Vaginal bleeding during pregnancy: a retrospective cohort study assessing maternal and perinatal outcomes

Abstract

Objective

Vaginal bleeding is a relatively common problem during pregnancy, with up to 25% of women experiencing some level of bleeding or spotting during pregnancy. Although not always a concern, pregnancy-related vaginal bleeding may detrimentally impact maternal and fetal health, and can arise at any stage during the pregnancy, usually linked with preterm labor, miscarriage, placental abnormalities, or implantation bleeding. As vaginal bleeding may compromise newborn health outcomes, for example, leading to low birth weight and neonatal intensive care unit (NICU) hospitalizations, it is imperative to understand the etiology of the bleed and effectively manage the patient’s condition. Thus, the aim of this study was to evaluate the prognostic value of vaginal bleeding as an indicator for at-risk pregnancies, aiming to elucidate its association with perinatal outcomes and pregnancy complications.

Methods

Consecutive pregnant female patients, aged 16–47 years, were included in this retrospective cohort study, and categorized into those with or without pregnancy-associated bleeding. Between-group differences and correlations in pregnancy complications and perinatal outcomes were statistically analyzed.

Results

Among a total of 441 patients, the incidence of vaginal bleeding was 74.4%, predominantly occurring in the first trimester (67.1%). No significant association was found between bleeding and maternal age, parity, abortion history, or total number of pregnancies. Educational level varied, with 64.9% of moderate education level experiencing bleeding. Pre-pregnancy comorbidities, such as diabetes, hypertension, and hypothyroidism, were not significantly correlated with bleeding. However, a history of infertility and progesterone treatment during pregnancy was significantly associated with bleeding episodes. An increased risk for NICU admissions and conditions such as respiratory distress in neonates was found, alongside a significant association with post-delivery bleeding and premature labor in the later trimesters.

Conclusions

Vaginal bleeding during pregnancy was not found to be significantly associated with maternal age, parity, abortion history, or total pregnancies. Nonetheless, the findings suggest a significant relationship between bleeding episodes and a history of infertility or progesterone treatment during pregnancy. Additionally, pre-pregnancy comorbidities, including diabetes, hypertension, and hypothyroidism were not associated with pregnancy bleeding. However, the latter was associated with increased risk of post-delivery bleeding, premature labor, and neonatal complications, such as respiratory distress and NICU admissions.

Keywords

Vaginal bleeding in pregnancy Maternal outcomes Perinatal outcomes Pregnancy complications Early intervention Diagnostic approaches in pregnancy Treatment options for pregnancy bleeding Pregnancy risk indicators

Introduction

Vaginal bleeding during pregnancy represents a clinical spectrum ranging from mild spotting to severe hemorrhage, with significant implications for pregnancy outcomes. Its prevalence varies throughout the gestational phases, each characterized by specific etiologies and associated risks. Effective management and early intervention in cases of vaginal bleeding are paramount in safeguarding both maternal and fetal health^1,2

This bleeding can arise from a multitude of factors, differentiated by the gestational period. Early in pregnancy, the integrity of local and systemic hemostatic mechanisms within the uterus is essential for maintaining pregnancy. Dysregulation of these mechanisms, including the aberrant expression of tissue factors by cytotrophoblasts or the local generation of thrombin and soluble fms-like tyrosine kinase-1, can precipitate bleeding episodes.^1–4

While implantation bleeding is considered a physiological event, occurring in approximately 25% of pregnancies as the zygote attaches to the uterine lining, other causes, such as ectopic pregnancies, miscarriages, and molar pregnancies, are also associated with pathological risks.^4–9 Moreover, bleeding may emanate from non-pregnancy related pathologies, including cervical or vaginal disorders, such as erosions, polyps, fibroids, cancer, or trauma.^1–5

According to the current body of literature, about 15–25% of pregnancies are reported to have one form of vaginal bleeding in the first trimester and the majority of these cases were demonstrated to have an increased risk of unfavorable pregnancy outcomes, most notably: miscarriage, premature delivery, low birth weight and even stillbirth.^10–14 This type of bleeding usually stems from subchorionic hematoma and ectopic pregnancy.^11,12 In turn, these conditions may have a detrimental impact on the health of the mother and the fetus. Similarly, studies on the impact of decidual hemorrhage in relation to premature delivery found that vaginal bleeding may signify chorioamnionitis, which is detrimental to fetal development.^15,16

