The interaction effect of bacterial vaginosis and periodontal disease on the risk of preterm delivery

The objective of this article is to determine if coexistence of periodontal disease (PD) and bacterial vaginosis (BV) is synergistic on the risk of spontaneous preterm delivery (sPTD). The study design was secondary analysis of a prospective cohort study. Women were screened 6 to 20 weeks gestation for PD and BV. Groups were defined by presence of BV and stratified on PD. The primary outcome was sPTD <37 weeks gestation. Univariable, stratified, and multivariable analyses were performed to estimate the main and interaction effects of BV and PD on sPTD. Of 1453 women screened, 792 (54.5%) were diagnosed with BV. Neither women with BV in the first trimester nor PD was at higher risk of sPTD (risk ratio [RR] for BV 1.1; 95% confidence interval (CI), 0.8-1.5, and RR for PD 0.9; 95% CI, 0.7-1.3). The interaction between BV and PD did not statistically significantly impact the odds of sPTD. Coexistence of PD and BV did not have a synergistic effect on sPTD.     

Predicting preterm delivery and lowering very preterm delivery rate.

The chances and quality of survival depend on gestational age at birth. Why has PTD not decreased during the last decade, in spite of all the known risk factors? Perinatal data bases tend to include biomedical risk factors and are assembled and analysed retrospectively. These data should form the basis for prediction, and risk factors such as stress, anxiety, inflammation (leading to elevated CRH with its role in PTD), short cervix etc, should be added when assessed prospectively. The goal is preconception and early prediction in pregnancy. Only with the implementation of efficient intervention will we lengthen pregnancies and lower the VPTD rate. More articles about the PTD and complications of preterm births should be published in the lay press. There is no room for pessimism: if everybody involved would do just a little in the right direction, the result would be enormous. Constant auditing of interventions is necessary. The most difficult to "cure" and most likely to relapse are stress, anxiety and social factors, and discrimination in obtaining basic health care. Long forgotten lessons of compassion with pregnant women have not yet been acknowledged as proven to change VPTD into PTD, but are available at no cost world wide.     

Association between maternal periodontal disease and preterm delivery and low birth weight

ObjectiveIt has been suggested that periodontal disease is an important risk factor for preterm low birth weight (PLBW). The purpose of this study was to determine the association of maternal periodontitis with low birth weight (LBW) and preterm birth (PB).Materials and MethodsPregnant women (n = 211) aged 22–40 years were enrolled while receiving prenatal care. Dental plaque, probing depth, bleeding on probing, and clinical attachment level were used as criteria to classify three groups: a healthy group (HG; n = 82), a gingivitis group (GG; n = 67), and a periodontitis group (PG; n = 62). At delivery, birth weight was recorded.ResultsMean infant weight at delivery was 3084.9 g. The total incidence of preterm birth and LBW infants was 10.4% and 8.1%, respectively. The incidence of LBW infants was 4.2% for term and 40.9% for preterm gestations. Maternal height was not correlated with infant birth weight (p = 0.245). Significant differences in mean infant birth weight were observed among the HG, GG, and PG groups (p = 0.030). No significant relationship was found between periodontal disease and PB, but the association between periodontal disease and LBW was significant.ConclusionAfter appropriately controlling for confounding variables, our results do not support the hypothesis of an association that was observed in previous studies of maternal periodontal disease and infant PB, but the association between periodontal disease and LBW is significant.     

