Risk Factors Of Placenta Previa Research Articles

To Determine the Incidence and Risk Factors Associated with Placenta Previa in a Tertiary Care Hospital of Pakistan

Placenta previa is the condition of pregnancy in which placenta implants in lower uterine segment, partially or completely covering the internal os. This condition may associate with many risk factors. Because with placenta previa pregnancy becomes high risk and fetomaternal morbidities and mortalities are also increased. By knowing the risk factors which are the main causative factors for placenta previa fetomaternal outcome can be optimized The purpose of this study is to find the incidence of placenta previa, and also determine the risk factors for placenta previa. This is descriptive prospective study. This study was done in tertiary care hospital of Pakistan. In this study total deliveries were 5381, total patient with previa were found 325 (6.03%). The risk factors of placenta previa are age more than 35 years (28.92%), smoking (20.16%), multiparity (44%), uterine scar (60.30%), previous evacuation and curettage (24.30%). According to age distribution to mostly patients about 135 out of 325 were found between age group of 36-40 years with percentage of 41.23%. Distribution of patients accrding to gestational age mostly found between age 33-35 weeks with percentage of 54.76 percent amd according to gravidity mostly found between G5–G7 with percentage of 42.46 percent. Aim of the study is to find out the risk factors associated with placenta previa and also determine the incidence of placenta previa in tertiary care hospital of Pakistan.

Association of Overt and Subclinical Hyperthyroidism During Weeks 4-8 with Adverse Pregnancy Outcomes.

Background: Although increasing data suggest that hyperthyroidism is associated with adverse pregnancy outcomes, there are only a few reports with different conclusions on whether the mild transient reduction in thyrotropin (TSH) with or without free thyroxine (FT4) elevation during the early stage of pregnancy also causes adverse pregnancy outcomes. Subjects and Methods: We analyzed data from 3,783 women in this study from August 2011 to December 2013. Participants completed a questionnaire survey. Samples of blood were obtained in the 4th-8th week of pregnancy and their TSH, FT4, thyroid peroxidase antibody, and thyroglobulin antibody were measured. We divided the participants into overt hyperthyroidism group (OHG), subclinical hyperthyroidism group (SHG), and control group based on their blood results and followed up on their pregnancy outcomes. Results: (1) The serum level of FT4 in the SHG was much higher than the control group (p < 0.05). No difference was found in the TSH between the OHG and SHG. The positive rate of autoimmune thyroid antibodies in the OHG (25.6%) was significantly higher than that in the SHG (14.2%) and control group (13.9%) (p < 0.05), whereas there was no difference between the SHG and control group. (2) The SHG had a lower incidence of miscarriage (1.7% vs. 7.2%; OR = 0.218, p = 0.016) than the control group, and the OHG had a higher incidence of placenta previa (3.3% vs. 0.8%; OR = 4.366, p = 0.039) than the control group. (3). We used a binary logistic regression to take other factors into consideration and found that subclinical hyperthyroidism was associated with a lower risk of abortion (OR = 0.206; 95% CI = 0.050-0.840; p = 0.028) but higher risk of preeclampsia (OR = 5.143; 95% CI = 1.463-18.076; p = 0.011) and placental abruption (OR = 4.676; 95% CI = 1.017-21.509; p = 0.048), and overt hyperthyroidism may increase the incidence of placenta previa (OR = 4.193; 95% CI = 1.222-14.382; p = 0.023). Conclusions: Subclinical hyperthyroidism during weeks 4-8 of pregnancy may be associated with the decreased incidence of abortion but might be a risk factor for preeclampsia and placental abruption. Meanwhile, pregnancy with overt hyperthyroidism may be an independent risk factor for placenta previa.