During the second trimester, vaginal bleeding is usually associated with placental abruption, placenta previa, or an incompetent cervix, which can lead to preterm birth.¹⁷ At a later stage, during the third trimester of pregnancy, vaginal bleeding may be observed due to placental abruption, placenta previa, or vasa previa, in addition to cervical changes or uterine fibroids.¹⁷

The primary aim of the present study was to systematically review instances of vaginal bleeding during pregnancy and their impact on gestational progression and outcomes. Secondary objectives included the evaluation of associated complications and identification of potential risk factors, with the overall aim of enhancing early diagnosis and follow-up care for pregnant women at elevated risk of adverse outcomes, emphasizing the need for tailored clinical approaches.

Patients and methods

Study design and population

In this retrospective cohort study, the medical records of pregnant women who visited a private clinic in Beirut between 2019 and 2023 were reviewed. Sample size was calculated using Slovin’s formula to ensure a 95% confidence level and a 5% margin of error. Patients were consecutively selected based on their medical records meeting inclusion and exclusion criteria, and non-bleeding controls were selected from the same clinic population.

The selection approach aimed to ensure that the participants had similar healthcare access and socioeconomic backgrounds, to help minimize confounding variables and enhance the comparability between bleeding and non-bleeding groups. All participants provided verbal informed consent to the general use of their data for research purposes (including the present retrospective study), as part of routine clinical practice on first presentation to the clinic. The study was conducted in accordance with the ethical standards of the Rafic Hariri University Hospital’s Institutional Review Board Committee, which granted approval on 2 February 2024 (registration overseen by GY). Due to the prevailing circumstances in Lebanon, a formal approval number was not issued, however, all necessary ethical guidelines and standards were strictly adhered to, ensuring the integrity and ethical compliance of the research. In addition, the study was conducted in accordance with the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) guidelines,¹⁸ and with the 1975 Declaration of Helsinki, as revised in 2013. All patient details were de-identified to ensure anonymity.

Inclusion and exclusion criteria

Inclusion criteria comprised pregnant women aged 16–47 years, with or without vaginal bleeding during pregnancy, and with documented pregnancy outcomes. Patients with coagulopathies, incomplete records, multiple gestations, or ectopic pregnancies were excluded from the study.

Data collection

Demographic details, medical histories, symptoms, and outcomes were extracted from patient records. The primary focus was on bleeding during pregnancy, while secondary outcomes included delivery type, neonatal intensive care unit (NICU) admissions, and post-delivery complications.

Statistical analyses

Categorical data are presented as n (%) prevalence or incidence, and continuous data are presented as mean ± SD. Data were analyzed using IBM SPSS software, version 27 (IBM Corp., Armonk, NY, USA). Descriptive statistics were applied for demographic and incidence analysis. Comparative analyses between groups were performed with χ²-test, Fisher’s exact test, or Mann–Whitney U-test. A P-value <0.05 was considered to be statistically significant.

Results

A total of 441 pregnant women were included in the study, and preliminary findings revealed that 328 out of the 441 patients (74.4%) experienced bleeding, predominantly in the first trimester. Variability in bleeding duration was shown among these patients, with intermittent bleeding being the most reported (139 patients [42.4%]; Figure 1).

Figure 1.

Characteristics of bleeding during pregnancy in 328 patients.

The incidence of pregnancy-related vaginal bleeding was most pronounced during the first trimester, with 67.1% (220/328) of cases occurring during this period. This was followed by the second trimester at 20.1% (66/328) and the third trimester at 12.8% (42/328).

Demographic characteristics

Demographic factors in patients who did or did not experience pregnancy bleeding are summarized in Table 1. The overall study cohort predominantly resided in city areas (91.8%), with the majority being Lebanese (66.0%), followed by Syrian (13.4%), Palestinian (7.0%), and other nationalities (13.6%). No statistically significant differences in bleeding incidence were observed based on location of residence or nationality (P = 0.626 and 0.593, respectively). A notable finding was the significant association between educational level and the incidence of bleeding (P = 0.003), with a higher prevalence among women with moderate education (64.9%) versus those with low (22.3%) or high education levels (12.8%).

Table 1.

Demographic characteristics in patients with or without bleeding during pregnancy.

