The influence of uterine fibroids on adverse outcomes in pregnant women: a meta-analysis.

OBJECTIVE: The objective of the meta-analysis was to determine the influence of uterine fibroids on adverse outcomes, with specific emphasis on multiple or large (≥ 5 cm in diameter) fibroids. MATERIALS AND METHODS: We searched PubMed, Embase, Web of Science, ClinicalTrials.gov, China National Knowledge Infrastructure (CNKI), and SinoMed databases for eligible studies that investigated the influence of uterine fibroids on adverse outcomes in pregnancy. The pooled risk ratio (RR) of the variables was estimated with fixed effect or random effect models. RESULTS: Twenty-four studies with 237 509 participants were included. The pooled results showed that fibroids elevated the risk of adverse outcomes, including preterm birth, cesarean delivery, placenta previa, miscarriage, preterm premature rupture of membranes (PPROM), placental abruption, postpartum hemorrhage (PPH), fetal distress, malposition, intrauterine fetal death, low birth weight, breech presentation, and preeclampsia. However, after adjusting for the potential factors, negative effects were only seen for preterm birth, cesarean delivery, placenta previa, placental abruption, PPH, intrauterine fetal death, breech presentation, and preeclampsia. Subgroup analysis showed an association between larger fibroids and significantly elevated risks of breech presentation, PPH, and placenta previa in comparison with small fibroids. Multiple fibroids did not increase the risk of breech presentation, placental abruption, cesarean delivery, PPH, placenta previa, PPROM, preterm birth, and intrauterine growth restriction. Meta-regression analyses indicated that maternal age only affected the relationship between uterine fibroids and preterm birth, and BMI influenced the relationship between uterine fibroids and intrauterine fetal death. Other potential confounding factors had no impact on malposition, fetal distress, PPROM, miscarriage, placenta previa, placental abruption, and PPH. CONCLUSION: The presence of uterine fibroids poses increased risks of adverse pregnancy and obstetric outcomes. Fibroid size influenced the risk of breech presentation, PPH, and placenta previa, while fibroid numbers had no impact on the risk of these outcomes.

Case Report: Abruptio placentae and epileptic seizure after occurrence of perinatal hyperglycaemia in woman with gestational diabetes mellitus and hypertriglyceridemia-induced acute pancreatitis.

Hypertriglyceridemia-induced acute pancreatitis seldom occurs in the second trimester of pregnancy with gestational diabetes mellitus. For these patients, the existing knowledge on concomitant hyperglycemia is not sufficient. We report a case of abruptio placentae and epileptic seizure following perinatal hyperglycaemia in woman with gestational diabetes mellitus and hypertriglyceridemia-induced acute pancreatitis. The occurrence of abruptio placentae and epileptic seizure may be associated with concomitant hyperglycemia, and the epileptic seizure was terminated after she underwent treatment with insulin. We should pay more attention to the adverse effects of perinatal hyperglycemia and continue to give appropriate insulin treatment even if patients have passed the acute phase of hypertriglyceridemia-induced acute pancreatitis.

The role of maternal age on adverse pregnancy outcomes among primiparous women with singleton birth: a retrospective cohort study in urban areas of China.