Frequency of Placenta Previa in Multigravida at Tertiary Care Hospital

Background: Placenta previa is a localization of placenta in the lower uterine segment, near or over the internal os. Multigravida is one of the risk factors of placenta previa. The aim of study is to look for current frequency of placenta previa in multigravida, so that further improvement in diagnosis and treatment modalities can be made in order to decrease the morbidity &amp; mortality related to it in this group.Objective: To determine the frequency of various grades of placenta previa in multigravida at a tertiary care center.Methodology: This is a cross sectional study conducted from December 2014 to June 2015 at the department of Gynecology and Obstetrics, Rajshahi Medical College Hospital. A total of 208 patients enrolled in the study with non -probability purposive sampling technique. All pregnant women with singleton pregnancy of 25-35 years of age in their second or more pregnancy with gestational age ≥ 34 weeks were included. Exclusion criteria observed for patients with multifetal pregnancy, previous history of cesarean section, dilatation and curettage, cervical cone biopsy, myomectomy or any pelvic surgery. All pregnant women had trans-abdominal ultrasound. The presence or absence of placenta previa was reported by an experienced sonologist. The data was analyzed using SPSS version 12.Results: Among the total recruited patients, mean age of these multigravidas was 30.1±5.6 years. The mean parity of our population was 4.02±1.2. The gestational age noted was 38±1.4 weeks as mean.. The frequency of placenta previa was 13 (6.3%) and type IV was the most common type.Conclusion: It is concluded from this study that the frequency of placenta previa in patients of multigravida was 6.3% and apart from other risk factors, multigravidity is an independent risk factor for placenta previa.TAJ 2012; 25: 59-63

Placenta previa after prior abortion: a meta-analysis

There is controversy regarding the role of prior abortion on placenta previa in subsequent pregnancies. We conducted an updated, comprehensive meta-analysis of placenta previa after prior abortion. The search was conducted from PubMed, Web of Science and Scopus databases from the database inception to January 31, 2017. The heterogeneity across studies was evaluated by Q-test and I2 statistical test. Publication bias was assessed by Begg's test and Egger's test. Results of odds ratio (OR) estimates with their corresponding 95% confidence intervals (CI) were pooled using random-effects modeling. The literature search included 872 articles up until January 2017 with 2,134,529 participants. Based on OR estimates obtained from case-control and cohort studies, we found a significant association between prior spontaneous abortions and placenta previa (1.77; 95% CI: 1.60, 1.94) and between prior induced abortions and placenta previa (1.36; 95% CI: 1.02, 1.69). The meta-analysis study herein showed that prior abortion is a risk factor for placenta previa.

Determinants of placenta previa: a case-control study

Background: The risk factors of placenta previa differ around the world. This study evaluated risk factors of pregnancies complicated with placenta previa during a 5-year period in a referral center in Hamadan, Iran.&#x0D; Methods: This case control study was conducted in Hamadan city (Hamadan Province of Iran) from April 2013 to March 2017. The cases were women whose deliveries were complicated by placenta previa and the controls were those who delivered without placenta previa. We recruited 130 cases and 130 controls. Multivariate unconditional logistic regression analysis was conducted, and odds ratios (ORs) and 95% confidence intervals (CIs) were calculated.&#x0D; Results: The OR of placenta previa was 4.08 (95% CI= 1.44, 11.58) by maternal age, 4.08 (95% CI =1.44, 11.58) by preterm labor, and 6.64 (95% CI =1.09, 40.45) by prior operations of the uterine cavity, compared to normal deliveries and after adjusting for other variables. Multiparity, prior spontaneous abortions, and prior cesarean sections were not statistically significant risk factors for placenta previa, when adjusted for other variables. &#x0D; Conclusion: Our study suggests that high maternal age and prior operations of the uterine cavity are risk factors for placenta previa.

