J Gandhara Med Dent Sci

ORIGINAL ARTICLE

MATERNAL RISK FACTORS FOR MODERATE AND LATE PRETERM LABOUR:

A CASE-CONTROL STUDY FROM A TERTIARY CARE HOSPITAL IN PESHAWAR

Sara Jamil

, Fauzia Afridi

, Wajeeha Javid

ABSTRACT

OBJECTIVES

The aim of the study was to determine the maternal risk factors associated

with moderate and late preterm labor.

METHODOLOGY

This case-control study was conducted at the Department of Obstetrics and

Gynaecology, Khyber Teaching Hospital, from March 1 2024, to Augus t 31

2024. Patients in the age range 18 to 40 years diagnosed with moderate and

late preterm labor were compared with controls for maternal risk factors,

including inadequate prenatal care and maternal hypertension. Data analysis

was conducted in SPSS v.26, and odds ratios were calculated using a 2x2

table.

RESULTS

The mean age of the cases was 29.14±6.239 years compared to 27.91±6.754

years in controls. The mean gestational age in cases and controls was

33.88±1.372 weeks and 38.78±1.439 weeks, respectively. Sixty-four patients

(55.7%) in cases were aged more than 30 years compared to 51 patients

(44.3%) among controls (p value 0.112). Among cases, 112 patients (49.1%)

were multiparous, versus 116 (50.9%) among controls (p value 0.901).

Overall, inadequate prenatal care was recorded in 85 participants (53;

62.4%) as cases versus 32 controls (37.6%), p value 0.006, OR 2.070 (95%

CI 1.226 - 3.497). Maternal hypertension was recorded in 74 patients, more

frequently among cases (n = 45, 60.8%) than among controls (n = 29,

39.2%), p value 0.029; OR 1.822 (95% CI 1.058 - 3.136).

CONCLUSION

Patients with preterm labour had a higher prevalence of poor prenatal care

and maternal hypertension. Our ndings highlight the signicance of proper

prenatal care and ecient management of hypertensive diseases throughout

pregnancy.

KEYWORDS: Preterm Labor, Moderate Preterm, Late Preterm, Maternal

Risk Factors, Inadequate Prenatal Care, Maternal Hypertension

How to cite this article

Jamil S, Afridi F, Javid W. Maternal

Risk Factors for Moderate and Late

Preterm Labour: A Case-Control

Study from a Tertiary Care Hospital in

Peshawar. J Gandhara Med Dent Sci.

2026;13(1):54-59.

Date of Submission: 20-08-2025

Date Revised: 15-12-2025

Date Acceptance: 16-12-2025

Postgraduate Trainee, Obstetrics and

Gynaecology, Khyber Teaching Hospital,

Peshawar

Correspondence

Fauzia Afridi, AssociateProfessor,

Obstetrics and Gynaecology, Khyber

Teaching Hospital, Peshawar

+92-333-9154231

afridifauzia@gmail.com

INTRODUCTION

Every neonate delivered before 37 weeks of gestational

age (GA) is considered preterm, according to WHO.

Infants delivered within 34 and 36 weeks and six days

are considered late preterm, while those born before 28

weeks are considered very premature.

With over one

million fatalities annually globally, prematurity is the

primary cause of death and disability among infants,

occurring in over 10% of births. Basic medical care and

inexpensive treatments can avert the majority of these

fatalities.

Premature labor is the primary maternal

problems that result in late preterm delivery.

Twin

pregnancies, hypertensive illness, gestational diabetes,

and urinary tract infections are among the other

obstetric disorders that can cause preterm birth. The

unsettling fetal state and limited intrauterine growth are

two of the primary fetal reasons.

The relationship

between GA and the risk of newborn problems is

inverse. The fetus’s growth advances, and the incidence

and intensity of newborn problems decrease with each

passing week it stays in the uterus.

The likelihood of

adverse eects from late prematurity is approximately

seven times greater than that of term infants (TI). These

initial issues encompass breathing diculty, failure to

maintain temperature, low blood sugar, elevated

bilirubin levels, eating challenges,

CNS underdevelopment, and exposure to microbes.

addition, compared to term newborns, the possibility of

hospital admission and morbidity is increased

throughout the rst year of life.

