Maternal proximity to petrochemical industrial parks and risk of premature rupture of membranes

BACKGROUND

Living near petrochemical industries has been reported to increase the risks of adverse birth outcomes, such as low birth weight and preterm delivery. However, evidence regarding the role of petrochemical exposure in pregnancy complications remains limited. This study evaluated the association between maternal proximity to petrochemical industrial parks (PIPs) during pregnancy and the occurrence of premature rupture of membranes (PROM).

METHODS

We performed a population-based 1:3 case-control study by using the 2004-2014 Taiwanese Birth Certificate Database. Birth records reported as stillbirth or bearing congenital anomalies were excluded. Cases were newborns reported to have PROM, whereas controls were randomly sampled from those without any pregnancy complications by matching birth year and urbanization index of the residential township. The proximity to PIPs was evaluated by calculating the distance to the nearest PIP of the maternal residential township during pregnancy. Furthermore, petrochemical exposure opportunity, accounting for monthly prevailing wind direction, was quantified during the entire gestational period. We applied conditional logistic regression models to evaluate the associations.

RESULTS

In total, 29371 PROM cases were reported during the study period, with a corresponding 88113 healthy controls sampled. The results revealed that living within a 3-km radius of PIPs during pregnancy would increase the risk of PROM (odds ratio [OR] = 1.76, 95% CI: 1.66-1.87). Furthermore, compared with the lowest exposed group, those with high petrochemical exposure opportunity had a significantly increased risk of PROM occurrence (OR = 1.69-1.75). The adverse effects remained robust in the subgroup analysis for both term- and preterm-PROM.

CONCLUSIONS

The results of the present work provide evidence that living near PIPs during pregnancy would increase the risk of PROM, and additional studies are warranted to confirm our findings.

Association between prenatal rare earth elements exposure and premature rupture of membranes: Results from a birth cohort study

BACKGROUND

The widespread exploitation and application of rare earth elements (REE) have led to the risk of human exposure and might result in the adverse health effect on pregnant women. However, no epidemiological studies have explored the associations between prenatal REE exposure and premature rupture of membranes (PROM).

OBJECTIVE

We aimed to investigate the associations of maternal urinary REE levels with the risk of PROM.

METHODS

A total of 4897 mother-newborn pairs were recruited from a birth cohort study in Wuhan, China. Urinary concentrations of REE were measured by inductively coupled plasma mass spectrometry (ICP-MS). The associations of prenatal REE exposure with PROM were evaluated using logistic regression models. False discovery rate (FDR) was applied to adjust for multiple testing. Weighted quantile sum (WQS) regression was used to estimate the association of urinary REE mixture with PROM.

RESULTS

With one unit increase (μg/g creatinine) in natural log-transformed urinary REE levels (Ce, Yb, La, Pr, Nd, Eu, Gd, Dy, Ho, Er, Tm), the adjusted ORs (95% CIs) for the PROM were from 1.143 (1.078, 1.211) to 1.317 (1.223, 1.419), and the associations were still observed after FDR adjustment (all P_FDRs < 0.05). The associations were stronger among male infants than female infants. Furthermore, the urinary REE mixture was also associated with the risk of PROM, a quartile increase in the WQS index of REE resulted in ORs (95% CI) for the PROM of 1.494 (1.356, 1.645) in the adjusted model.

CONCLUSIONS

Our findings suggested that prenatal exposure to REE (Ce, Yb, La, Pr, Nd, Eu, Gd, Dy, Ho, Er, and Tm) and REE mixture were associated with the increased risk of PROM. Further studies from different populations are needed to confirm the associations and to explore the mechanisms.

Maternal exposure to ambient fine particulate matter and risk of premature rupture of membranes in Wuhan, Central China: a cohort study

BACKGROUND

The associations between maternal exposure to ambient PM_2.5 during pregnancy and the risk of premature rupture of membranes (PROM) and preterm premature rupture of membranes (PPROM) are controversial. And no relevant study has been conducted in Asia. This study aimed to determine the association between maternal exposure to ambient PM_2.5 during pregnancy and the risk of (P)PROM.

