The effect of labour induction on the risk of caesarean delivery: using propensity scores to control confounding by indication.

OBJECTIVE: To use propensity score methods to control for confounding by indication in the association between labour induction and caesarean delivery. DESIGN: Cross-sectional analysis of administrative hospital discharge data supplemented by medical record information. SETTING: Fourteen US member hospitals of the National Perinatal Information Center. SAMPLE: A cohort of 166 559 singleton liveborn deliveries in the period 2007-2012. METHODS: We used propensity scores (PSs) to balance 83 covariates between induced and non-induced women, and compared estimates with traditional covariate adjustment. We estimated PSs for labour induction versus expectant management of pregnancy each week from 34 to 42 weeks of gestation. We estimated risk ratios (RRs) for the association between labour induction and primary caesarean delivery from models with no adjustment, traditional adjustment of five covariates, matched PS, and adjustment for continuous PS. MAIN OUTCOME MEASURE: Caesarean delivery in current or subsequent week of gestation. RESULTS: In crude models labour induction increased the risk of caesarean delivery in all weeks (RR 1.06-1.52), excepting 39 weeks of gestation (RR 0.89). After matching on PS, the analysis showed a significantly decreased risk of caesarean delivery with labour induction during weeks 35-39 (RR 0.77-0.92), and a significantly elevated risk at weeks 40 (RR 1.22) and 41 (RR 1.39). Traditional covariate and PS adjustment resulted in RRs between those from crude and PS-matched models. CONCLUSIONS: There is evidence of considerable confounding by indication in the association of labour induction and caesarean delivery, particularly for preterm deliveries. Using PS methods, we found a reduced risk of caesarean delivery with labour induction before 40 weeks of gestation, and an elevated risk for weeks 40-42. TWEETABLE ABSTRACT: With confounding adjustment, labour induction does not increase the risk of caesarean at 34-39 weeks of gestation.

Effects of dalfampridine on multi-dimensional aspects of gait and dexterity in multiple sclerosis among timed walk responders and non-responders.

BACKGROUND: Dalfampridine extended release 10mg tablets (D-ER) have demonstrated improvement in walking for ambulatory persons with multiple sclerosis (pwMS), termed "responders." OBJECTIVE: This study examined the extent additional aspects of gait and dexterity change for patients prescribed D-ER. METHODS: Over 14-weeks, walking endurance, dynamic gait, self-report walking ability and fine and gross dexterity were examined in pwMS prescribed D-ER as a part of routine clinical care. RESULTS: The final results (n=39) validate that a subset of pwMS improve walking speed (Time 25-Foot Walk Test, p<0.0001). Significant improvements in gait and dexterity were observed even among participants who did not improve walking speed. Improvements were evident in gait and dexterity domains including Six Minute Walk Test, p=0.007, Six-Spot Step Test, p<0.0001, Multiple Sclerosis Walking Scale-12, p<0.0001, Nine Hole Peg Test, p<0.0001 dominant and non-dominant sides, and Box and Blocks Test, p=0.005 and 0.002, dominant and non-dominant sides, respectively. CONCLUSIONS: These findings suggest that D-ER may be a potential treatment for gait impairments, beyond walking speed and dexterity in pwMS. Further investigation regarding D-ER response is warranted.

Preterm delivery and risk of subsequent cardiovascular morbidity and type-II diabetes in the mother.