Adenomyosis and risk of preterm delivery

OBJECTIVE: To evaluate the risk of preterm delivery in patients with adenomyosis. DESIGN: A 1:2 nested case-control study. SETTING: Tertiary-care institution. POPULATION: A base cohort population of 2138 pregnant women who attended routine prenatal check-up between July 1999 and June 2005. METHODS: From this base cohort population, gravid women with singleton pregnancy who delivered prior to the completion of 37 weeks of gestation were identified and formed the study group. Singleton gravid women who had term delivery and who matched with age, body mass index, smoking, and status of previous preterm delivery were recruited concurrently and served as control group. Preterm delivery cases were further divided into spontaneous preterm delivery and preterm premature rupture of membranes (PPROM) cases. MAIN OUTCOME MEASURES: Risk analysis of preterm delivery between gravid women with and without adenomyosis. RESULTS: One-hundred and four preterm delivery case subjects and 208 control subjects were assessed. Overall, gravid women with adenomyosis were associated with significantly increased risk of preterm delivery (adjusted odds ratio 1.96, 95% CI 1.23-4.47, P=0.022). For subgroup analysis, gravid women with adenomyosis had an adjusted 1.84-fold risk of spontaneous preterm delivery (95% CI 1.32-4.31, P=0.012) and an adjusted 1.98-fold risk of PPROM (95% CI 1.39-3.15, P=0.017). CONCLUSIONS: Gravid women with adenomyosis were associated with increased risk of both spontaneous preterm delivery and PPROM. A common pathophysiological pathway may exist in these two disorders. Further in-depth biochemical and molecular studies are necessary to explore this phenomenon.     

Previous induced abortions and the risk of very preterm delivery: results of the EPIPAGE study

OBJECTIVES: To evaluate the risk of very preterm birth (22-32 weeks of gestation) associated with previous induced abortion according to the complications leading to very preterm delivery in singletons. DESIGN: Multicentre, case-control study (the French EPIPAGE study). SETTING: Regionally defined population of births in France. SAMPLE: The sample consisted of 1943 very preterm live-born singletons (< 33 weeks of gestation), 276 moderate preterm live-born singletons (33-34 weeks) and 618 unmatched full-term controls (39-40 weeks). METHODS: Data from the EPIPAGE study were analysed using polytomous logistic regression models to control for social and demographic characteristics, lifestyle habits during pregnancy and obstetric history. The main mechanisms of preterm delivery were classified as gestational hypertension, antepartum haemorrhage, fetal growth restriction, premature rupture of membranes, idiopathic preterm labor and other causes. MAIN OUTCOME MEASURES: Odds ratios for very preterm birth by gestational age and by pregnancy complications leading to preterm delivery associated with a history of induced abortion. RESULTS: Women with a history of induced abortion were at higher risk of very preterm delivery than those with no such history (OR + 1.5, 95% CI 1.1-2.0); the risk was even higher for extremely preterm deliveries (< 28 weeks). The association between previous induced abortion and very preterm delivery varied according to the main complications leading to very preterm delivery. A history of induced abortion was associated with an increased risk of premature rupture of the membranes, antepartum haemorrhage (not in association with hypertension) and idiopathic spontaneous preterm labour that occur at very small gestational ages (< 28 weeks). Conversely, no association was found between induced abortion and very preterm delivery due to hypertension. CONCLUSION: Previous induced abortion was associated with an increased risk of very preterm delivery. The strength of the association increased with decreasing gestational age.     

Primary dysmenorrhea and risk of preterm delivery

Little is known about the mechanism and biochemical pathway of preterm delivery. Some drugs used to treat preterm labor are also useful for the treatment of primary dysmenorrhea. This study attempted to evaluate the association between primary dysmenorrhea and preterm delivery from an epidemiological perspective. A nested case-control study was conducted; 329 singleton preterm delivery cases were investigated, in aggregate and in subgroups (spontaneous preterm labor and preterm premature rupture of membranes). Concurrently, 329 singleton gravid women with term delivery served as controls. Medical charts and records provided information about the maternal history of dysmenorrhea, index pregnancy outcome, and demographic characteristics. Adjusted odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using the multiple logistic regression method. Gravid women with a history of primary dysmenorrhea had no more risk of preterm delivery than those without a history of primary dysmenorrhea (adjusted OR, 1.16; 95% CI, 0.95 to 2.19; p=0.37). However, for subgroup analysis, gravid women with severe primary dysmenorrhea were associated with an adjusted 2.73-fold risk of spontaneous preterm delivery (95% CI, 1.49 to 4.95; p=0.02), and with an adjusted 1.51-fold risk of preterm premature rupture of membranes (95% CI, 0.68 to 3.22; p=0.31). Severe primary dysmenorrhea is associated with an increased risk of spontaneous preterm delivery. A common pathophysiologic pathway may exist between these two disorders. Further in-depth biochemical and molecular studies are necessary to explore this phenomenon.     