METHODS

A cohort study including all singleton births in a hospital located in Central China from January 2015 through December 2017 was conducted. Multivariable logistic regression models, stratified analysis, generalized additive model, and two-piece-wise linear regression were conducted to evaluate how exposure to ambient PM_2.5 during pregnancy is associated with the risks of PROM and PPROM.

RESULTS

A total of 4364 participants were included in the final analysis, where 11.71 and 2.34% of births were complicated by PROM and PPROM, respectively. The level of PM_2.5 exhibited a degree of seasonal variation, and its median concentrations were 63.7, 59.3, 55.8, and 61.8 μg/m³ for the first trimester, second trimester, third trimester, and the whole duration of pregnancy, respectively. After adjustment for potential confounders, PROM was positively associated with PM_2.5 exposure (per 10 μg/m³) [Odds Ratio (OR) = 1.14, 95% Confidence Interval (CI), 1.02-1.26 for the first trimester; OR = 1.09, 95% CI, 1.00-1.18 for the second trimester; OR = 1.13, 95% CI, 1.03-1.24 for the third trimester; OR = 1.35, 95% CI, 1.12-1.63 for the whole pregnancy]. PPROM had positive relationship with PM_2.5 exposure (per 10 μg/m³) (OR = 1.17, 95% CI, 0.94-1.45 for first trimester; OR = 1.11, 95% CI, 0.92-1.33 for second trimester; OR = 1.19, 95% CI, 0.99-1.44 for third trimester; OR = 1.53, 95% CI, 1.03-2.27 for the whole pregnancy) Positive trends between the acute exposure window (mean concentration of PM_2.5 in the last week and day of pregnancy) and risks of PROM and PPROM were also observed.

CONCLUSIONS

Exposure to ambient PM_2.5 during pregnancy was associated with the risk of PROM and PPROM.

Estimating the acute effects of ambient ozone pollution on the premature rupture of membranes in Xinxiang, China

While increasing evidence suggests that ozone (O₃) exposure is associated with adverse birth outcomes, only one study has focused on its impact on the premature rupture of membranes (PROM). Therefore, we thus examined the effect of O₃ on PROM in Xinxiang, China, using an over-dispersed Poisson generalized additive model. Several confounding factors, including meteorological factors, temporal trends, the day of the week, and public holidays, were considered in the model. We identified a total of 3255 instances of PROM from January 1, 2015 to December 31, 2017, and there was a significant association between the daily maximum 8-h mean concentrations (O_3-8h) and PROM. Each 10 μg/m³ increase in the 3-day average concentration (lag02) of O_3-8h corresponded to an increment in PROM of 5.42% (95% CI: 1.45-9.39%). Although the results of the stratified analyses were insignificant, a few trending results were observed: stronger associations between O₃ and PROM would occur in women with advanced age (≥35) or during the warm season than those in younger women (<35) or during the cool season. Our study indicates that O₃ exposure is an important risk factor of PROM and should be considered in its prevention and control in the study area.

Maternal lead exposure and premature rupture of membranes: a birth cohort study in China

OBJECTIVES

Maternal exposure to lead (Pb) has been suggested to correlate with adverse birth outcomes, but evidence supporting an association between Pb exposure and premature rupture of membranes (PROM) is limited. The aim of our study was to investigate whether maternal Pb exposure was associated with PROM and preterm PROM.

DESIGN

Cross-sectional cohort study.

STUDY POPULATION

The present study involved 7290 pregnant women from the Healthy Baby Cohort in Wuhan, China, during 2012-2014.

MAIN OUTCOME MEASURES

PROM was defined as spontaneous rupture of amniotic membranes before the onset of labour and was determined with a pH ≥6.5 for vaginal fluid. Maternal urinary Pb level was adjusted by creatinine concentration, and its relationship with PROM was analysed by logistic regression.