OBJECTIVE: Preterm delivery has been shown to be associated with subsequent maternal cardiovascular morbidity. However, the impact of the severity and recurrence of preterm delivery on the risk of specific cardiovascular events and the metabolic syndrome in the mother, have not been investigated. DESIGN: National registry-based retrospective cohort study. SETTING: Women delivering in Denmark from 1978 to 2007. POPULATION: Women with a first singleton delivery (n = 782 287), and with a first and second singleton delivery (n = 536 419). METHODS: Cox proportional hazard models, with the gestational age stratified into four groups as primary exposure. We made adjustments for maternal age, year of delivery, hypertensive pregnancy disorders, fetal growth deviation, placental abruption and stillbirth. MAIN OUTCOME MEASURES: Subsequent maternal hypertension, ischaemic heart diseases, thromboembolism and type-II diabetes. RESULTS: After a first delivery at 32-36 completed weeks of gestation, the adjusted risk of subsequent type-II diabetes increased 1.89-fold (1.69-2.10) and the risk of thromboembolism increased 1.42-fold (1.24-1.62). Women having a preterm delivery in the first pregnancy and a term delivery in the second had a 1.58-fold (1.34-1.86) increased risk of type-II diabetes and a 1.18-fold (0.96-1.44) increased risk of thromboembolism. Women having two preterm deliveries had a 2.30-fold (1.71-3.10) increased risk of type-II diabetes and a 1.80-fold (1.29-2.50) increased risk of thromboembolism. CONCLUSIONS: Preterm delivery is independent of other pregnancy complications associated with subsequent maternal overt type-II diabetes and thromboembolism. The recurrence of preterm delivery will augment these risks.

Genetic influences on smoking cessation and relapse in pregnant women.

Cigarette smoking during pregnancy continues to be a significant public health concern. Maternal smoking during pregnancy has been associated with low birth weight (<2500 g), fetal growth restriction, placental problems, pre-term delivery and spontaneous abortion. Mothers who smoke during pregnancy are twice as likely to give birth to low birth weight infants, and smoking during pregnancy is estimated to be responsible for 20-30% of all low birth weight infants. Smoking during pregnancy not only affects placental function, thus causing obstetrical complications, but nicotine also crosses the placenta and acts as a neuroteratogen. This in turn, elevates the risk of cognitive and auditory processing deficits, and has also been found to be negatively associated with long-term consequences on offspring behaviour. In addition, smoking has negative long-term health consequences for both mother and child, including respiratory conditions, cancer and cardiovascular problems. This review provides insight into the genetic influences on smoking behaviour in pregnant women. In particular, the roles of genes in the neurotransmitter pathways are highlighted. It also emphasises the need for further research in this area, and provides rationale for the importance of focusing on pregnant women who are highly motivated to quit when researching smoking behaviours in women.

Healthy women's PEF variations with ambient summer concentrations of PM10, PM2.5, SO42-, H+, and O3.

The relationship between ambient air pollution and daily change in peak expiratory flow (PEF) was studied in a sample of 473 nonsmoking women (age 19 to 43 yr) in Virginia over summers 1995- 1996. Daily 24-h averages of particulate matter (PM2.5 and PM10), fine particulate sulfate (SO42-) and strong acid (H+), hourly ozone (O3), and select meteorologic variables (e.g., temperature) were collected at a regional outdoor monitoring site. Subjects took PEF measurements twice daily for a 2-wk period using a standard MiniWright peak flow meter. Concurrent measures for summer periods of 24-h PM2.5 (micrograms/m3) ranged from 3.5 to 59.7; H+ (nmol/m3) from 0 to 250; maximal daily 8-h average O3 (ppb) from 17.0 to 87.6. Morning PEF decrements were significantly associated with H+ and PM2. 5. An increase of 50 etamol/m3 of H+ and 10 micrograms/m3 of PM2.5 related to decreases of 0.89 (95% CI = 0.21 to 1.57) and 0.73 (95% CI = 0.07 to 1.38) L/min in morning PEF, respectively. Ozone was the only exposure related to evening PEF with 5-d cumulative lag exposure showing the greatest effect; 7.65 L/ min (95% CI = 2.25 to 13.0) decrease per 30 ppb O3 increase. Separate physiologic effects were observed for summer ambient concentrations of two different pollutants (PEF decrements related to PM2.5 in morning and O3 in evening) at concentrations below the new U.S. EPA 24-h ambient air quality standard for PM2.5 and 8-h standard for O3.