BACKGROUND: Both young and advanced maternal age pregnancies have strong associations with adverse pregnancy outcomes; however, there is limited understanding of how these associations present in an urban environment in China. This study aimed to analyze the associations between maternal age and pregnancy outcomes among Chinese urban women. METHODS: We performed a population-based study consisting of 60,209 singleton pregnancies of primiparous women whose newborns were delivered after 20 weeks' gestation between January 2012 and December 2015 in urban areas of China. Participants were divided into six groups (19 or younger, 20-24, 25-29, 30-34, 35-39, 40 or older). Pregnancy outcomes include gestational diabetes mellitus (GDM), preeclampsia, placental abruption, placenta previa, premature rupture of membrane (PROM), postpartum hemorrhage, preterm birth, low birthweight, small for gestational age (SGA), large for gestational age (LGA), fetal distress, congenital microtia, and fetal death. Logistic regression models were used to assess the role of maternal age on the risk of adverse pregnancy outcomes with women aged 25-29 years as the reference group. RESULTS: The risks of GDM, preeclampsia, placenta previa, and postpartum hemorrhage were decreased for women at a young maternal age and increased for women with advanced maternal age. Both young and advanced maternal age increased the risk of preterm birth and low birthweight. Young maternal age was also associated with increased risk of SGA (aOR 1.64, 95% CI 1.46-1.83) and fetal death (aOR 2.08, 95% CI 1.35-3.20). Maternal age over 40 years elevated the odds of placental abruption (aOR 3.44, 95% CI 1.47-8.03), LGA (aOR 1.47, 95% CI 1.09-1.98), fetal death (aOR 2.67, 95% CI 1.16-6.14), and congenital microtia (aOR 13.92, 95% CI 3.91-49.57). There were positive linear associations between maternal age and GDM, preeclampsia, placental abruption, placenta previa, PROM, postpartum hemorrhage, preterm birth, LGA and fetal distress (all P for linear trend < .05), and a negative linear association between maternal age and SGA (P for linear trend < .001). The analysis of the associations between maternal age and adverse fetal outcomes showed U-shape for preterm birth, low birth weight, SGA, fetal death and congenital microtia (all P for quadratic trend < .001). CONCLUSIONS: Advanced maternal age predisposes women to adverse obstetric outcomes. Young maternal age manifests a bidirectional effect on adverse pregnancy outcomes. The findings may contribute to improving women's antenatal care and management.

Transfusion and hematologic indices in cases of stillbirth due to placental abruption.

BACKGROUND: Stillbirth because of placental abruption is often associated with maternal hemorrhage and coagulopathy. OBJECTIVE: This study aimed to describe blood product requirements, hematologic indices, and the overall clinical picture of patients experiencing abruption demise. STUDY DESIGN: This retrospective cohort included patients with abruption demise at an urban hospital from 2010 to 2020. Outcome data from patients who delivered stillborn infants ≥500 g or with gestational age of ≥24 weeks were included. Abruption was a clinical diagnosis made by a multidisciplinary stillbirth review committee. The overall number and type of blood products given were analyzed. Patients with a stillbirth who required blood transfusion were compared with those that did not. In addition, the hematologic indices of these 2 populations were analyzed and compared with one another. Finally, the overall clinical characteristics of the 2 populations were analyzed. The analysis of data included chi-square, t test, and logistic and negative binomial regression models. RESULTS: Of 128,252 deliveries, 615 patients (0.48%) experienced a stillbirth, with 76 cases (12%) caused by abruption. Of note, 42 patients (55.2%) required blood transfusion; all received either packed red blood cells or whole blood with a median 3.5 units (2.0-5.5) received. The total units ranged from 1 to 59, with 12 of 42 patients (29%) requiring ≥10 units. Maternal age, gestational age, and mode of delivery were not different, with most (61/76 [80%]) delivering vaginally. Hematocrit level on arrival (odds ratio, 0.80; 95% confidence interval, 0.68-0.91; P=.002) and vaginal bleeding on arrival (odds ratio, 3.73; 95% confidence interval, 1.15-13.40; P=.033) were associated with blood transfusion, as was a diagnosis of preeclampsia (odds ratio, 8.40; 95% confidence interval, 2.49-33.41; P=.001). Those that required a blood transfusion often presented with lower hematologic indices and were more likely to develop disseminated intravascular coagulation (28% vs 0%; P<.001). CONCLUSION: Most patients experiencing stillbirth because of abruption required blood transfusion, with almost 1 in 3 of those patients consuming ≥10 units of blood products. Hematocrit level on arrival, vaginal bleeding, and preeclampsia were all predictors of the need for blood transfusion. Those requiring blood transfusion were more likely to develop disseminated intravascular coagulation. Blood transfusion should be prioritized when abruption demise is suspected.

Impact of maternal late hospital arrival on adverse outcome of offspring affected by placental abruption: A regional multicenter nested case-control study in Japan.