RESULTS

The IQR of maternal urinary Pb concentrations of the study population was 2.30-5.64 µg/g creatinine with a median of 3.44 µg/g creatinine. Increased risk of PROM was significantly associated with elevated levels of Pb in maternal urine (adjusted OR 1.23, 95% CI 1.0 to 1.47 for the medium tertile; adjusted OR 1.51, 95% CI 1.27 to 1.80 for the highest tertile). The risk of preterm PROM associated with Pb levels was significantly higher when compared with the lowest tertile (adjusted OR 1.24, 95% CI 0.80 to 1.92 for the medium tertile; adjusted OR 1.73, 95% CI 1.15 to 2.60 for the highest tertile). In addition, the relationship between Pb and PROM was more pronounced among primiparous women than multiparous women (p for interaction <0.01).

CONCLUSIONS

Our study found that higher levels of maternal Pb exposure was associated with increased risk of PROM, indicating that exposure to Pb during pregnancy may be an important risk factor for PROM.

Exposure to Ambient Air Pollution and Premature Rupture of Membranes

Premature rupture of membranes (PROM) is a major factor that predisposes women to preterm delivery. Results from previous studies have suggested that there are associations between exposure to air pollution and preterm birth, but evidence of a relationship with PROM is sparse. Modified Community Multiscale Air Quality models were used to estimate mean exposures to particulate matter less than 10 µm or less than 2.5 µm in aerodynamic diameter, nitrogen oxides, carbon monoxide, sulfur dioxide, and ozone among 223,375 singleton deliveries in the Air Quality and Reproductive Health Study (2002-2008). We used log-linear models with generalized estimating equations to estimate adjusted relative risks and 95% confidence intervals for PROM per each interquartile-range increase in pollutants across the whole pregnancy, on the day of delivery, and 5 hours before delivery. Whole-pregnancy exposures to carbon monoxide and sulfur dioxide were associated with an increased risk of PROM (for carbon monoxide, relative risk (RR) = 1.09, 95% confidence interval (CI): 1.04, 1.14; for sulfur dioxide, RR = 1.15, 95% CI: 1.06, 1.25) but not preterm PROM. Ozone exposure increased the risk of PROM on the day of delivery (RR = 1.06, 95% CI: 1.02, 1.09) and 1 day prior (RR = 1.04, 95% CI: 1.01, 1.07). In the 5 hours preceding delivery, there were 3%-7% increases in risk associated with exposure to ozone and particulate matter less than 2.5 µm in aerodynamic diameter and inverse associations with exposure to carbon monoxide and nitrogen oxides. Acute and long-term air pollutant exposures merit further study in relation to PROM.

Air pollution and preterm premature rupture of membranes: a spatiotemporal analysis

Preterm premature rupture of membranes (PROM) is the leading identifiable predisposing factor for preterm birth. Although maternal exposure to air pollution can potentially have an impact on preterm PROM, there is no available evidence on such an impact. In this study, based on 5,555 singleton births occurring in Barcelona, Spain (2002-2005), we investigated the associations of maternal exposure to nitrogen dioxide, nitrogen oxides, and particulate matter with aerodynamic diameters of ≤2.5 µm (PM2.5), 2.5 µm-10 µm, and ≤10 µm and PM2.5 light absorption with preterm PROM and gestational age at the rupture of membranes (ROM). We utilized temporally adjusted land-use regression models to predict pollutant levels at each subject's home address during each week of her pregnancy. We conducted matched (according to the length of exposure) case-control analyses to estimate the preterm PROM risk associated with 1 interquartile-range increase in exposure levels during the entire pregnancy and during the last 3 months prior to ROM. We found an increase in preterm PROM risk of up to 50% (95% confidence interval: 4, 116) and a 1.3-day (95% confidence interval: -1.9, -0.6) reduction in gestational age at ROM associated with PM2.5 absorbance, nitrogen dioxide exposure, and nitrogen oxide exposure during the entire pregnancy and the last 3 months prior to ROM.