Risk Analysis of Placenta Previa in Subsequent Pregnancy with History of Cesarean Section: A Case Control Study in Faridpur Medical College Hospital

Placenta previa is a life threatening pregnancy complication where placenta partially or completely covers the internal cervical os causing serious adverse consequence for both mother and baby. History of cesarean delivery is an important risk factor for placenta previa. Which have a increased chance of cesarean hysterectomy and bladder injury because of an associated accrete syndrome. The objective of this study is to analyze the outcome of placenta previa with history of cesarean section. This is a prospective study done in Faridpur Medical College Hospital, Bangladesh from 01.01.2013 up to 31.12.14. Total 18 (study group) patients had undergone cesarean delivery with placenta previa and history of previous cesarean section. Among 18 patients maternal age range was 25- 40, parity 1-4, emergency hysterectomy was done in 11, average blood transfusion 2-8 and other morbidity like urinary bladder injury was 4. So we decided to conduct the study to evaluate the frequency of the placenta previa and morbidity related to number of previous cesarean deliveries.Faridpur Med. Coll. J. Jul 2015;10(2): 52-54

Prevalence and Risk Factors of Placenta Previa in Saudi Arabia and Sudan 2016

Prevalence and Risk Factors of Placenta Previa in Saudi Arabia and Sudan 2016

Risk factors of placenta previa and low set placentation in singleton pregnancy conceived by ART

Risk factors of placenta previa and low set placentation in singleton pregnancy conceived by ART

Факторы риска формирования предлежания плаценты

Факторы риска формирования предлежания плаценты

Risk factors of placenta previa: a population based study and the review of the literature

The aim of our study is to provide a population-based risk factor profile for placenta previa and thereby enable early diagnosis plus the necessary management for this risky group. Methods This research was a retrospective case control study including 25105 pregnancies in the period January 2000- December 2010. The data of 25105 pregnancies were examined on the hospital database. A total of 139 single pregnancies complicated by placenta previa were compared with a randomly selected control group of 1200 single pregnancies. Evaluation was made of risk factors for placenta previa. Results Of the 25105 pregnancies presenting at our clinic during the 10-year period, placenta previa was determined in 139, giving an incidence rate of 0.55%. In the comparison of the two groups; advanced maternal age, multiparity, a history of caesarean section, a history of abortion or uterine curettage, cigarette smoking and male gender were found to be statistically significant as a risk factor for placenta previa. Conclusions The knowledge of the predisposing obstetric factors in respect of the development of placenta previa on a population basis provides the possibility of a careful approach on an individual patient basis.

Correlation of maternal age with placenta previa

Objective: To study the effect of maternal age on incidence of placenta previa. Introduction: Placenta previa is a serious and life threatening obstetric complication where the placenta lies within the lower segment of the uterus, presenting an obstruction to the cervix and to delivery. A trend of increasing placenta previa incidence was observed in the past decade mainly because of an increasing caesarean section rate and advancing maternal age at the time of pregnancy. Methods: This study was a prospective study conducted in a teaching medical college and hospital over a period of two and a half years [2011- 2014]. A detailed history was taken according to our proforma for all pregnant women at or after 32 weeks who attended the hospital in the study period. As per inclusion and exclusion criteria of our study, the study population was selected. All other risk factors for placenta previa except maternal age were excluded. The association between maternal age and placenta previa was analysed. Placenta was located by Transabdominal ultrasound and patients with placenta previa were followed up regularly. Results: Our study showed that women aged ≥35 years or more had increased risk of placenta previa(3.6%) which was statistically significant (p<0.05) by Chi-square test. Conclusion - Advancing maternal age (≥ 35years) appears to increase the risk of placenta previa independent of other risk factors.

