Preterm birth associated factors. A case-control study.

doi:10.21203/rs.3.rs-3146832/v1

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Preterm birth associated factors. A case-control study.

https://doi.org/10.21203/rs.3.rs-3146832/v1

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Background: Preterm births are an increasing trend globally, and it demands healthcare and social support. Thus, studying the sociodemographic risk factors associated with preterm birth reflects a better understanding and enables the development of efficient, cost-effective maternal health services.

Objective: To assess the association between pregnancy planning and preterm birth. Then, our secondary objective is to investigate the sociodemographic factors among preterm and full-term delivered women.

Methods: A case‒control study was conducted on n=391 postpartum women. Fifty-two preterm births (cases) and 339 full-term births (controls) were performed in a referring hospital in Hofuf, Saudi Arabia. A survey is collected from postpartum women rating pregnancy planning practices and other sociodemographic characteristics.

Results: The majority, 85% of the sample, were housewives, and 80% were within a low-income category earning less than 10,000 SR per month for both preterm and full-term mothers. We found a greater odds of having chronic illness during pregnancy (OR= 1.76, 95% CI (1.062, 2.917)) the preterm birth mothers.

Conclusion and recommendation: Our study highlighted the preterm associated risk factors namely, presence of pregnancy illness, more likely to end by cesarian section, and to have a neonatal complication. Thus, the result highlighted the need for careful antenatal care pregnancy management for women with chronic illness such as diabetes, and hypertension. Therefore, we also recommend pregnancy preparation and planning for healthy pregnancy specially for high-risk pregnancy.

Preterm births are an increasing trend globally, drawing researchers' attention due to their economic and social impact. It not only affects the family but also demands healthcare and social support.

Economic and social burden

a recent review conducted by Salimah et al. elaborated on the need for collaborative efforts for preterm birth, as it accounts for approximately 11% of the total annual births (1), and that rate could be imprecise, as the available data are scarce, which hinders the attainment of the third sustainable developmental goal in ending preventable newborn deaths and under five years of age to less than 12 per 1,000 live births and 25 per 1,000 live births, respectively, by 2030.

Psychosocial risk evidence for preterm births

Studying the sociodemographic risk factors associated with preterm birth reflects a better understanding and enables the development of efficient, cost-effective maternal health services. Many risk factors are associated with preterm birth, including intrapersonal, interpersonal, and community factors.

Stressors during pregnancy have a shred of evidence to be a contributing factor for PTB, with an adjusted odds ratio (AOR) of 2.15 for preterm birth (2). Thus, we can assume that providing social support would prevent the harmful effect on pregnancy. Moreover, Hetherington et al. studied the estimated risk of psychological stress during pregnancy in a systematic review and meta-analysis (3). However, the risk estimate analysis had high heterogeneity for social support as a beneficial factor that could prevent preterm birth (as a binary outcome). Other studied risk factors were tobacco smoking and family economic status; thus, low family income increases the odds of having a preterm birth (AOR = 2.62, 95% CI = 1.03–6.66 and AOR = 4.63, 95% CI = 1.62–13.27, respectively) (4).

In contrast, other risk factors would require healthcare providers' vigilance, such as high maternal age for 35-year-old women and older, which increased the odds of preterm birth regardless of the mother's parity and existing medical illness (5). Furthermore, consanguinity has impactful evidence on preterm birth (PTB). PTB had an AOR of nearly four times the full-term birth rate in a first-degree consanguineous couple (AOR = 3.72, 95% CI = 1.52–9.12) (4). Marriage inside families is common in the Middle East and occurs for many social reasons; above them is to keep the wealth inside the family.

Unplanned pregnancy and maternal and fetal negative outcomes

An unplanned pregnancy is linked to multiple adverse outcomes, as it might end with unsafe abortion, maternal death, and psychological burden (6). In contrast, if it ended with delivery, it would be premature. Furthermore, a previous prospective study in the US concluded that preterm birth was most likely due to unwanted pregnancy (6).

Our current study intends to measure planning pregnancy by its six domains structured by Professor Barrett in the UK and validated for Arabic-speaking women (7). Measuring pregnancy planning and finding its sociodemographic correlates would widen our understanding of matero-fetal negative outcomes, namely, preterm birth, low birth weight, and postpartum depression.

Research questions or hypothesis:

Significance/Contribution:

Measuring pregnancy planning (preparation) and correlating its risk with pregnancy outcomes would guide public health efforts and maternal health services in providing the essential needs to ensure positive and healthy pregnancy outcomes.

Aims and Objectives:

The primary objective is to assess the statistical association between pregnancy planning and preterm birth.

Secondary objective

To investigate the sociodemographic factors among preterm and full-term delivered women.

We wanted to investigate whether pregnancy planning and preparation, as recommended by the WHO and various national and international entities, had higher or lower odds of preterm birth, low birth weight, intrauterine growth retardation (IUGR), and maternal postpartum depression.