Cigarette smoke induces oxidative stress and apoptosis in normal term fetal membranes

Cigarette smoking and bacterial infections are two major risk factors associated with preterm prelabor rupture of membranes (pPROM). We hypothesized that exposure of fetal membranes to cigarette smoke extracts might induce oxidative stress (OS) and fetal membrane apoptosis, culminating in an alternate pathway to that commonly activated by infection. To test this, we characterized the production of prostanoids and biomarkers of apoptosis in normal term human fetal membrane explant cultures. Fetal membrane explants collected at term (from cesarean deliveries, not in labor) were stimulated with cigarette smoke extract (CSE) for 24 h. Two classes of prostanoids, F2-Isoprostane (F2-IsoP), a marker of OS and PGF2α, a classical uterotonin, were measured by gas chromatography/mass spectrometry. Western blot analyses of tissue lysates were performed to quantify the anti-apoptotic protein Bcl2 and actin (as a control). Fetal membrane apoptosis was detected by immunohistochemistry for active caspase 3 and confirmed by TUNEL staining for nuclear fragmentation. CSE exposure resulted in significantly more F2-IsoP production from fetal membranes (242.8 ± 79.3 pg/ml/mg of total membrane protein) compared to unstimulated controls (131.5 ± 53.1 pg/ml/mg; p < 0.0001). By contrast, PGF2α was not different in CSE vs. controls (1083 ± 527 vs. 1136 ± 835 pg/ml/mg of protein; p = 0.80). CSE-exposed tissues demonstrated a dose-dependent decrease in Bcl2 expression and increases in active caspase 3 and nuclear fragmentation in both amnion and chorion cells compared to controls. In summary, fetal membranes exposed to CSE manifest evidence of OS and apoptosis. The differential pattern of prostanoid production observed in this study supports the hypothesis that an alternate non-inflammatory pathway mediated by OS and apoptosis in pPROM may promote proteolysis resulting in membrane weakening and rupture.

Effect of low lead exposure on gestational age, birth weight and premature rupture of the membrane

OBJECTIVE

To find out the effect of prenatal exposure to low lead from cosmetics on gestational age, premature rupture of the membrane and birth weight.

METHODS

The study was carried out in the mountainous Aseer region, Southwest of Saudi Arabia where the air is thought to be clean and free of lead pollution due to the absence of petroleum smelting and other heavy industries. The region is famous as a holiday resort for tourists from Arabia and the gulf countries. All 176 pregnant women included in the study were of singleton pregnancies of gestational age 27 weeks or more who attended the antenatal outpatient clinic of the main maternity hospital. On the day of delivery 4 milliliters of venous blood from each singleton parturient was placed in a heparinized non-silica containing tube and stored at -20 degrees C prior to analysis.

RESULTS

Ninety-four (70.1%) women out of 134 had maternal blood lead concentration < 200 microg/L and only 40 women had > 200 microg/L. The mean difference in gestational age was 10.5 days, showing a non significant difference (P=0.152). Ninety-three women (72.7%) out of a total of 128 who had blood lead concentration <200 microg/L gave birth to infants weighing an average of 2.87 kg while 35 women who had blood lead level > 200 microg/L gave birth to infants weighing an average of 2.99 kg. The mean difference was 0.12 kg which is non-significant (P=0.261). Regarding premature.rupture of the membrane a total of 127 women with maternal blood lead levels above 200 microg/L showed no significant differences (P=0.64). The Chi-square test of the relationship between the birth weight (kg) and the levels of blood lead below 150 microg/L was not significant while the relationship between the birth weight (kg) and the levels of blood lead above 200 microg/L resulted in very slight differences in the values of infants' birth weight.

CONCLUSION

The detected low lead exposures from cosmetics does not produce statistically significant effects on the three pregnancy outcomes; gestational age, premature rupture of the membrane or birth weight. However, the importance of low lead exposure from the 100% lead sulfide eye cosmetic "kohl" is emphasized".

Water disinfection by-products and pre-labor rupture of membranes

The causes of term pre labor rupture of membranes (term PROM) remain poorly defined. The authors conducted a record-based prevalence study to explore a possible relation between disinfection by-products in drinking water and term PROM in an Australian community with spatially variable trihalomethane and nitrate levels. A multilevel statistical model was used to examine the relation between factors operating at the levels of the individual, district, and water distribution zone and the prevalence of PROM at term among 16,229 women in Perth, Western Australia (2002-2004). Adjusted odds ratios for term PROM increased with increasing tertiles of nitrate exposure (moderate exposure: odds ratio = 1.23, 95% confidence interval: 1.03, 1.52; high exposure: odds ratio = 1.47, 95% confidence interval: 1.20, 1.79), but there was no significant relation with exposure to trihalomethanes. This study raises the possibility that water contaminants may promote the development of PROM at term.