P03.09: Management dilemma of complete placenta previa with Breus' mole

Prenatal diagnosis of massive subchorionic thromobohematoma (Breus' mole) is inconsistently reported in the literature. Management of poor prognosis type Breus' mole can be of challenge if combined with potentially life threatening obstetric condition such as placenta previa. We report a 28 year old healthy primigravida of African descent was referred at 19 weeks gestation with ultrasound finding of large placenta. Detailed ultrasound examination revealed posterior placenta away from the cervical os with 4 cm thick, laminated sub-chorionic hematoma extending over the whole length of the placenta “Breus' mole”, severe IUGR fetus with absent end diastolic flow in the umbilical artery. Patient had no history of vaginal bleeding, abdominal pain, trauma and no history of blood disorder. Repeated ultrasound examinations showed enlarged subchorionic hematoma and a complete placenta previa. Given the poor pregnancy outcome, at 28 weeks fetocide using intracardiac KCL was done aiming to devascularise the placenta. Two days later the patient presented to ER with massive antepartum hemorrhage. Emergency Caesarean section was performed. Delivery of a dead male fetus weight 400 gm, the placenta weight 365 gm. Placenta appeared thick, cylindrical with complete circumvallation. A subchorionic hematoma was seen extending from chorionic plate down to decidua basalis. We conclude that despite rare occurrence of Breus' mole; it should be considered a risk factor for placenta previa. There are few case reports indicating less maternal blood loss and decreased morbidity after fetocide through decreased uteroplacental blood flow in cases of complete placenta previa; this does not prove to be the rule with Breus' mole placentas. It's unclear why there would be a tendency to massively bleed after fetocide in cases of placenta previa with Breus' mole. Alternative option of uterine artery embolisation might be considered. Further research on this topic is recommended.

OP16.08: Is twin pregnancy really a risk factor for placenta previa?

OP16.08: Is twin pregnancy really a risk factor for placenta previa?

Previous lower segment caesarean section -a potential risk factor for Placenta Previa

Introduction: Obstetrical hemorrhage continues to be an important cause of maternal mortality, accounting for 15-20% of maternal deaths. Placenta previa is an important cause of both antepartum and post partum haemorrhage. Aim of the Study: To determine the risk of subsequent occurrence of placenta previa in women with history of previous Lower Segment Caesarean Section (LSCS). Materials And Methods: The study was a hospital based prospective study conducted in our medical college and teaching hospital over a period of two years (2011-2013). A detailed history has been taken as per proforma for all pregnant women at or after 32 weeks who attended the hospital in the study period. As per inclusion and exclusion criteria of our study, study population has been selected. The study population was divided into control group [patients with unscarred uterus] and study group [patients with previous LSCS]. Placental location was done by Trans Abdominal Sonography- Ultrasound Sonogram (TAS-USS) and patients with placenta previa were followed up regularly till the time of delivery for pregnancy outcomes. Results: The incidence of placenta previa in patients without previous LSCS was 0.55% and in those patients with previous LSCS was 1.59%. It is statistically significant by Chi Square test X=4.39(P <0.05). Considering the relative risk (RR), in women with previous LSCS scar, the risk for developing placenta previa in subsequent pregnancy is three times more than women without LSCS scar. Conclusion: There is a strong association between previous LSCS and risk of subsequent development of placenta previa. The study also reinforces the importance of advocating vaginal delivery as far as possible and reduces the number of LSCS and future placenta previa. e

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OBJECTIVE: The present study was to find out risk factors of placenta previa among rural Indian women. METHODS: This was a retrospective observational study conducted over two years. 220 women with placenta previa were taken as cases and 440 women without placenta previa were taken as control. RESULTS: Advanced maternal age (OR 2.7; 95% CI: 1.84-3.97), increased parity (OR 1.58; 95% CI: 1.13-2.22), previous abortions (OR 2.25; 95% CI: 1.5-3.35), previous uterine surgery (OR 5.91; 95% CI: 3.56-9.87), uterine anomalies (OR 4.64; 95% CI: 1.41-15.27) and tobacco chewing (OR 3.58; 95% CI: 1.04-12.37) are the potential risk factors. No significant associations have been found with socio economic status, religion, previous history of placenta previa, infertility treatment and sex of the newborn. CONCLUSION: Placenta previa have some identifiable risk factors. Tobacco chewing is a novel potential risk factor.

Risk of placenta praevia is linked to endometrial thickness in a retrospective cohort study of 4537 singleton assisted reproduction technology births.