Inflammatory bowel disease and preterm delivery

Objective: The present study investigates pregnancy outcome in women with IBD and examines the effect of pregnancy on the severity of IBD. Method: A case-control study comparing deliveries by mothers with IBD between January 1988 and January 2005 was performed. For every birth by a mother with IBD, four births by non-IBD mothers were randomly selected and adjusted for ethnicity and year of delivery. Result: During the study period there were 48 deliveries to patients with Crohn's disease and 79 deliveries to patients with ulcerative colitis. Higher rates of preterm delivery (< 37 weeks) were found among patients with IBD as compared to the controls (odds ratios (OR) = 2.2; 95% confidence interval (CI) = 1.3–3.8). This association remained significant after adjustment for labor induction and multiple gestations, using the Mantel–Haenszel technique (weighted OR = 2.1; 95% CI 1.3–3.5 and weighted OR = 2.0; 95% CI 1.2–3.5; P = 0.012; respectively). In addition, these patients had higher rates of fertility treatments (OR = 2.2; 95% CI = 1.1–4.4). Using a multivariate analysis, controlling for maternal age and fertility treatments, preterm delivery was seen to be significantly associated with IBD (adjusted OR = 2.0; 95% CI = 1.2–3.5). Perinatal outcomes, such as perinatal mortality, low Apgar scores, and congenital malformations, were comparable to the outcomes in the control group. Conclusion: Maternal IBD is an independent risk factor for preterm delivery. IBD is not associated with adverse perinatal outcome.     

Inflammatory bowel disease and preterm delivery

Background

The association between inflammatory bowel disease (IBD) and preterm delivery is controversial. Study size, quality, and design have been inconsistent, making it difficult to assess the relationship between IBD and preterm delivery.

Objective

Utilizing a systematic search of Pubmed for all relevant literature, this review seeks to clarify the correlation between IBD and preterm delivery and to assess the impact of disease activity and medication usage on this outcome.

Results

The available evidence is inadequate to make any robust claims about the association between IBD and preterm delivery. IBD in pregnant women may represent a risk for preterm delivery, and it is probable that IBD activity augments this risk. Many of the medications used to treat IBD also have a correlation with preterm delivery.

Conclusions

While an association between IBD and preterm delivery may exist, further well-designed prospective studies are necessary to determine how the course and management of disease may impact this outcome.     

Placenta previa and the risk of preterm delivery

Objectives. We aimed to quantify the risk of preterm delivery and maternal and neonatal morbidities associated with placenta previa.

Study design. We conducted a retrospective cohort study of singleton births that occurred between 1976 and 2001, examining outcomes including preterm delivery and perinatal complications. Multivariate logistic regression was used to control for potential confounders. Kaplan–Meier survival curves were constructed to compare preterm delivery in pregnancies complicated by previa vs. no previa.

Results. Among the 38 540 women, 230 women had previas (0.6%). Compared to controls, pregnancies with previa were significantly associated with preterm delivery prior to 28 weeks (3.5% vs. 1.3%; p = 0.003), 32 weeks (11.7% vs. 2.5%; p < 0.001), and 34 weeks (16.1% vs. 3.0%; p < 0.001) of gestation. Patients with previa were more likely to be diagnosed with postpartum hemorrhage (59.7% vs. 17.3%; p < 0.001) and to receive a blood transfusion (11.8% vs. 1.1%; p < 0.001). Survival curves demonstrate the risk of preterm delivery at each week and showed an overall higher rate of preterm delivery for patients with a placenta previa.