AIMS: To elucidate the influence of the time-intervals between the onset and arrival (TIME 1), onset and delivery (TIME 2), and the decision to deliver and delivery (TIME 3) on severe adverse outcomes of offspring born to mothers complicated by placental abruption outside the hospital. METHODS: This is a multicenter nested case-control study about placental abruption at Fukui Prefecture, a regional area in Japan, through 2013 to 2017. Multiple pregnancy, fetal or neonatal congenital abnormality, and unknown detailed information at onset of placental abruption were excluded. A composite of perinatal death and cerebral palsy or death at 18-36 months of corrected age was defined as the adverse outcome. The relationship between time-intervals and the adverse outcome was analyzed. RESULTS: The 45 subjects for analysis were divided into two groups, including a group with and without adverse outcome (poor, n = 8; and good, n = 37). TIME 1 was longer in the poor group (150 vs. 45 min, p < 0.001). A subgroup analysis targeted to 29 cases with preterm birth at the third trimester indicates that TIME 1 and TIME 2 were longer in the poor group (185 vs. 55 min, p = 0.02; and 211 vs. 125 min, p = 0.03), while TIME 3 was shorter in the poor group (21 vs. 53 min, p = 0.01). CONCLUSIONS: Long time-intervals between onset and arrival or onset and delivery may be correlated with perinatal death or cerebral palsy in surviving infants affected by placental abruption.

Placental abruption and neonatal anemia.

OBJECTIVE: Placental abruption can cause maternal blood loss and maternal anemia. It is less certain whether abruption can cause fetal blood loss and neonatal anemia. STUDY DESIGN: Retrospective multi-hospital 24-month analysis of women with placental abruption and their neonates. RESULTS: Of 55,111 births, 678 (1.2%) had confirmed abruption; 83% of these neonates (564) had one or more hemoglobins recorded in the first day. Four-hundred-seventy (83.3%) had a normal hemoglobin (≥5th% reference interval) while 94 (16.7%) had anemia, relative risk 3.26 (95% CI, 2.66-4.01) vs. >360,000 neonates from previous reference interval reports. The relative risk of severe anemia (<1st% interval) was 4.96 (3.44-7.16). When the obstetrician identified the abruption as "small" or "marginal" the risk of anemia was insignificant. CONCLUSIONS: Most abruptions do not cause neonatal anemia but approximately 16% do. If an abruption is not documented as small, it is important to surveille the neonate for anemia.

Risk factors for placental abruption.

Our case-control study, aiming at identifying the risk factors for placental abruption (PA), looked at variables including maternal age, daily transportation means, folic acid consumption, smoking, past-history of infertility, number of antenatal visits done, presence of pre-eclampsia and umbilical cord insertion. Significant risk factors for PA were frequent transportation by motorbikes, consumption of haematinic preparation not containing folic acid, passive smoking, past-history of infertility, pre-eclampsia and marginal cord insertion. Pregnant women should be counselled about the above-mentioned risk factors.

Identifying risk factors for placental abruption in subsequent pregnancy without a history of placental abruption.

OBJECTIVE: To identify first pregnancy risk factors for placental abruption in subsequent pregnancy. METHODS: In a population-based nested case-control study, cases were defined as women with placental abruption in their second pregnancy, and controls as women without abruption. A total of 43 328 women were included in the study, 0.4% (n = 186) of second pregnancies had placental abruption. Multivariable logistic models were used to study the association between first pregnancy complications and placental abruption in subsequent pregnancy. RESULTS: Having either small for gestational age, preterm delivery, pre-eclampsia or cesarean delivery during first pregnancy were independently associated with increased risk for placental abruption, and the risk was higher with any additional complication (age adjusted odds ratio [aOR] 2.00, 95% confidence interval [CI] 1.46-2.74; aOR 3.61, 95% CI 2.23-5.86; and aOR 3.86, 95% CI 1.56-9.56, for one, two, and three or more complications, respectively). CONCLUSION: First pregnancy may serve as a window of opportunity to identify women at risk for future placental abruption.

Solomon technique vs selective fetoscopic laser photocoagulation for twin-twin transfusion syndrome: systematic review and meta-analysis of maternal and perinatal outcomes.