Is endometrial thickness measured prior to embryo transfer associated with placenta praevia? Following IVF, the risk of placenta praevia is increased 4-fold in women with an endometrial thickness of >12 mm compared with women with an endometrial thickness of <9 mm. Placenta praevia is a serious complication of pregnancy with adverse maternal and neonatal outcomes. Placenta praevia is 2- to 6-fold more likely to occur following IVF treatment but it remains unknown what factors contribute to that increased risk. Retrospective cohort study involving 4007 women who had 4537 singleton assisted reproduction technology (ART) births occurring between January 2006 and June 2012 with no loss to follow-up. The primary outcome measure was the diagnosis of placenta praevia, made by the treating obstetrician on a transvaginal ultrasound in the third trimester. Women who had singleton births following single embryo transfer performed at Monash IVF in Melbourne, Australia were included. Of the 4537 cycles leading to a singleton ART birth, 2951 were stimulated cycles with fresh embryo transfers; 355 were hormone replacement therapy frozen embryo transfers and 1231 were natural cycles with frozen embryo transfers. The dataset was analysed using binary logistic general estimating equations to calculate odds ratios for placenta praevia adjusted (aOR) for known confounders. The study groups did not differ significantly in age, BMI and aetiologies of infertility prior to IVF treatment. When compared with stimulated cycles, placenta praevia was less common in women undergoing natural cycles with frozen embryo transfers (OR 0.44, 95% confidence interval (CI) 0.27-0.70, P < 0.01) but hormone replacement therapy frozen embryo transfer cycles were not associated with a lower risk (OR 0.89, 95% CI 0.48-1.63). After adjusting for confounders, smoking (aOR 2.58, 95% CI 1.07-6.24, P = 0.04, endometriosis (aOR 2.01, 95% CI 1.21-3.33, P < 0.01) and endometrial thickness remained statistically significant as independent risk factors for placenta praevia. Compared with women with an endometrial thickness of <9 mm, women with an endometrial thickness of 9-12 mm had an aOR of 2.02 (95% CI 1.12-3.65, P = 0.02) and women with an endometrial thickness >12 mm had an aOR of 3.74 (95% CI 1.90-7.34, P < 0.01). These differences remained statistically significant after performing a sensitivity analysis limited to women with no previous births. The study is retrospective in nature, not all confounders may have been accounted for and details on previous intrauterine surgery, a known risk factor, were not available. In addition, ultrasound assessments were carried out by several highly trained operators measuring the endometrial thickness, the main independent variable, in a two-dimensional plane and some inter-observer variability may therefore be present. The findings of a higher risk of placenta praevia in patients with endometriosis and in those that smoke are in agreement with the current literature on natural conception. There have so far been no reports of an association between endometrial thickness and placenta praevia after ART. This novel finding warrants further study to elucidate the underlying cause of the association and to assess how to minimize harm to IVF patients and their offspring. The fact that the observed increased risk is not linked to the type of embryo transfer (fresh/frozen) but to the type of endometrial preparation, suggests that the risk of placenta praevia in ART can be reduced by considering an elective frozen embryo transfer in a natural cycle, especially given the growing evidence that this strategy also provides a number of other maternal and neonatal benefits. No funding was required for this study. L.R. has a minority shareholding in Monash IVF and has received unconditional research and educational grants from MSD, Merck-Serono and Ferring. L.R. serves on an advisory board for MSD and Ferring.

Placenta previa and the risk of delivering a small-for-gestational-age newborn.