In a study, intrauterine

growth retardation was observed in 24.1% patients with

moderate and late preterm as compared to 7.8% with

term labor. Inadequate visits were reported in 76.9%

patients with preterm labor as compared to 60.3%

patients with term labor. Maternal hypertension was

observed in 29.8% patients with moderate and late

preterm as compared 11.9% with term infants.

The

lack of information on the risk factors for moderate and

late preterm birth in our community prompted the

https://doi.org/10.37762/jgmds.13-1.776

January - March 2026

J Gandhara Med Dent Sci

planning of this study. Because preterm birth has

several clinical and economic ramications, it is

essential to understand the variables that contribute to

moderate and late preterm birth. Our study’s ndings

will help ll this information gap. Better counseling of

expectant mothers with possible risk factors regarding

the course of their pregnancy might also benet from it.

METHODOLOGY

This case-control study was conducted at the

Department of Obstetrics and Gynecology, Khyber

Teaching Hospital, Peshawar, during the period March

1, 2024, to August 31, 2024. Women aged 18 to 40

years with gestational age 32 to 36

weeks as per last

menstrual period were contrasted, for maternal risk

factors including inadequate prenatal care and maternal

hypertension, with healthy controls. Patients with a

prior history of cesarean delivery, patients with medical

conditions such as thyroid disorder, multiple

pregnancies on ultrasound, babies with congenital

anomalies, and intrauterine death were excluded.

Preterm labor was dened by labor onset prior to 37

weeks of gestation. Labor onset between 32 and 33+6

weeks was called moderate preterm, and 34 to 36+6

weeks were called late preterm, which were considered

cases. Healthy controls included patients with an onset

of labor at 37 weeks of gestation or later. Maternal risk

factors evaluated included inadequate prenatal care,

defined as fewer than three medical visits during

pregnancy, regardless of gestational age. Maternal

hypertension was dened as blood pressure more than

140/90mmHg measured using a sphygmomanometer,

during pregnancy on two or more occasions at least 4

hours apart. It was hypothesized that maternal

hypertension and inadequate antenatal care are

associated with moderate and late preterm labor (i.e.,

odds ratio more than 1). Sample size was 274 (137 in

each group), calculated using the WHO sample size

formula, with anticipated proportions of inadequate

visits in patients with preterm and term labor set at

76.9% and 60.3%, respectively, 80% power of the test,

and a 95% condence level. Participants were recruited

using non-probability consecutive sampling. Patients

fulfilling the inclusion criteria were enrolled from the

hospital‘s indoor department after obtaining approval

from the institute‘s research review board and the

CPSP. Informed consent was taken from all study

participants after explaining the purpose, risks, and

benets of the study. Baseline information, including

age (years), gestational age (weeks), BMI (kg/m

residence, profession, education, and socioeconomic

status, was recorded. All patients were evaluated for

maternal risk factors. For maternal risk factors, history

was taken about previous history of hypertension.

Blood pressure was recorded in the lying position on

two occasions at least 4 hours apart using a

sphygmomanometer. History was taken regarding the

number of visits the patients made during the entire

length of pregnancy. The number of visits documented

in the medical record during the period of gestation was

noted. Maternal risk factors were noted as per

operational denitions. Data were analyzed using IBM

SPSS Statistics version 24. Frequencies and

percentages were computed for qualitative variables,

including residence, profession, education,

socioeconomic status, parity, and maternal risk factors

(hypertension and inadequate antenatal care). Means ±

S.D. or median (IQR) were computed for quantitative

data on age, gestational age, and BMI after checking

the normality of the data using the Shapiro-Wilk test.

The association between maternal risk factors and

moderate/late preterm was measured using the chi-

square test at the 5% level of signicance, with p-

values ≤0.05 considered statistically signicant. Odds

ratios for maternal risk factors (hypertension and

inadequate antenatal care) were calculated using a 2x2

table to measure the strength of association. 95% CI for

the odds ratio was calculated. Odds ratios with 95% CIs

excluding one were considered signicant. Eect

modifiers such as age, gestational age, parity, BMI,

residence, education, profession, and socioeconomic

status were controlled for by stratication. A post-

stratication chi-square test at the 5% signicance level

was applied. P-value ≤0.05 was considered statistically

significant. A multivariate logistic regression model

was used to identify independent predictors of preterm

labour.