OBJECTIVE: To ascertain maternal and perinatal outcomes of monochorionic twin pregnancies complicated by twin-twin transfusion syndrome (TTTS) treated with the Solomon technique compared with selective fetoscopic laser photocoagulation (SFLP) of placental anastomoses. METHODS: MEDLINE, EMBASE and The Cochrane Library were searched to identify relevant studies. The outcomes observed were perinatal loss and survival, preterm prelabor rupture of membranes (PPROM), preterm birth (PTB), gestational age (GA) at delivery, interval between laser treatment and delivery, maternal bleeding, septostomy or chorioamniotic separation, placental abruption, twin anemia-polycythemia sequence (TAPS), recurrence of TTTS, neonatal morbidity and neurological morbidity. Random-effects head-to-head meta-analyses were used to analyze the data. Pooled odds ratios (OR) and mean differences (MD) and their 95% CIs were calculated. RESULTS: Nine studies were included in the systematic review. There was generally no difference in the main maternal and pregnancy characteristics between pregnancies treated using the Solomon technique and those treated using SFLP of placental anastomoses. The risks of fetal loss (pooled OR, 0.69 (95% CI, 0.50-0.95); P = 0.023), neonatal death (pooled OR, 0.37 (95% CI, 0.16-0.84); P = 0.018) and perinatal loss (pooled OR, 0.56 (95% CI, 0.38-0.83); P = 0.004) were significantly lower in pregnancies treated using the Solomon technique than in those treated with SFLP. Likewise, pregnancies treated using the Solomon technique had a significantly higher chance of survival of at least one twin (pooled OR, 2.31 (95% CI, 1.03-5.19); P = 0.004) and double survival (pooled OR, 2.18 (95% CI, 1.29-3.70); P = 0.001). There was no difference in the risk of PPROM (P = 0.603), PPROM within 10 days from laser surgery (P = 0.982), PTB (P = 0.207), maternal bleeding (P = 0.219), septostomy or chorioamniotic separation (P = 0.224) or chorioamnionitis (P = 0.135) between the two groups, while the risk of placental abruption was higher in pregnancies treated using the Solomon technique (pooled OR, 2.90 (95% CI, 1.55-5.44); P = 0.001). In the Solomon technique group, pregnancies delivered at a significantly earlier GA than did those treated with SFLP (pooled MD, -0.625 weeks (95% CI, -0.90 to -0.35 weeks); P < 0.001), while there was no difference in the interval between laser treatment and delivery (P = 0.589). The rate of recurrence of TTTS was significantly lower in pregnancies undergoing the Solomon technique (pooled OR, 0.43 (95% CI, 0.22-0.81); P < 0.001), while there was no difference in the risk of TAPS between the two groups (P = 0.792). Finally, there was no difference in the overall risk of neonatal morbidity (P = 0.382) or neurological morbidity (P = 0.247) between the two groups. CONCLUSIONS: Monochorionic twin pregnancies complicated by TTTS undergoing laser treatment using the Solomon technique had a significantly higher survival rate and lower recurrence rate of TTTS but were associated with an increased risk of placental abruption and earlier GA at delivery compared to those treated with SFLP. © 2022 International Society of Ultrasound in Obstetrics and Gynecology.

Placental Abnormalities and Placenta-Related Complications Following In-Vitro Fertilization: Based on National Hospitalized Data in China.