Characteristic	Pregnancy bleeding		Total (n = 441)	Statistical significance^a
Characteristic	No (n = 113)	Yes (n = 328)	Total (n = 441)	Statistical significance^a
Residence location				P = 0.626
City	105 (92.9%)	300 (91.5%)	405 (91.8%)
Urban	8 (7.1%)	28 (8.5%)	36 (8.2%)
Education level				P = 0.003
Low	9 (8.0%)	73 (22.3%)	82 (18.6%)
Moderate	89 (78.8%)	213 (64.9%)	302 (68.5%)
High	15 (13.3%)	42 (12.8%)	57 (12.9%)
Nationality				P = 0.593
Lebanese	79 (69.9%)	212 (64.6%)	291 (66.0%)
Syrian	12 (10.6%)	47 (14.3%)	59 (13.4%)
Palestinian	9 (8.0%)	22 (6.7%)	31 (7.0%)
Other	13 (11.5%)	47 (14.3%)	60 (13.6%)

Data presented as n (%) prevalence.

Statistically significant difference at P < 0.05 (χ²-test or Mann–Whitney U-test).

Medical/obstetric history and obstetric and pre-pregnancy comorbidities

Comparative data regarding medical/obstetric histories and pre-pregnancy comorbidities in patients with or without pregnancy bleeding are summarized in Table 2.

Table 2.

Medical history and pre-pregnancy comorbidities in patients with or without bleeding during pregnancy.

Characteristic		Pregnancy bleeding		Total (N = 441)	Statistical significance
Characteristic		No (n = 113)	Yes (n = 328)	Total (N = 441)	Statistical significance
Body mass index, kg/m²	22–32	1 (0.9%)	3 (0.9%)	4 (0.9%)	P = 0.893^a
	32–35	44 (38.9%)	136 (41.5%)	180 (40.8%)
	>35	68 (60.2%)	189 (57.6%)	257 (58.3%)
Age, years	Mean ± SD	28.45 ± 5.03	28.47 ± 4.83	28.46 ± 4.87	P = 0.977^a
Age, years	Min–Max	16–47	18–45	16–47	P = 0.977^a
Parity	Mean ± SD	2.20 ± 1.40	2.03 ± 1.29	2.07 ± 1.32	P = 0.222^a
Parity	Min–Max	0–7	0–7	0–7	P = 0.222^a
History of abortion	Mean ± SD	0.74 ± 1.18	0.66 ± 0.91	0.68 ± 0.99	P = 0.448^a
History of abortion	Min–Max	0–4	0–6	0–6	P = 0.448^a
Gravida	Mean ± SD	2.95 ± 2.25	2.69 ± 1.87	2.76 ± 1.97	P = 0.232^a
Gravida	Min–Max	1–11	1–13	1–13	P = 0.232^a
History of infertility	No	89 (78.8%)	206 (63.0%)	295 (67.0%)	P = 0.002 ^a
History of infertility	Yes	24 (21.2%)	121 (37.0%)	145 (33.0%)	P = 0.002 ^a
Previous normal vaginal delivery	No	45 (39.8%)	162 (49.4%)	207 (46.9%)	P = 0.079^a
Previous normal vaginal delivery	Yes	68 (60.2%)	166 (50.6%)	234 (53.1%)	P = 0.079^a
Previous cesarean section	No	68 (60.2%)	171 (52.1%)	239 (54.2%)	P = 0.139^a
Previous cesarean section	Yes	45 (39.8%)	157 (47.9%)	202 (45.8%)	P = 0.139^a
Previous dilation and curettage	No	106 (93.8%)	307 (93.6%)	413 (93.7%)	P = 0.938^a
Previous dilation and curettage	Yes	7 (6.2%)	21 (6.4%)	28 (6.3%)	P = 0.938^a
Treatment with progesterone	No	89 (78.8%)	16 (4.9%)	105 (23.8%)	P < 0.001 ^a
Treatment with progesterone	Yes	24 (21.2%)	312 (95.1%)	336 (76.2%)	P < 0.001 ^a
Urinary tract infection	No	104 (92.0%)	286 (87.2%)	390 (88.4%)	P = 0.165^a
Urinary tract infection	Yes	9 (8.0%)	42 (12.8%)	51 (11.6%)	P = 0.165^a
Diabetes	No	112 (99.1%)	321 (97.9%)	433 (98.2%)	P = 0.686^b
Diabetes	Yes	1 (0.9%)	7 (2.1%)	8 (1.8%)	P = 0.686^b
Anemia	No	68 (60.2%)	181 (55.2%)	249 (56.5%)	P = 0.380^a
Anemia	Yes	45 (39.8%)	147 (44.8%)	192 (43.5%)	P = 0.380^a
Hypothyroid	No	113 (100.0%)	325 (99.1%)	438 (99.3%)	P = 0.573^b
Hypothyroid	Yes	0 (0.0%)	3 (0.9%)	3 (0.7%)	P = 0.573^b
Hypertension	No	113 (100.0%)	322 (98.2%)	435 (98.6%)	P = 0.345^b
Hypertension	Yes	0 (0.0%)	6 (1.8%)	6 (1.4%)	P = 0.345^b