Cocaine use and preterm premature rupture of membranes: improvement in neonatal outcome

OBJECTIVE

Our aim was to determine whether cocaine use increases neonatal morbidity in patients with preterm premature rupture of membranes.

STUDY DESIGN

We reviewed records of pregnancies that were complicated with preterm premature rupture of membranes between 24 weeks to 34 weeks of gestation. Clinical characteristics and neonatal outcomes of patients who had positive results for cocaine in the urine were compared with patients with negative test results.

RESULTS

During the study period, 16.1% (85/528 patients) had a positive result in a urine screen for cocaine use. Patients who used cocaine were older and of higher gravidity and parity. When major neonatal morbidities were compared, there was improvement in morbidities that were linked to neonatal infection in patients with positive test results for cocaine, including pneumonia (3.5% vs 11.7%; P =.012) and sepsis (5.9% vs 14.7%; P =.016). Jointly, neonatal outcomes were significantly worse in the negative cocaine group (chi(2) = 5.143; P =.023).

CONCLUSION

The association of preterm premature rupture of membranes with major neonatal morbidity was unexpectedly and significantly weaker in pregnancies complicated by cocaine use.

Fetal effects of cocaine: an updated meta-analysis

BACKGROUND

A very large number of women in the reproductive age group consume cocaine, leading to grave concerns regarding the long term health of millions of children after in utero exposure. The results of controlled studies have been contradictory, leading to confusion, and, possible, misinformation and misperception of teratogenic risk.

OBJECTIVE

To systematically review available data on pregnancy outcome when the mother consumed cocaine.

METHODS

A meta-analysis of all epidemiologic studies based on a priori criteria was conducted. Comparisons of adverse events in subgroups of exposed vs. unexposed children were performed. Analyses were based on several exposure groups: mainly cocaine, cocaine plus polydrug, polydrug but no cocaine, and drug free.

RESULTS

Thirty three studies met our inclusion criteria. For all end points of interest (rates of major malformations, low birth weight, prematurity, placental abruption, premature rupture of membrane [PROM], and mean birth weight, length and head circumference), cocaine-exposed infants had higher risks than children of women not exposed to any drug. However, most of these adverse effects were nullified when cocaine exposed children were compared to children exposed to polydrug but no cocaine. Only the risk of placental abruption and premature rupture of membranes were statistically associated with cocaine use itself.

CONCLUSIONS

Many of the perinatal adverse effects commonly attributed to cocaine may be caused by the multiple confounders that can occur in a cocaine using mother. Only the risk for placental abruption and PROM could be statistically related to cocaine. For other adverse effects, additional studies will be needed to ensure adequate statistical power.

Prednisone and aspirin in women with autoantibodies and unexplained recurrent fetal loss

BACKGROUND

Recurrent fetal loss has been well described in women with antiphospholipid antibodies. Such women also often have other autoantibodies commonly found in patients with systemic lupus erythematosus. Treating them with prednisone and aspirin may reduce the risk of fetal loss.

METHODS

We screened 773 nonpregnant women who had the unexplained loss of at least two fetuses for antinuclear, anti-DNA, antilymphocyte, and anticardiolipin antibodies and for the lupus anticoagulant. Of 385 women with at least one autoantibody, 202 who later became pregnant were randomly assigned in equal numbers to receive either prednisone (0.5 to 0.8 mg per kilogram of body weight per day) and aspirin (100 mg per day) or placebo for the duration of the pregnancy. The women were stratified according to age (18 to 34 years or 35 to 39 years) and the week of gestation at which the previous fetal losses had occurred (< or = 12 or > 12 weeks). The primary outcome measure was a successful pregnancy.