RESULTS

The mean age of the cases was 29.14±6.239 years

compared to 27.91±6.754 years in controls. The mean

gestational age in cases and controls was 33.88±1.372

weeks and 38.78±1.439 weeks, respectively. Sixty-four

patients (55.7%) in the cases were aged more than 30

years, compared to 51 patients (44.3%) among controls

(p value 0.112). Among cases, 112 patients (49.1%)

were multiparous, versus 116 (50.9%) among controls

(p value 0.901). No statistically signicant dierence

was observed between cases and controls regarding

socioeconomic status (p-value 0.468); however, a

significant dierence in profession distribution was

observed (p-value 0.034). Overall, inadequate prenatal

care was recorded in 85 participants, of whom 53

(62.4%) were cases and 32 (37.6%) were controls (p

value 0.006; OR 2.070 [95% CI 1.226-3.497]).

Maternal hypertension was recorded in 74 patients,

more frequently among cases (n = 45, 60.8%) than

among controls (n = 29, 39.2%), with an OR of 1.822

Maternal Risk Factors for Moderate and Late Preterm

January - March 2026

J Gandhara Med Dent Sci

(95% CI 1.058 - 3.136). Stratication of inadequate

prenatal care by age showed no statistically signicant

dierence (p-value = 0.726). 49 patients (29.3%) with

BMI 25.0 kg/m2 or below received inadequate care,

compared to 36 patients (33.6%) with BMI> 25.0

kg/m

, p value 0.452. Inadequate care was observed in

16 (34.8%) primiparous patients, compared with 69

(30.3%) multiparous patients (p value 0.546). No

statistically signicant association was observed with

other parameters (p value > 0.05). Forty-one patients

(25.8%) aged 30 years or below had maternal

hypertension versus 33 (28.7%) aged more than 30

years. The p-value was 0.592. The p-value for the

difference in distribution by BMI was 0.419. Sixteen

patients (34.8%) with maternal hypertension were

primiparous versus 58 (25.4%) multiparous patients (p

value 0.193). A binary logistic regression model was

constructed to assess the eect of baseline variables on

outcome parameters. However, no statistically

signicant eect was observed (p value >0.05, OR ≈ 1

and 95% CI for odds ratio included 1).

Table 1: Distribution of Patients According to Baseline

Parameters (n = 274)

Group P-Value

Cases

(n=137)

Controls

(n=137)

Age

(years)

30 or below 73 86 0.112

45.9% 54.1%

More than

64 51

55.7% 44.3%

BMI

(kg/m

)

25.0 or

below

83 84 0.901

49.7% 50.3%

More than

25.0

54 53

50.5% 49.5%

Parity Primiparous 25 21 0.901

54.3% 45.7%

Multiparous 112 116

49.1% 50.9%

SES Fair 61 67 0.468

47.7% 52.3%

Poor 76 70

52.1% 47.9%

Profession House wife 105 89 0.034

54.1% 45.9%

Professional 32 48

40.0% 60.0%

Residence Rural 73 79 0.466

48.0% 52.0%

Urban 64 58

52.5% 47.5%

Education No formal

schooling

34 18 0.037

65.4% 34.6%

Matric or

below

61 76

44.5% 55.5%

Above

matric

42 43

49.4% 50.6%

Table 2: 2x2 Table Analysis and Odds Ratio for Outcome

Variables (n = 274)

Outcome

variables

Group P-Val

Odds

ratio

Cases Controls

Inadequate

Prenatal Care

Yes 53 32 0.006

2.070

(1.226 -

3.497)

62.4% 37.6%

No 84 105

44.4% 55.6%

Maternal

Hypertens

ion

Yes 45 29 0.029

1.822

(1.058-

3.136)

60.8% 39.2%

No 92 108

46.0% 54.0%

Table 3: Stratication of Inadequate Prenatal Care with Baseline

Parameters (n = 274)

Inadequate

Prenatal Care

P-Value

Yes

(n=85)

(n=189)

Age

(years)

30 or below 48 111 0.726

30.2% 69.8%

More than

37 78

32.2% 67.8%

BMI

(kg/m

)