Data presented as n (%) prevalence, mean ± SD or min–max.

Statistically significant difference at P < 0.05.

χ²-test or ^bFisher’s exact test.

Body Mass Index (BMI) distribution among participants was notably varied, with significant representation across different BMI categories, yet no statistically significant correlation to bleeding incidence was observed based on BMI (P = 0.893). Age, parity, abortion history, and total number of pregnancies did not significantly correlate with bleeding incidence, suggesting these factors do not independently predict bleeding during pregnancy.

A significant correlation was found between history of infertility and the incidence of vaginal bleeding during pregnancy (P = 0.002), with 37.0% of patients who experienced bleeding reporting a history of infertility, compared with 21.2% who did not (Table 2). However, no statistically significant association was revealed between the incidence of vaginal bleeding during pregnancy and history of normal vaginal deliveries or Cesarean sections (P = 0.079 and 0.139, respectively). The study also found no significant impact of a history of dilation and curettage on the occurrence of bleeding during pregnancy (P = 0.938). A notable finding was the strong association between progesterone treatment and the incidence of bleeding, where progesterone treatment, administered during pregnancy, was found to be significantly associated with a higher incidence of vaginal bleeding (95.1% of patients who experienced bleeding during pregnancy had undergone progesterone treatment versus 4.9% who did not report bleeding; P < 0.001).

No statistically significant associations were found between pre-pregnancy comorbidities, including urinary tract infections, diabetes, anemia, hypothyroidism, or hypertension, and the incidence of bleeding during pregnancy (P = 0.165, 0.686, 0.380, 0.573, and 0.345, respectively). Of note, the majority of participants, regardless of bleeding status, did not present with these conditions (Table 2).

Associated symptoms

Data on pregnancy bleeding, bleeding-associated symptoms and pregnancy complications are summarized in Table 3.

Table 3.

Bleeding associated symptoms and complications in patients with or without bleeding during pregnancy.

Characteristic		Pregnancy bleeding		Total (N = 441)	Statistical significance
Characteristic		No (n = 113)	Yes (n = 328)	Total (N = 441)	Statistical significance
Pain (associated with bleeding)	No	73 (64.6%)	86 (26.2%)	159 (36.1%)	P < 0.001 ^a
Pain (associated with bleeding)	Yes	40 (35.4%)	242 (73.8%)	282 (63.9%)	P < 0.001 ^a
Spotting red	No	113 (100%)	42 (12.8%)	150 (34.0%)	P < 0.001 ^b
Spotting red	Yes	0 (0%)	286 (87.2%)	291 (66.0%)	P < 0.001 ^b
Spotting brownish	No	113 (100%)	39 (11.9%)	146 (33.1%)	P < 0.001 ^a
Spotting brownish	Yes	0 (0%)	289 (88.1%)	295 (66.9%)	P < 0.001 ^a
Clots	No	113 (100%)	272 (82.9%)	383 (86.8%)	P < 0.001 ^b
Clots	Yes	0 (0%)	56 (17.1%)	58 (13.2%)	P < 0.001 ^b
Hematoma at ultrasound	No	109 (96.5%)	281 (85.7%)	390 (88.4%)	P = 0.002 ^b
Hematoma at ultrasound	Yes	4 (3.5%)	47 (14.3%)	51 (11.6%)	P = 0.002 ^b
Hematoma at ultrasound	No	109 (96.5%)	281 (85.7%)	390 (88.4%)	P = 0.019 ^a
	<1 cm	1 (0.9%)	5 (1.5%)	6 (1.4%)
	1 cm	2 (1.8%)	33 (10.1%)	35 (7.9%)
	>1 cm	1 (0.9%)	9 (2.7%)	10 (2.3%)
Gestational diabetes	No	111 (98.2%)	315 (96.0%)	426 (96.6%)	P = 0.374^b
Gestational diabetes	Yes	2 (1.8%)	13 (4.0%)	15 (3.4%)	P = 0.374^b
Pre-eclampsia	No	113 (100%)	319 (97.3%)	432 (98.0%)	P = 0.120^b
Pre-eclampsia	Yes	0 (0.0%)	9 (2.7%)	9 (2.0%)	P = 0.120^b