We conducted a nonmatched case‒control study. As preterm birth is a rare observation, it is more convenient, time- and cost-efficient to conduct than a prospective cohort study design.

Population and sample:

Setting

The study was conducted in the maternity and children's hospital in AlAhsa, located in the eastern region of Saudi Arabia. The hospital is a governmental public hospital that serves Saudi citizens free of charge. Moreover, the hospital is the main referred hospital in AlAhsa.

The King Fahad Hospital Institutional Review Board (IRB) KFHH No. (H-05-HS-065) was granted before data collection with IRB Log No: 72-EP-2022 that ensures participant's rights and data confidentiality.

Cases

The study cases included postpartum women who were admitted for delivery at less than 37 weeks (either calculated since her last menstrual period or confirmed by ultrasound) as defined by the World Health Organization (WHO) ("Preterm Birth," 2018).

Controls

full-term delivered mothers, defined as women who deliver after 38 weeks that started spontaneously or medically induced with all modes of deliveries. Moreover, the sample size is calculated based on an estimated 5% type I error and at 80% statistical power with at least an odds ratio (OR) of 2 for unplanned pregnancy (9) with the proportion of controls to be exposed (unplanned) 53% (7). An additional 20% (31 for each arm) was added to account for any missing data, with a total of 366 participants. Furthermore, we excluded multiple pregnancies, congenital birth defects, and fetal death, to account for the confounding effect as they have a risk of preterm birth.

Data collection:

Procedure:

The participants were recruited by a trained Arabic-speaking nurses familiar with postpartum women from the local hospital staff. The sampling frame consisted of the delivery list and consecutive mothers' selection from December 1st, 2022, until the end of March 2023.

The data collection form:

The trained nurses collected the data in the predesigned Google form that had been tested previously. The data collection form consists of three main parts. First, sociodemographic information on the participant's age, level of attained education, number of pregnancies, number of children, consanguinity, monthly household income, and household help by family or housemaid. The second part was asking about pregnancy planning items as discussed below. Then, the third part which is acquiring antenatal and postpartum (child and maternal) outcomes as number of antenatal visits, clinical illness during pregnancy, mode of delivery, child birth weight, medical complications if any for both mother and children.

Instrument:

Pregnancy planning measure:

We used the London Measure of Unplanned Pregnancy (LMUP), which was validated for Arabic-speaking women and has high validity and reliability, which asks test takers about preconception preparation in six domains: discontinuation of contraceptive methods used before conception, the timing of conception, intention, and desire to have a baby, discussion with her partner about conception, and preconception preparation.

The LMUP scoring ranged from 0–12 for six questions, and each question scored 0–2. The higher the score, the higher the pregnancy planning and intention. Avoiding dichotomous answers in scoring this measure as planned and unplanned permits measurement of the ambivalence of pregnancy intention. Therefore, the results should report the full range of scores gathered, as that will yield additional information. Another suggestion provided by Barrett was displaying a score cut point as less than three indicates unplanned, more than 10 indicates planned pregnancy, and scores in between indicate ambivalence of planning pregnancy (10).

Data analysis:

The data were cleaned and coded using SPSS software after retrieval from Google Forms. All downloaded data was coded before the analysis through concatenation (joining the first three numbers of the national ID and the last three numbers of the medical records with four digits of the year of birth).

The analysis included descriptive correlation test examining the sociodemographic factors among preterm and full-term births by frequency and percentages such as maternal age, maternal education, job, and parity. Additionally, analytical statistical testing was conducted using binary logistic regression to measure the Odd Ratio (OR) of having preterm birth among planned and unplanned pregnancy with their 95% CI, and different obstetric and sociodemographic factors.

The sample consisted of 52 preterm and 339 full-term immediate postpartum women. Their mean (S.D.) age was 31.21± 6.06 and 30.81± 6.47, with a non-statistically significant p value demonstrating group similarity. Thus, it is appropriate to conduct a bivariate analysis. [Table 1] illustrates the distribution of sociodemographic factors between the two groups. The median number of previous pregnancies for full-term and preterm births were 4 (IQR 2, 5) and 3.5 (IQR 2, 6), respectively. The majority, 85% of the sample, were housewives, and 80% were within a low-income category for both groups, earning less than 10,000 SR equal to $ 2,666 per month.

Moreover, there were no significant association found between mothers with preterm births and most of the sociodemographic factors such as job, household assistance, family income, consanguinity, and number of antenatal follow-up visits [Table 2]. However, preterm birth mothers had greater odds of having chronic illness during pregnancy (OR= 1.76, 95% CI (1.062, 2.917)) than full-term pregnancies.

Furthermore, we investigated the preterm-associated outcomes, confirming the known parameters: preterm infants are more likely to have neonatal complications, such as respiratory distress, or septicemia [Table 3]. Moreover, we found that PTB had significantly higher odds of being delivered by cesarian section four times than a full-term birth.

This study investigated the association between sociodemographic factors and preterm birth in AlAhsa Oasis. A statistically significant association was found between maternal educational level and maternal medical illness.