Introduction: Emerging evidence has shown that in-vitro fertilization (IVF) is associated with higher risks of certain placental abnormalities or complications, such as placental abruption, preeclampsia, and preterm birth. However, there is a lack of large population-based analysis focusing on placental abnormalities or complications following IVF treatment. This study aimed to estimate the absolute risk of placental abnormalities or complications during IVF-conceived pregnancy. Methods: We conducted a retrospective cohort study of 16 535 852 singleton pregnancies with delivery outcomes in China between 2013 and 2018, based on the Hospital Quality Monitoring System databases. Main outcomes included placental abnormalities (placenta previa, placental abruption, placenta accrete, and abnormal morphology of placenta) and placenta-related complications (gestational hypertension, preeclampsia, eclampsia, preterm birth, fetal distress, and fetal growth restriction (FGR)). Poisson regression modeling with restricted cubic splines of exact maternal age was used to estimate the absolute risk in both the IVF and non-IVF groups. Results: The IVF group (n = 183 059) was more likely than the non-IVF group (n = 16 352 793) to present placenta previa (aRR: 1.87 [1.83-1.91]), placental abruption (aRR: 1.16 [1.11-1.21]), placenta accrete (aRR: 2.00 [1.96-2.04]), abnormal morphology of placenta (aRR: 2.12 [2.07 to 2.16]), gestational hypertension (aRR: 1.55 [1.51-1.59]), preeclampsia (aRR: 1.54 [1.51-1.57]), preterm birth (aRR: 1.48 [1.46-1.51]), fetal distress (aRR: 1.39 [1.37-1.42]), and FGR (aRR: 1.36 [1.30-1.42]), but no significant difference in eclampsia (aRR: 0.91 [0.80-1.04]) was found. The absolute risk of each outcome with increasing maternal age in both the IVF and non-IVF group presented two patterns: an upward curve showing in placenta previa, placenta accreta, abnormal morphology of placenta, and gestational hypertension; and a J-shape curve showing in placental abruption, preeclampsia, eclampsia, preterm birth, fetal distress, and FGR. Conclusion: IVF is an independent risk factor for placental abnormalities and placental-related complications, and the risk is associated with maternal age. Further research is needed to evaluate the long-term placenta-related chronic diseases of IVF patients and their offspring.

Understanding Etiologic Pathways Through Multiple Sequential Mediators: An Application in Perinatal Epidemiology.

BACKGROUND: Causal mediation analysis facilitates decomposing the total effect into a direct effect and an indirect effect that operates through an intermediate variable. Recent developments in causal mediation analysis have clarified the process of evaluating how-and to what extent-different pathways via multiple causally ordered mediators link the exposure to the outcome. METHODS: Through an application of natural effect models for multiple mediators, we show how placental abruption might affect perinatal mortality using small for gestational age (SGA) birth and preterm delivery as two sequential mediators. We describe methods to disentangle the total effect into the proportions mediated via each of the sequential mediators, when evaluating natural direct and natural indirect effects. RESULTS: Under the assumption that SGA births causally precedes preterm delivery, an analysis of 16.7 million singleton pregnancies is consistent with the hypothesis that abruption exerts powerful effects on perinatal mortality (adjusted risk ratio = 11.9; 95% confidence interval = 11.6, 12.1). The proportions of the estimated total effect mediated through SGA birth and preterm delivery were 2% and 58%, respectively. The proportion unmediated via either SGA or preterm delivery was 41%. CONCLUSIONS: Through an application of causal mediation analysis with sequential mediators, we uncovered new insights into the pathways along which abruption impacts perinatal mortality.

Obstetric outcomes following ovarian hyperstimulation syndrome in IVF - a comparison with uncomplicated fresh and frozen transfer cycles.

BACKGROUND: We aimed to assess the correlation between ovarian hyperstimulation syndrome (OHSS) in the early course of in vitro fertilization (IVF) pregnancies and obstetric outcomes. METHODS: We identified records of patients admitted due to OHSS following IVF treatment at our institution between 2008 and 2020. Cases were included if pregnancy resulted in a live singleton delivery (OHSS group). OHSS cases were matched at a 1:5:5 ratio with live singleton deliveries following IVF with fresh embryo transfer (fresh transfer group) and frozen embryo transfer (FET group), according to maternal age and parity. Computerized files were reviewed, and maternal, obstetric and neonatal outcomes compared. RESULTS: Overall, 44 OHSS cases were matched with 220 fresh transfer and 220 FET pregnancies. Patient demographics were similar between the groups, including body mass index, smoking and comorbidities. Gestational age at delivery, the rate of preterm births, preeclampsia and cesarean delivery were similar between the groups. Placental abruption occurred in 6.8% of OHSS pregnancies, 1.4% of fresh transfer pregnancies and 0.9% of FET pregnancies (p=0.02). On post-hoc analysis, the rate of placental abruption was significantly higher in OHSS pregnancies, compared with the two other groups, and this maintained significance after adjustment for confounders. Birthweights were 3017 ± 483, 3057 ± 545 and 3213 ± 542 grams in the OHSS, fresh transfer and FET groups, respectively (p=0.004), although the rate of small for gestational age neonates was similar between the groups. CONCLUSIONS: OHSS in the early course of IVF pregnancies is associated with an increased risk of placental abruption.