Data presented as n (%) prevalence.

Statistically significant difference at P < 0.05.

χ²-test or ^bFisher’s exact test.

Statistically significant associations were found between bleeding during pregnancy and the symptoms of pain, spotting, and clot presence (all P < 0.001). Pain was reported significantly more among women with bleeding, indicating its strong association with this condition. Ultrasound revealed hematomas more frequently in women with bleeding, offering critical diagnostic insight. Of those who bled, 14.3% had a hematoma, while only 3.5% of women without bleeding had this finding (P = 0.002). When categorized by size, hematomas of 1 cm were present in 10.1% of women who bled, >1 cm in 2.7%, and <1 cm in 1.5% versus 1.8%, 0.9% and 0.9%, respectively, in those who did not bleed during pregnancy (P = 0.019). No statistically significant association was found between pregnancy bleeding and pre-eclampsia or diabetes.

NICU admissions and their association with bleeding during pregnancy

Analysis of data related to NICU admissions in connection with bleeding during pregnancy is summarized in Table 4. Specifically, a significantly higher incidence of NICU admissions, and a significantly higher incidence of respiratory distress leading to these admissions, was shown in neonates born to mothers who experienced pregnancy bleeding versus those who did not (P = 0.002 and 0.006, respectively).

Table 4.

Association between bleeding during pregnancy and admission to the neonatal intensive care unit (NICU).

Characteristic		Pregnancy bleeding		Total (N = 441)	Statistical significance
Characteristic		No (n = 113)	Yes (n = 328)	Total (N = 441)	Statistical significance
NICU admission	No	104 (92.0%)	259 (79.0%)	363 (82.3%)	P = 0.002 ^a
NICU admission	Yes	9 (8.0%)	69 (21.0%)	78 (17.7%)	P = 0.002 ^a
Cause of NICU admission: bilirubin	No	109 (96.5%)	309 (94.2%)	418 (94.8%)	P = 0.465^b
Cause of NICU admission: bilirubin	Yes	2 (1.8%)	21 (6.4%)	23 (5.2%)	P = 0.465^b
Cause of NICU admission: cardiac	No	113 (100.0%)	325 (99.1%)	438 (99.3%)	P = 0.573^b
Cause of NICU admission: cardiac	Yes	0 (0.0%)	3 (0.9%)	3 (0.7%)	P = 0.573^b
Cause of NICU admission: respiratory distress	No	111 (98.2%)	290 (90.9%)	401 (90.9%)	P = 0.006 ^b
Cause of NICU admission: respiratory distress	Yes	2 (1.8%)	38 (11.6%)	40 (9.1%)	P = 0.006 ^b
Cause of NICU admission: hypoglycemia	No	112 (99.1%)	327 (99.7%)	439 (99.5%)	P = 0.447^b
Cause of NICU admission: hypoglycemia	Yes	1 (0.9%)	1 (0.3%)	2 (0.5%)	P = 0.447^b

Data presented as n (%) prevalence.

Statistically significant difference at P < 0.05.

χ²-test or ^bFisher’s exact test.

Post-natal outcomes associated with bleeding during pregnancy

Data regarding bleeding during pregnancy and post-natal outcomes are summarized in Table 5, with a nuanced relationship found between bleeding during pregnancy and post-natal outcomes. Differences in rates of normal vaginal deliveries, Cesarean sections, and abortions between patients who did or did not experience bleeding during pregnancy did not reach statistical significance (P = 0.064). However, significant increases were noted in post-delivery bleeding and premature labor during the second and third trimesters. Among those who experienced pregnancy bleeding, 25.6% had premature labor in the second trimester, compared with 8.8% % of patients who did not bleed during pregnancy (P < 0.001). In the third trimester, patients who experienced pregnancy bleeding had significantly higher rates of pre-term labor, than those with no bleeding (18.0% versus 2.7%, P < 0.001; Figure 2).