Conclusions. Placenta previa is associated with maternal and neonatal complications, including preterm delivery and postpartum hemorrhage. These specific outcomes can be used to counsel women with previa.     

Activity restriction and risk of preterm delivery*

Purpose: We sought to determine whether activity restriction (AR) in a cohort of women at high risk for preterm delivery is associated with the risk of preterm delivery.

Materials and methods: This is a secondary analysis of the Maternal-Fetal Medicine Units MFMU’s Preterm Prediction Study; a multicenter prospective cohort study designed to identify risk factors of preterm birth (PTB). The study group consisted of women with a singleton gestation that at their first study visit (23–24 weeks) had at least one of the following criteria: patient reported contractions, severe back pain, a cervical length <15?mm, spotting, protruding membranes, or positive fetal fibronectin. Women were assessed for AR at a 27- to 29-week study visit. Associations between AR and preterm delivery (<37 weeks) were examined through logistic regression models before and after adjustment for confounders.

Results: Of the 1086 women that met the inclusion criteria, 16.5% (n?=?179) delivered preterm. In this cohort, 9.7% (n?=?105) of women were recommended AR, with 37.1% (n?=?39) having a PTB. In the group not recommended AR (n?=?981), 14.3% (n?=?140) delivered preterm.

Conclusion: In this cohort of women at high risk for PTB, activity restriction was associated with an increased risk of PTB. The use of AR in this population should be discouraged.     

Cervical conization and the risk of preterm delivery

The current body of literature concerning cervical conization and its effect on subsequent pregnancy outcome is conflicting. Depending on the type of conization procedure that is examined and the quality of the control group, the results and conclusions vary widely. Because treatment for cervical intraepithelial neoplasia is commonplace among women of reproductive age, it is imperative that practitioners have an understanding of the issues surrounding the treatment. Therefore, this review will summarize the published literature that addresses excisional procedures of the uterine cervix and the risk of preterm delivery in subsequent pregnancies and provide reasonable treatment recommendations for women with cervical abnormalities and a desire for future fertility.     

Vitamin C intake and the risk of preterm delivery

OBJECTIVE: Ascorbic acid deficiency may lead to premature rupture of the membranes. STUDY DESIGN: The study included a prospective cohort of pregnant women, aged >/=16 years, with singleton gestations who received care at one of four prenatal clinics in central North Carolina from 1995 through 1998. Vitamin C intake preconceptionally and during the second trimester was examined for its association with preterm delivery and subsets of preterm labor, premature rupture of the membranes, and medical induction in 2064 women. RESULTS: Women who had total vitamin C intakes of <10th percentile preconceptionally had twice the risk of preterm delivery because of premature rupture of the membranes (relative risk, 2.2; 95% CI, 1.1, 4.5). This risk was attenuated slightly for second-trimester intake (relative risk, 1.7; 95% CI, 0.8, 3.5). The elevated risk of preterm premature rupture of the membranes was greatest for women with a low vitamin C intake during both time periods. CONCLUSION: Because diet and supplement use are modifiable behaviors, corroboration of these findings would suggest a possible intervention strategy.     

Physical activity and the risk of spontaneous preterm delivery

An epidemiologic case-control study exploring possible risk factors for preterm delivery was undertaken at Yale-New Haven Hospital during 1977. The study groups consisted of 175 mothers of singleton preterm infants and 313 mothers of singleton term infants. Analysis of questionnaire responses provided no evidence that employment, housework, child care and leisure-time physical activity during pregnancy increased the risk of preterm delivery. Women who participated in sports or physical fitness exercises during pregnancy were found to have a significantly decreased risk of preterm delivery as compared to those who were not similarly active; this finding suggests that certain forms of moderate physical activity may actually protect against preterm delivery.     