Placental abruption: assessing trends in risk factors over time.

PURPOSE: To evaluate changes in the independent contribution of different risk factors for placental abruption over time. METHODS: In this retrospective nested case-control study, trends of change in ORs for known risk factors for placental abruption occurring in three consecutive 8-year intervals were compared. A univariate assessment of factors associated with placental abruption and two multivariable logistic regression models were constructed to identify independent risk factors for placental abruption. Trends of change in the incidence and specific contribution of various risk factors were compared along the study time-period. RESULTS: During the study period, 295,946 pregnancies met the inclusion criteria; of these, 2170 (0.73%) were complicated with placental abruption. Using logistic regression models, previous cesarean delivery, in vitro fertilization (IVF) pregnancy, hypertensive disorders, polyhydramnios, and inadequate prenatal care were recognized as independent risk factors for placental abruption. While the relative contribution of IVF pregnancy and polyhydramnios to the overall risk for abruption decreased over the course of the study, previous cesarean delivery became a stronger contributor for placental abruption. CONCLUSION: In our study, a change over time in the specific contribution of different risk factors for placental abruption has been demonstrated.

Does placental abruption cause neonatal anemia?

INTRODUCTION: Placental abruption can result in serious perinatal morbidity and mortality. However, it is not clear whether placental abruption could lead to neonatal anemia, as a direct relation has not been described yet. The objective of this study is to investigate whether there is a relation between occurrence of placental abruption and neonatal anemia. MATERIAL AND METHODS: All women with a clinical diagnoses of placental abruption between January 2016 and April 2021 in Amsterdam UMC, from both the VU University Medical Center and Amsterdam Medical Center, were included. Demographic data and delivery outcomes were collected retrospectively using the medical files. The primary outcome was neonatal anemia, defined as hemoglobin levels less than the fifth percentile for gestational age. RESULTS: A total of 65 mothers and 65 neonates were included in our study. Average gestational age was 30 + 5 weeks. Mean hemoglobin level of the neonates at birth was 16.5 g/dl (10.2 mmol/L) with hemoglobin levels comparable to the reference curve. Two neonates (3.6%) were diagnosed with anemia based on their hemoglobin level at birth, and six (9.2%) neonates received a blood transfusion within 24 h after birth. CONCLUSIONS: With this study, we found that the hemoglobin levels of the neonates born after placental abruption are comparable to the reference curve and do not show more neonates than expected below the fifth percentile for gestational age. It remains unclear whether there is fetal blood loss during a placental abruption but our results suggest that at least a big amount of fetal blood is not lost, since we did not found a large number of anemic neonates. Severe neonatal anemia in the case of placental abruption does not need to be expected.

Effects of pre-pregnancy BMI and gestational weight gain on adverse pregnancy outcomes and complications of GDM.

To investigate the effects of pre-pregnancy BMI and gestational weight gain on adverse pregnancy outcomes and complications of gestational diabetes mellitus. 3966 pregnant women were enrolled in this study. Multivariate logistic regression analysis was conducted to estimate the relative risk between pre-pregnancy BMI, gestational weight gain, and adverse pregnancy outcome. Pre-pregnancy BMI was found to be a risk factor for preeclampsia (OR = 1.159), gestational diabetes mellitus (OR = 1.191), gestational hypertension (OR = 1.221), and macrosomia (OR = 1.165). Gestational weight gain was a risk factor for preeclampsia (OR = 1.783), placental abruption (OR = 2.209), and macrosomia (OR = 1.506). Total weight gain during pregnancy cannot be used as a predictor of GDM. Pre-pregnancy BMI is a risk factor for gestational diabetes mellitus complicated with preeclampsia, preterm delivery, gestational hypertension, and macrosomia. Impact statementWhat is already known on this subject? Obesity during pregnancy includes pre-pregnancy obesity and excessive weight gain during pregnancy. Obese pregnant women have a higher risk of pregnancy complications.What do the results of this study add? We focus on the effects of pre-pregnancy BMI on pregnancy outcomes, classified by Asian criteria. Our findings suggest for the first time that excessive weight gain during pregnancy is a risk factor for placental abruption and we specifically point out that total weight gain during pregnancy cannot be used as a predictor of GDM.What are the implications of these findings for clinical practice and/or further research? This study is helpful to monitor the risk of adverse pregnancy outcomes in the Asian population and suggest the risk of pregnancy complications, such as gestational diabetes mellitus and placental abruption.