Table 5.

Post-natal outcomes in patients with or without bleeding during pregnancy.

Characteristic		Pregnancy bleeding		Total (N = 441)	Statistical significance
Characteristic		No (n = 113)	Yes (n = 328)	Total (N = 441)	Statistical significance
Obstetric outcome	Normal vaginal delivery	66 (58.4%)	159 (48.5%)	225 (51.0%)	P = 0.064^a
	Cesarean-section	46 (40.7%)	154 (47.0%)	200 (45.4%)
	Abortion	1 (0.9%)	15 (4.6%)	16 (3.6%)
Postpartum hemorrhage	No	106 (93.8%)	278 (84.8%)	384 (87.1%)	P = 0.013 ^a
Postpartum hemorrhage	Yes	7 (6.2%)	50 (15.2%)	57 (12.9%)	P = 0.013 ^a
Anemia post delivery	No	109 (96.5%)	318 (97.0%)	427 (96.8%)	P = 0.761^b
Anemia post delivery	Yes	4 (3.5%)	10 (3.0%)	14 (3.2%)	P = 0.761^b
Dehiscence	No	113 (100.0%)	324 (98.8%)	437 (99.1%)	P = 0.576^b
Dehiscence	Yes	0 (0.0%)	4 (1.2%)	4 (0.9%)	P = 0.576^b
Placenta low laying at ultrasound	No	112 (99.1%)	318 (21.0%)	430 (97.5%)	P = 0.303^b
Placenta low laying at ultrasound	Yes	1 (0.2%)	10 (2.3%)	11 (2.5%)	P = 0.303^b
Placenta previa at ultrasound	No	113 (100.0%)	326 (99.4%)	439 (99.5%)	P = 1.000^b
Placenta previa at ultrasound	Yes	0 (0.0%)	2 (0.6%)	2 (0.5%)	P = 1.000^b
Maternal outcome: premature labor – second trimester	No	103 (91.2%)	244 (74.4%)	347 (78.7%)	P < 0.001 ^a
Maternal outcome: premature labor – second trimester	Yes	10 (8.8%)	84 (25.6%)	94 (21.3%)	P < 0.001 ^a
Maternal outcome: premature labor – third trimester	No	110 (97.3%)	269 (82.0%)	379 (85.9%)	P < 0.001 ^b
Maternal outcome: premature labor – third trimester	Yes	3 (2.7%)	59 (18.0%)	62 (14.1%)	P < 0.001 ^b

Data presented as n (%) prevalence.

Statistically significant difference at P < 0.05.

χ²-test or ^bFisher’s exact test.

Figure 2.

Relationship between bleeding during pregnancy and premature labor in 441 patients (patients with pregnancy bleeding, n = 328; patients without pregnancy bleeding, n = 113).

Discussion

The findings of the present study, coupled with a comprehensive review of the literature, underscore the necessity of an integrated approach in managing bleeding during pregnancy. Such an approach should be finely tailored to address the distinct risks and outcomes observed across diverse patient profiles. The prevalence of bleeding during pregnancy identified in the present study was 74.4% of total participants, a figure that significantly exceeds previously reported rates. This discrepancy suggests potential selection bias or that the present study population represents a uniquely high-risk group.¹⁹ Notably, the prevalence of pregnancy bleeding is most pronounced during the first trimester (67.1% of patients with bleeding in the present study), a period often associated with implantation and other benign causes of bleeding, as corroborated by existing literature.^19–24 However, the present findings reveal a more complex scenario, where bleeding episodes extend into later pregnancy stages. Specifically, 20.1% of bleeding cases occurred during the second trimester and 12.8% occurred during the third trimester. These rates underscore the need to monitor and manage bleeding throughout pregnancy, as later-stage bleeding is often associated with serious complications, such as placental abruption, placenta previa, and preterm labor, thus supporting the evolving understanding of bleeding etiologies as pregnancy progresses.^3–5,9