Short interpregnancy interval and risk of spontaneous preterm delivery

OBJECTIVES: Short interpregnancy intervals are related to increased prevalence of adverse perinatal outcomes. However, the reported association with preterm birth might be due to confounding by factors such as previous pregnancy outcomes, socioeconomic level or lifestyles. The objective of this study was to evaluate the effect of short interpregnancy interval on the occurrence of spontaneous preterm delivery. STUDY DESIGN: The prevalence of a short interpregnancy interval, defined as six or less months between a preceding delivery or abortion and the last menstrual period before index pregnancy, was compared between 263 spontaneous preterm (<37 weeks) and 299 term (37-42 weeks) consecutive births. Separate analyses were performed for early (<34 weeks) and late (34-36 weeks) preterm deliveries. Crude and adjusted odds ratios (ORs) and 95% confidence intervals (CI) were calculated using unconditional logistic regression. RESULTS: There was a significant association between short interpregnancy interval and spontaneous early preterm delivery, both crude (OR=3.9; 95% CI: 1.91-8.10) and adjusted for maternal age, school education, previous birth outcomes, antenatal care, smoking habits, body mass index and gestational weight gain (adj(OR)=3.6; 95% CI: 1.41-8.98). No significant effect on spontaneous late preterm delivery was found (crude(OR)=0.8; 95% CI: 0.32-1.83). CONCLUSIONS: This study showed that short interpregnancy intervals significantly increased the risk of early spontaneous preterm birth but no such effect was evident for late preterm deliveries.     

Placenta previa and the risk of preterm delivery.

OBJECTIVES: We aimed to quantify the risk of preterm delivery and maternal and neonatal morbidities associated with placenta previa. STUDY DESIGN: We conducted a retrospective cohort study of singleton births that occurred between 1976 and 2001, examining outcomes including preterm delivery and perinatal complications. Multivariate logistic regression was used to control for potential confounders. Kaplan-Meier survival curves were constructed to compare preterm delivery in pregnancies complicated by previa vs. no previa. RESULTS: Among the 38 540 women, 230 women had previas (0.6%). Compared to controls, pregnancies with previa were significantly associated with preterm delivery prior to 28 weeks (3.5% vs. 1.3%; p = 0.003), 32 weeks (11.7% vs. 2.5%; p < 0.001), and 34 weeks (16.1% vs. 3.0%; p < 0.001) of gestation. Patients with previa were more likely to be diagnosed with postpartum hemorrhage (59.7% vs. 17.3%; p < 0.001) and to receive a blood transfusion (11.8% vs. 1.1%; p < 0.001). Survival curves demonstrate the risk of preterm delivery at each week and showed an overall higher rate of preterm delivery for patients with a placenta previa. CONCLUSIONS: Placenta previa is associated with maternal and neonatal complications, including preterm delivery and postpartum hemorrhage. These specific outcomes can be used to counsel women with previa.     

Adipokinins in pregnancies at risk of preterm delivery

Objective: To compare adipokinins between women experiencing preterm labor (PTL) and prior preterm deliveries (PTD).

Study design: In this prospective observational cohort, 110 women with a singleton <35 weeks at increased risk of PTD were studied. Serum leptin, adiponectin, and resistin were obtained at three times (23–34 weeks, 35–36 weeks, at delivery) and analyzed via enzyme-linked immunosorbent assay. The adipokinins were compared across time and between PTL (n?=?59) and prior PTD (n?=?51) groups using generalized estimated equation models.

Results: There were no differences in leptin, adiponectin, or resistin levels over the three times between the PTL and PTD groups. There was a trend toward higher leptin levels (p?=?0.06 unadjusted analysis, p?=?0.09 adjusted analysis) at 23–34 weeks. When stratified by body mass index (BMI), there were differences in leptin (p?p?=?0.77 for BMI?≥?30) and adiponectin (p?=?0.04 for BMI?p?=?0.09 for BMI?≥?30), but not in resistin over the three times between the PTL and prior PTD groups.

Conclusion: There were no significant differences in adipokinins in women with PTL and a prior PTD. The trends toward higher leptin levels at 23–34 weeks in women with PTL may represent a compensatory response and require further evaluation in the study of treatments for PTL.