25.0 or

below

49 118 0.452

29.3% 70.7%

More than

25.0

36 71

33.6% 66.4%

Parity Primiparous 16 30 0.546

34.8% 65.2%

Multiparous 69 159

30.3% 69.7%

SES Fair 42 86 0.549

32.8% 67.2%

Poor 43 103

29.5% 70.5%

Profession House wife 64 130 0.273

33.0% 67.0%

Professional

21 59

26.3% 73.8%

Residence Rural 47 105 0.968

30.9% 69.1%

Urban 38 84

31.1% 68.9%

Education No formal

schooling

18 34 0.355

34.6% 65.4%

Matric or

below

37 100

27.0% 73.0%

Above

matric

30 55

35.3% 64.7%

Maternal Risk Factors for Moderate and Late Preterm

January - March 2026

J Gandhara Med Dent Sci

Table 4: Stratication of Maternal Hypertension with Various

Parameters (n = 274)

Maternal

Hypertension

P-

Value

Yes

(n=74)

(n=200)

Age

(years)

30 or below

41 118

0.592

25.8% 74.2%

More than

33 82

28.7% 71.3%

BMI

(kg/m

)

25.0 or

below

48 119

0.419

28.7% 71.3%

More than

25.0

26 81

24.3% 75.7%

Parity

Primiparous

16 30

0.193

34.8% 65.2%

Multiparous

58 170

25.4% 74.6%

SES

Fair

35 93

0.907

27.3% 72.7%

Poor

39 107

26.7% 73.3%

Profession

House wife

50 144

0.474

25.8% 74.2%

Professional

24 56

30.0% 70.0%

Residence

Rural

44 108

0.419

28.9% 71.1%

Urban

30 92

24.6% 75.4%

Education

No formal

schooling

09 43

0.204

17.3% 82.7%

Matric or

below

39 98

28.5% 71.5%

Above

matric

26 59

30.6% 69.4%

Table 5: Logistic regression analysis predicting inadequate

prenatal care and maternal hypertension (n = 274)

Depend

ent Vari

ables

Predic

tors

B S.E.

Wald

Sig.

95% CI

for OR

Lower

Inadequ

ate

prenatal

care

Age -.114

.268

.182

1 .670

.892

.528 1.508

BMI -.163 .273

.359

1 .549

.849

.497 1.450

Parity .178

.348

.262

1 .609

1.195

.604 2.364

SES .168

.268

.393

1 .531

1.183

.700 1.998

Profes

sion

.308

.301

1.053

1 .305

1.361

.755 2.454

Reside

nce

-.013

.268

.002

1 .962

.987

.583 1.671

Educat

ion

-.055

.191

.082

1 .775

.947

.651 1.377

Materna

l HTN

Age -.124

.281

.195

1 .659

.883

.510 1.532

BMI .254

.292

.761

1 .383

1.290

.728 2.285

Parity .398

.353

1.266

1 .260

1.489

.745 2.976

SES .098

.281

.121

1 .728

1.103

.635 1.914

Profes

sion

-.201

.300

.447

1 .504

.818

.454 1.473

Reside

nce

.130

.283

.211

1 .646

1.139

.654 1.982

Educat

ion

-.305

.203

2.249

1 .134

.737

.495 1.098

Upper

DISCUSSION

Pakistan has 21.6% preterm birth rate, which is

comparable to other developing nations and far higher

than that of industrialized nations.

This case-control

study assessed the maternal risk factors associated with

moderate and late preterm birth in a tertiary care setting

in Pakistan. The ndings demonstrated that inadequate

prenatal care and maternal hypertension were

significantly associated with preterm labor, which

aligns with previously reported literature. While most

baseline demographic characteristics, such as maternal

age, BMI, parity, socioeconomic status, and residence,

did not dier signicantly between groups, our study

found a statistically signicant dierence in education

level (p = 0.037). A greater proportion of women in the

preterm group had no formal schooling compared to

controls. These ndings suggest that lower educational

attainment may contribute to an increased risk of

preterm birth, possibly due to limited health literacy or

reduced access to healthcare resources. These

associations merit further exploration in future

studies.