The timing of miscarriages, primarily before the 13th week, has been shown in recent studies and underscores the importance of early clinical intervention.²⁵ Although miscarriage timing is a relevant factor in the context of vaginal bleeding, this was not within the scope of the present study. Future research should aim to evaluate the association between vaginal bleeding and miscarriage rates, particularly in the first trimester, to better understand these relationships. The peak of bleeding episodes occurring between the 5th and 8th weeks further emphasizes this need.²⁶ The critical role of gestational age and the visualization of embryonic cardiac activity in improving pregnancy outcomes has been shown in previously published studies, with literature suggesting a significant decrease in miscarriage rates upon the detection of such activity.^27,28

The present findings elucidate the relationship between bleeding during pregnancy and various adverse outcomes, which further reinforces some intricacies involved in obstetric care. As shown in previous studies, the visualization of fetal cardiac activity during bleeding episodes notably reduces the risk of miscarriage,²⁹ emphasizing the prognostic value of ultrasound evaluations. Additionally, women who experience bleeding but continue their pregnancy past viability are at an elevated risk of delivering low birth weight infants and facing increased perinatal morbidity and mortality.^30,31

The impacts of light versus heavy bleeding in early pregnancy have been reported,³² with associated consequential risks, such as fetal growth restriction and preterm premature rupture of membranes.²⁶ The stark contrast in premature labor rates between those with and without bleeding episodes in the present study highlights the significance of bleeding as a risk factor for adverse pregnancy outcomes, a finding echoed by multiple studies.^19,33,34

Contrary to expectations, demographic factors, including educational attainment, have shown a nuanced association with bleeding episodes in the present and previous studies.^35,36 This observation suggests that broader socio-economic considerations should inform prenatal care strategies. The findings of the present study revealed no significant associations between vaginal bleeding during pregnancy and factors such as maternal age, parity, abortion history, or total pregnancies. This aligns with existing literature, suggesting that these demographic factors do not consistently correlate with the incidence of vaginal bleeding in pregnancy.³⁷

Interestingly, a lower educational level correlates with a higher incidence of bleeding, hinting at the potential influence of health literacy, access to care, or adherence to prenatal guidelines on health outcomes.^36,38 This correlation is supported by studies from China and Denmark that found an inverse relationship between socio-economic status and spontaneous miscarriages.^38,39

The mean age of participants experiencing bleeding was 28.47 ± 4.83 years, with no statistically significant difference in age-related bleeding incidence. The link between a history of infertility and an increased incidence of bleeding in the present study underscores the potential complications associated with pregnancies conceived through assisted reproductive technologies.^19,40–44

The association between progesterone treatment and bleeding, as observed in the present study, requires nuanced interpretation.^{24,40,45–47} This finding may reflect the symptomatic management use of progesterone rather than a direct causative relationship, aligning with the current understanding of its role in pregnancy. This is consistent with the work of Stephenson et al., who highlighted that women with a history of recurrent pregnancy loss often benefit from progesterone treatment, which may influence bleeding patterns.⁴⁸

No significant association was found between gestational diabetes and bleeding,^32,46,49 nor between pre-eclampsia and bleeding,^46,50–52 indicating a complex interplay between these conditions and bleeding during pregnancy. These insights highlight the multifaceted nature of bleeding during pregnancy, calling for a deeper investigation into these relationships. Symptoms such as pain, spotting, clots, and hematomas, emerged as significant indicators of bleeding risk,⁴⁹ emphasizing the importance of symptom-based surveillance in prenatal care. The association of bleeding with hematomas on ultrasound also underscores the importance of vigilant monitoring for these symptoms as indicators of potential bleeding complications, guiding both clinical management and patient care strategies.

The present study found no significant association between the prevalence of low-lying placenta or placenta previa and vaginal bleeding during pregnancy, consistent with the findings of previous studies,^19,31 underscoring the diagnostic value of ultrasound in managing these cases. Moreover, the observed higher frequency of hematomas in women who bled, in the present and previous studies,^5,31,46 indicates the relevance of ultrasound in clinical decision-making.

The relationship between bleeding during pregnancy and the mode of delivery,⁴⁷ as well as the significant correlation between antepartum bleeding and post-delivery complications, including NICU admissions,^19,25,53 found in the present and previously published studies, highlights the profound impact of bleeding on neonatal outcomes. The increased incidence of respiratory distress as a cause of NICU admission further highlights pregnancy bleeding as a notable risk factor for respiratory conditions in neonates necessitating specialized care, and underscores the critical need for vigilant prenatal monitoring and intervention in such cases. Thus, comprehensive monitoring and management strategies to mitigate the risks to neonatal health outcomes associated with bleeding during pregnancy are urgently required.