To evaluate whether there is an association between placenta previa and delivery of a small-for-gestational-age (SGA) newborn and to quantify the contribution of individual risk factors for SGA that are associated with placenta previa stratified by maternal parity. A cross-sectional study using the Finnish Medical Birth Register during 2000-2010. All singleton births (N=596,562) were included; major congenital anomalies were excluded. An association between SGA (less than 2 standard deviations below the mean) and placenta previa was modeled by parity-specific unadjusted and adjusted statistical models. Placenta previa complicated 625 of 249,476 singleton births among nulliparous women (2.50/1,000) and 915 of 347,086 singleton births among multiparous women (2.64/1,000). Among nulliparous women, the most common risk factor for placenta previa was in vitro fertilization; placenta previa was not associated with an increased prevalence of SGA controlling for maternal age, smoking, in vitro fertilization, socioeconomic status, and preeclampsia (adjusted odds ratio [OR] 0.81, 95% confidence interval [CI] 0.57-1.17). Among multiparous women, placenta previa was associated with a twofold increased risk of SGA controlling for maternal age, parity, prior preterm birth, prior caesarean delivery, prior SGA newborn, prior preeclampsia, smoking, in vitro fertilization, socioeconomic status, and preeclampsia (adjusted OR 2.08, 95% CI 1.50-2.89). Furthermore, only one-fourth of the association between SGA and placenta previa could be explained by controlling for risk factors clustering with placenta previa among multiparous women. Placenta previa is associated with impaired fetal growth in multiparous but not nulliparous women. II.

Risk factors of placenta previa and its effects on pregnancy

Objective To explore the risk factors of placenta previa and its effects on pregnancy.Methods We preformed the case-control study basing on the data of 240 maternal with placenta previa and 240 maternal without placenta previa in our hospital from March 2008 to March 2013.Results Among two groups,distributions of age,education level,smoking status,history of childbirth,cesarean section and abortion were statistically significantly different (P ＜ 0.01).The results of the logistic regression analysis showed high age,smoking habit and history of childbirth,cesarean section and abortion were risk factors for placenta previa.Meanwhile,distributions of maternal placenta accreta,placenta accreta,postpartum hemorrhage,premature birth and neonatal asphyxia were statistically significantly different among two groups (P ＜ 0.05).Conclusions Pregnant women with high age,smoking habit and history of childbirth,cesarean section and abortion have a high risk of placenta previa; placenta previa can lead to maternal placenta accreta,placenta accreta,postpartum hemorrhage,premature birth and neonatal asphyxia. Key words: Placenta previa; Risk factors; Pregnancy outcome

536: Prelabor and intrapartum cesarean delivery and subsequent risk of placenta previa

Previous cesarean delivery (CD) is a risk factor for placenta previa. Intrapartum factors that result in thinning of the lower uterine segment may influence uterine repair after CD. We examined the association between CD and subsequent previa while distinguishing between CD prior to onset of labor from intrapartum CD.

Placenta praevia after prior caesarean section: An exploratory case-control study

To identify additional risk factors for placenta praevia in women with prior caesarean section. A retrospective case-control study of 53 cases and 157 controls was performed. Information was obtained from the National Women's database between 2004 and 2009. Cases were defined as women with diagnosed placenta praevia over 20 weeks' gestation and having had one or more prior caesarean sections. Risk factors assessed from the prior caesarean section were (i) type of suture used for hysterotomy closure; (ii) stage of labour; (iii) type of primary surgeon; and (iv) model of funding. Univariate and logistical regression analyses were performed. Use of monofilament suture for hysterotomy closure in prior caesarean section significantly reduced the chance of having placenta praevia in the index pregnancy (adjusted odds ratio 0.26, 95% confidence interval 0.08-0.80), as did prior caesarean being performed in the first stage of labour (aOR 0.36, 95% CI 0.14-0.92). Type of primary surgeon (specialist vs trainee junior doctor), nor model of funding of prior caesarean section (public vs private), was associated with risk of placenta praevia (privately funded specialist aOR 4.75, 95% CI 0.89-25.23 and trainee junior doctor aOR 3.18, 95% CI 0.59-17.28, respectively). A prior caesarean section performed in first stage, and monofilament suture for hysterotomy closure, reduced the chance of having placenta praevia in the index pregnancy.