Defective Placentation Syndromes and Intellectual Disability in the Offspring: Nationwide Cohort and Sibling-Controlled Studies.

We investigated the relationships between syndromic manifestations of defective placentation and the incidence of intellectual disability (ID) in offspring by conducting a population-based cohort study of 1,581,200 nonmalformed, live singleton infants born in Sweden between 1998 and 2014. Exposures were: 1) placental abruption, 2) preterm preeclampsia (<34 weeks of gestation), 3) preeclampsia combined with infant being small for gestational age (SGA) at birth, and 4) spontaneous preterm birth. The outcome was an ID diagnosis after 3 years of age. We estimated hazard ratios (HRs) and 95% confidence intervals (CIs) for each syndrome using Cox regression and robust variances. There were 9,451 children with ID (5.5 per 10,000 child-years). ID incidence rates increased with placental abruption (HR = 2.8, 95% CI: 2.3, 3.5), preterm preeclampsia (HR = 3.7, 95% CI: 2.9, 4.7), preeclampsia combined with SGA (HR = 3.3, 95% CI: 2.6, 4.1), and spontaneous preterm birth (for 32-36 and 22-31 weeks, respectively, HR = 1.6 (95% CI: 1.4, 1.8) and 5.2 (95% CI: 4.3, 6.2)). The same pattern of results was evident in sibling-controlled analyses among 1,043,158 full siblings. The strength of associations increased with ID severity. Preterm birth only partly explained the associations of placental abruption, preeclampsia, or SGA with ID. We conclude that defective placentation is related to increased incidence of ID in the offspring.

The environmental risk factors prior to conception associated with placental abruption: an umbrella review.

BACKGROUND: The present umbrella review evaluated risk factors prior to conception associated with placental abruption based on meta-analyses and systematic reviews. METHODS: We searched PubMed, Scopus, and Web of Science until June 25, 2021. All meta-analyses that had focused on assessing the risk factors associated with placental abruption were included. We calculated summary effect estimates, 95% CI, heterogeneity I2, 95% prediction interval, small-study effects, excess significance biases, and sensitive analysis. The quality of the meta-analyses was evaluated with A Measurement Tool to Assess Systematic Reviews 2 (AMSTAR 2). RESULTS: There was no risk factor in the present umbrella review with the high level of evidence (class I or II). Eight risk factors including maternal asthma (RR 1.29 95% CI 1.14, 1.47), prior cesarean section (RR 1.38, 95% CI 1.35-1.42), cocaine using (RR 4.55, 95% CI 1.78-6.50), endometriosis (OR 1.40, 95% CI 1.12-1.76), chronic hypertension (OR 3.13, 95% CI 2.04-4.80), advanced maternal age (OR 1.44, 95% CI 1.35-1.54), maternal smoking (OR 1.80, 95% CI 1.75-1.85) (RR 1.65, 95% CI 1.51-1.80), and use of assisted reproductive techniques (ART) (OR 1.87, 95% CI 1.70-2.06) were graded as suggestive evidence (class III). The other four risk factors including pre-pregnancy underweight (OR 1.38, 95% CI 1.12-1.70), preeclampsia (OR 1.73, 95% CI 1.47-2.04), uterine leiomyoma (OR 2.63, 95% CI 1.38-3.88), and marijuana use (OR 1.78, 95% CI 1.32-2.40) were graded as risk factors with weak evidence (class IV). CONCLUSION: Maternal asthma, prior cesarean section, cocaine use, endometriosis, chronic hypertension, advanced maternal age, maternal smoking, and use of ART, pre-pregnancy underweight, preeclampsia, uterine leiomyoma, and marijuana use were risk factors associated with placental abruption. Although factors associated with placental abruption have been investigated, the current meta-analytic associations cannot disentangle the complex etiology of placental abruption mainly due to their low quality of evidence.