Strengths and limitations

The present study is characterized by several strengths that enhance its credibility and the reliability of its findings. First and foremost, the participant pool comprised all patients who visited a private clinic over a duration of 4 years, specifically for consultations related to vaginal bleeding during pregnancy. This comprehensive approach enabled us to establish clear inclusion and exclusion criteria, ensuring a focused and relevant study cohort. Secondly, the study boasts an acceptable sample size, comprising 441 pregnant women. This number allows for a robust statistical analysis, enhancing the generalizability of the results. Thirdly, a thorough assessment was conducted for each patient, including a review of their previous medical and obstetric-gynecological history (such as abortions and uterine surgeries), current gestational data (including screening and analytical values, as well as a history of obstetric complications), and information regarding the delivery and the newborn.

Despite these strengths, the study is not without limitations. A primary constraint is its retrospective nature, which means the analysis was confined to information available in digitized clinical histories, potentially affecting the depth and breadth of the analyzed data. Secondly, the scope of the study was limited to visits to a private clinic, meaning the follow-up of gestation and subsequent analysis of obstetric history were conducted exclusively within this facility. Consequently, data on patients who received prenatal care at different centers is lacking, though this issue was partially mitigated by retrieving some lost data through external monitoring and collecting medical histories from the centers of delivery. Moreover, the present study sample included patients aged 16–47 years, and it is worth noting that pregnancies at age extremities (<18 and >35 years) tend to be associated with an increased risk of miscarriage. In addition, the study included episodes of vaginal bleeding during pregnancy, regardless of gestational age. Nonetheless, it remains important to acknowledge that the outcomes for mothers and newborns may differ from one trimester to another. Indeed, third trimester bleeding is more linked with pathological etiologies, such as placenta previa or accreta spectrum, compared with first-trimester bleeding, which tends to be physiological. Furthermore, most of the studied patients were city residents (91.8%), which does not necessarily represent the whole Lebanese population

Given the high prevalence of first-trimester bleeding observed and its significant potential implications for pregnancy outcomes, there is a compelling case for extending this research. Conducting a prospective study would allow for the identification, establishment, and control of potential risk factors that may contribute to poor gestational outcomes. This future direction could provide invaluable insights into preventing adverse effects associated with early pregnancy bleeding, thereby enhancing maternal and neonatal health

Conclusion

This study affirms established obstetric research findings while probing crucial management and implication questions of pregnancy bleeding. The study calls for enhanced monitoring and specific interventions for symptomatic bleeding or risk factors, such as infertility and low educational attainment. The findings of the present study revealed no significant associations between vaginal bleeding during pregnancy and maternal age, parity, abortion history, or total pregnancies. Nonetheless, the findings suggest a significant relationship between bleeding episodes and a history of infertility or progesterone treatment during pregnancy. Pre-pregnancy comorbidities, including diabetes, hypertension, and hypothyroidism, were not associated with bleeding. However, pregnancy bleeding was found to be associated with increased incidence of post-delivery bleeding, premature labor, and neonatal complications, such as respiratory distress and NICU admissions. From this perspective, the findings underscore the critical need for vigilant monitoring and possibly earlier intervention for pregnancies complicated by bleeding, to mitigate adverse maternal and neonatal outcomes.

Footnotes

Acknowledgement

We would like to extend our sincere thanks to Mr. Hamza Nakib for his invaluable contributions in enhancing the tables and correcting the mistakes in the manuscript.

Author contributions

Maroun Matar: Conceptualization, supervision, data curation, reviewing the manuscript, visualization; validation.

Georges Yared: Conceptualization, supervision, data curation, reviewing the manuscript, visualization; validation.

Christopher Massaad: Conceptualization; investigation; visualization; writing, review and editing; supervision; formal analysis.

Kariman Ghazal: Conceptualization, methodology, data curation, analysis and writing, visualization; validation.

Data availability statement

The data supporting the findings of this study are available upon request from the corresponding author.

Declaration of conflicting interest

The Authors declare that there are no conflicts of interest.

Funding

This research received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors.

ORCID iD

Kariman Ghazal

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