We investigated the known sociodemographic correlates with preterm birth and found some discrepancies. First, the low monthly family income was not statistically significant between preterm and full-term deliveries, as most of the sample was within the low-income status. It might also be related to the study location, as our study was conducted in a governmental free-of-charge hospital. In contrast, Wahabi et al. found (AOR = 4.63, 95% CI = 1.62–13.27) preterm birth within a low-income participant, as their sample was in the capital of Saudi Arabia (Riyadh city), and their sample was collected from three large hospitals (4), which contains variability in the included sample. Similarly, consanguinity did not exhibit statistical significance (p value.307), as seen in other literature (OR of 3.73 96% CI = 2.19–6.37 and OR of 2.71 95% CI = 1.57–4.68 combined (4)(11) to be associated with preterm birth. Therefore, we investigated preterm birth outcomes to assert the sample representativeness of the general preterm population.

The preterm outcome has more than four times the odds of cesarian section delivery vs. full-term births. Our results are similar to the evidence in a prospective multicenter study conducted with more than thirteen thousand women with a doubled risk for preterm birth associated with cesarian delivery (12).

Furthermore, inadequate antenatal visits (ANC) during pregnancy, i.e., fewer than four, were associated with significant odds for preterm birth (OR 3.40, 95% CI 1.65–7.02) (11). However, our sample did not show similar results, as 92% of both groups attended four or more ANC visits. Thus, our result could be attributed to the mother's awareness, care, and the existing healthcare system's primary healthcare needs for women's health.

As per the WHO recommendation to have a folic Acid supplements three months before pregnancy as it is the six item in the pregnancy planning measure (LMUP). However, we did not find statistical correlation between pregnancy planning score and preterm birth. Non the less, our result is in line with the previous large prospective cohort study by Gariepy et al., who found no association between PTB and small for gestational age birth with pregnancy planning [OR] 1.18; 95% confidence interval [CI], 0.85–1.65) (OR 1.17; 95% CI, 0.69–1.97)(13)(14).

Strengths and limitations

To our knowledge, this is the first study of pregnancy planning and its related outcomes in Saudi Arabia. However, we have to acknowledge some limitations other than the retrospective nature of the study that may contribute to reporting bias and recall bias. Meanwhile, recall bias is expected to be random in the cases as well as the controls equally, as we did not specify pregnancy planning or preterm birth terms during the study description before participation. Furthermore, we could not achieve the desired sample size of the controls for administrative difficulties, although we believe that that would not change the result, as the cases represented nearly 13% of the actual prevalence of preterm birth in the community. Moreover, selecting one governmental hospital would not be representative of the chosen city or the general population. Thus, we recommend larger, multicenter, prospective studies that measure wider determinants of health that enable a better conclusion to facilitate healthy pregnancies.

Our study highlighted the preterm associated risk factors namely, presence of pregnancy illness, more likely to end by cesarian section, and to have a neonatal complication. Thus, the result highlighted the need for careful antenatal care pregnancy management for women with chronic illness such as diabetes, and hypertension. Therefore, we also recommend pregnancy preparation and planning for healthy pregnancy specially for high-risk pregnancy.

Ethics approval and consent to participate

The King Fahad Hospital Institutional Review Board (IRB) KFHH No. (H-05-HS-065) was granted before data collection with IRB Log No: 72-EP-2022 that ensures participant’s rights and data confidentiality. And all participants were consented verbally ahead of participation were they assured of the data confidentiality.

Consent for publication

Not applicable

Availability of data and materials

The data are can be available upon a reasonable request from the primary investigator E.A.

Competing interests

Authors declare that they have no conflict of interests

Funding and financial support

None.

Authors’ contributions

A.A. reviewed and approved the proposal, provided advice on data analysis and interpretation, and reviewed the final manuscript; E.A. and K.A. conceived the research idea with Proposal development and revision; E.A. wrote the proposal, conducted the data verification, cleaning, and analysis; and handled manuscript writing. The research logistic and administrative assistance, along with data acquisition collaboratively conducted by Z.A., J.A., W.A., M.A., and H.A.

Acknowledgments

My thanks are extended to all the mothers who participated in this study and the nurses in the postnatal wards who participated in data collection. I would also like to thank the Joint Program of Preventive Medicine in Al-Ahsa for their academic support.

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Tables 1 to 3 are available in the Supplementary Files section

No competing interests reported.

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Version 1

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You are reading this latest preprint version

Preterm birth associated factors. A case-control study.

Status:

Version 1

Abstract

Introduction

Psychosocial risk evidence for preterm births

Unplanned pregnancy and maternal and fetal negative outcomes

Research questions or hypothesis:

Significance/Contribution:

Aims and Objectives:

Research design and method

Population and sample:

Setting

Data collection:

Procedure:

The data collection form:

Instrument:

Data analysis:

Results

Discussion

Strengths and limitations

Conclusion

Declarations

References

Tables

Additional Declarations

Supplementary Files

Status:

Version 1