applicable.

Data availability

Data are available upon special request from the corresponding author.

Declarations

Ethics approval and consent to participate

Ethical clearance was obtained from the Institutional Review Committee (IRRC) at the University of Dodoma in January 2024, under reference number MA.84/261/69/6. Furthermore, ethical approval was granted by the Eswatini Health and Human Research Review Board, with reference number EHHRRB 035/2024. This research adhered to the ethical principles outlined in the Declaration of Helsinki by the World Medical Association, as documented in 2001. Before beginning data collection, participants were informed about the study’s objectives, potential risks and benefits, research procedures, and their roles in the study. They were made aware that participation was entirely voluntary and that they had the right to withdraw at any point without affecting their entitlement to receive care. Participants were asked to sign a written consent form to indicate their agreement to participate in the study. In Eswatini, the legal age for consent is 18 years; for those under this age, permission was obtained from an accompanying guardian at the hospital. Interviews were conducted in a private room to ensure confidentiality. The questionnaires were coded to safeguard participants' identities, and completed questionnaires were securely stored in a locked briefcase.

Consent for publication

Written informed consent for publication was obtained from all participants or their legal guardians.

Competing interests

The authors declare no competing interests.