RESULTS

Live infants were born to 66 women in the treatment group (65 percent) and 57 women in the placebo group (56 percent, P=0.19). More infants were born prematurely in the treatment group than in the placebo group (62 percent vs. 12 percent, P<0.001). The major side effects of therapy in the mothers were hypertension (treatment group, 13 percent; placebo group, 5 percent; P=0.05) and diabetes mellitus (15 percent and 5 percent, P=0.02).

CONCLUSIONS

Treating women who have autoantibodies and recurrent fetal loss with prednisone and aspirin is not effective in promoting live birth, and it increases the risk of prematurity.

Preterm rupture of the membranes associated with recent cocaine use

OBJECTIVE

We postulated that recent cocaine use is common among patients with preterm (< 37 weeks) rupture of the membranes and that cocaine users have shorter latency periods before the onset of labor and delivery compared with those without recent cocaine use.

STUDY DESIGN

A urine toxicologic screen was performed on all patients admitted with preterm rupture of the membranes. Patients were managed expectantly, without tocolytics, antibiotics, or steroids.

RESULTS

One hundred three patients were enrolled; 71 had negative screens and 19 were positive for cocaine alone. Cocaine-positive women were significantly older and had more advanced cervical dilatation at admission and a significantly shorter latency period from rupture of membranes to labor and delivery.

CONCLUSION

Preterm rupture of the membranes associated with recent cocaine use is characterized by advanced cervical dilatation at admission and a shorter latency period to labor and delivery.

Prenatal lead exposure in relation to gestational age and birth weight: a review of epidemiologic studies

Although the adverse effect on pregnancy outcomes at high levels of lead exposure in the workplace has been recognized for years, there is uncertainty regarding the impact of exposure at the lower community exposure levels commonly encountered today. This review summarizes the epidemiologic literature and discusses pertinent methodologic issues and possible sources of interstudy variation. The authors conclude that prenatal lead exposure is unlikely to increase the risk of premature membrane rupture but does appear to increase the risk of preterm delivery. Whether prenatal lead exposure decreases gestational age in terms of infants is unclear. Prenatal lead exposure also appears to be associated with reduced birth weight, but results vary in relation to study design and degree of control for confounding. Adjustment for gestational age, a possible confounder of the birth weight-lead exposure association, did not yield clearer results.

Maternal and fetal serum levels of organochlorine compounds in cases of premature rupture of membranes

Blood residue levels of some organochlorine pesticides (DDT and its analogues, lindane, dieldrin, heptachlor epoxide) and polychlorinated biphenyls were measured in maternal and cord blood in 20 cases of premature rupture of fetal membranes at term and in 15 matched controls. No evidence of a possible organochlorine compounds role in the pathogenesis of premature rupture of the membrane was found.

Pregnancy outcome in 98 women exposed to diethylstilbestrol in utero, their mothers, and unexposed siblings

The reproductive capability and labor complications of 98 women exposed to diethylstilbestrol (DES) in utero were compared with those of 3 separate control groups. The controls consisted of 167 age-matched, normal women, 20 siblings not exposed to DES who had achieved pregnancy, and their mothers. Spontaneous abortion, ectopic pregnancy, incompetent cervix, and premature labor occurred significantly more often in the DES-exposed population than in the normal controls. The controls also achieved a higher percentage of desired pregnancies overall; this was statistically significant (89.6 versus 75.0%, P less than .001). When compared with their mothers, however, the DES-exposed population achieved a greater percentage of desired, viable pregnancies (75.6 versus 67.0%, P less than .001). The unexposed siblings of the DES women achieved a higher percentage of desired, viable pregnancies than did their exposed sisters (86.9 versus 73.6%, P = .274), but less than the normal population (86.9 versus 89.6%).

Use of intramuscular 15(S)-15-methyl prostaglandin F2alpha in failed abortions

Forty-five of 49 patients were aborted successfully with 15(S)-15-Me-PGF2alpha after previous techniques to induce abortion had met with failure in 39. Nine patients had spontaneous premature rupture of membranes without onset of labor. The majority of patients aborted within 7 hours following initiation of this method of treatment.