11,12

Maternal hypertension was another

significant risk factor identied in our study. Among

preterm cases, 60.8% had hypertension compared to

39.2% of controls (p = 0.029; OR 1.82, 95% CI: 1.06-

3.14). This nding corroborates earlier research by

Brown et al. and Araújo et al., which demonstrated that

hypertensive disorders in pregnancy, primarily

preeclampsia, are strongly associated with placental

insuciency and increased rates of medically indicated

preterm birth.

4,13

Hypertension compromises

uteroplacental blood ow, potentially leading to fetal

growth restriction and premature labor induction.

Numerous studies link insucient prenatal care to

preterm birth.

14,15

Our results showed that inadequate

prenatal care, dened as fewer than three visits during

pregnancy, was signicantly more common among

women who delivered preterm than among those with

term deliveries (62.4% vs. 37.6%, p = 0.006; OR 2.07,

95% CI: 1.23-3.50). This observation is consistent with

studies by Razeq et al. and Machado et al., which found

that reduced antenatal visits are associated with an

increased risk of preterm delivery.

12,16

Poor attendance

at prenatal clinics may lead to missed opportunities for

early detection and management of pregnancy

complications, thereby increasing the risk of adverse

outcomes such as preterm birth. Approximately two-

thirds of the late preterm babies in previous research

were spontaneous preterm deliveries. Recognizable risk

variables, including diabetes, hypertension, and fetal

distress, accounted for the remaining third.

17,18

A minor

fraction lacked a discernible risk factor, which may

Maternal Risk Factors for Moderate and Late Preterm

January - March 2026

J Gandhara Med Dent Sci

have been caused by surgical decision-making or

inadequate reporting of maternal or fetal diseases.

19,20

The clinical implications of our ndings are

considerable. Emphasizing the importance of regular,

high-quality antenatal care can enable earlier

identification and management of maternal conditions,

such as hypertension. Public health strategies should

therefore include strengthening community-level

awareness and improving access to antenatal services,

particularly in underserved populations. Moreover,

targeting educational interventions to less educated

women and homemakers may further reduce the burden

of preterm birth. The strengths of this study include its

prospective design, standardized data collection

methods, and operational denitions, which enhance

methodological rigor. Moreover, the study population

was adequately matched, and confounding variables

were addressed using logistic regression, thereby

strengthening the internal validity of this study.

LIMITATIONS

First, it was conducted at a single tertiary care hospital,

which may limit the generalizability of the ndings to

other settings, particularly rural areas. Second, the use

of non-probability consecutive sampling could

introduce selection bias. Third, the reliance on self-

reported data in the absence of medical records for

antenatal care visits introduces the potential for recall

bias. Fourth, although key maternal risk factors were

considered, unmeasured confounders such as nutritional

status, psychosocial stress, and environmental

exposures were not accounted for. Lastly, maternal

hypertension was analyzed as a single entity, as it was

not always possible to dierentiate reliably between

chronic hypertension, gestational hypertension, and

preeclampsia, due to the late booking of some patients.

CONCLUSIONS

Inadequate prenatal care and maternal hypertension are

significant contributors to moderate and late preterm

labor in our population, almost doubling the risk.

Focused antenatal interventions, educational support,

and improved maternal health surveillance, including

regular blood pressure monitoring, can mitigate these

modifiable risk factors for preterm labor. Future

multicenter studies with larger sample sizes and broader

risk-factor assessment are recommended to elucidate

the determinants of preterm birth in Pakistan.

CONFLICT OF INTEREST: None

FUNDING SOURCES: None

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Maternal Risk Factors for Moderate and Late Preterm

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Unveiling the Silent Epidemic of Uterine Prolapse

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Sara Jamil - Concept & Design; Data Acquisition; Data

Analysis/interpretation; Drafting Manuscript; Final Approval

Fauzia Afridi - Concept & Design; Data Acquisition; Drafting

Manuscript; Critical Revision; Supervision; Final Approval

Wajeeha Javid - Concept & Design; Data Acquisition; Drafting

Manuscript; Final Approval

AUTHORS CONTRIBUTION

The authors accept responsibility for all aspects of the work

and will ensure that any concerns regarding the accuracy or

integrity of any part are properly investigated and resolved.

Maternal Risk Factors for Moderate and Late Preterm

January - March 2026