The effect of maternal haematocrit on offspring IQ at 4 and 7 years of age: a secondary analysis.

OBJECTIVE: To determine whether maternal haematocrit during pregnancy is associated with offspring IQ. DESIGN/SETTING/POPULATION: A secondary analysis of the Collaborative Perinatal Project, which enrolled women between 1959 and 1966 at 12 university hospitals in the United States. METHODS: We evaluated the relation between maternal haematocrit and IQ at 4 and 7 years of age. Linear and log-linear regression models were used to adjust for possible confounders. Marginal structural models with stabilised weights were used to account for selection bias due to children lost to follow up. MAIN OUTCOME MEASURES: Offspring IQ at 4 and 7 years of age. RESULTS: Of 35 959 patients, 1521 (4.2%) had moderate anaemia, 13 769 (38.3%) had mild anaemia, 18 227 (50.7%) had a normal haematocrit, and 2442 (6.8%) had a high haematocrit. The mean IQ at 4 and 7 years was significantly lower in the moderate and mild anaemia groups than in the normal haematocrit group (92.3 and 94.7 versus 100.6, respectively, P < 0.01, at 4 years; and 90.2 and 93.4 versus 99.1 at 7 years, P < 0.01). The high haematocrit group had a significantly higher mean IQ (104.5 at 4 years; 103.2 at 7 years) when compared with the normal haematocrit group (P < 0.01). Women with moderate anaemia were more likely to have children with IQ of 70-84 at 4 years (RR 1.22, 95% CI 1.08-1.38) and <70 at 7 years (RR 1.59, 95% CI 1.14-2.23). Women with a high haematocrit were more likely to have children with an IQ ≥120 at 7 years (RR 1.22, 95% CI 1.08-1.39). CONCLUSIONS: Maternal haematocrit is associated with offspring IQ at 4 and 7 years of age. TWEETABLE ABSTRACT: There is a nonlinear relation between maternal haematocrit and offspring IQ at 4 and 7 years of age.

Prolonged latency of preterm prelabour rupture of membranes and neurodevelopmental outcomes: a secondary analysis.

OBJECTIVE: To determine whether prolonged latency after preterm prelabour rupture of membranes (PPROM) is associated with an increased risk for adverse neurodevelopmental outcomes. DESIGN: This is a secondary analysis of the randomised controlled trial of magnesium sulphate for the prevention of cerebral palsy. SETTING: Multicentre trial. POPULATION: A total of 1305 women with PPROM were analysed, 1056 of whom had an interval of <3 weeks between diagnosis and delivery and 249 of whom had an interval of ≥3 weeks between diagnosis and delivery. METHODS: We evaluated whether the time interval between diagnosis of PPROM and delivery was associated with an increased risk for adverse neurodevelopmental outcomes. Latency was analysed as a continuous variable and categorised by weeks of latency. MAIN OUTCOME MEASURES: The primary outcome was motor and mental Bayley scores of <70 at 2 years of age. Secondary outcomes included motor and mental Bayley scores <85 and mean Bayley scores. Logistic regression was used to control for confounding factors. RESULTS: In the univariate analysis, motor and mental Bayley scores of <70 were similar in the <3 weeks (16.8 and 14.4%) and ≥3 weeks (15.3 and 14.1%) groups. In the regression analysis adjusting for confounding factors, PPROM for ≥3 weeks was an independent risk factor for motor (adjusted odds ratio (aOR) 2.12; 95% confidence interval, 95% CI 1.29-3.49) and mental (aOR 1.83, 95% CI 1.13-3.00) Bayley scores of <70. Neonatal sepsis, gestational age at delivery, maternal education, and race were significantly associated with neurodevelopmental outcomes. CONCLUSIONS: Whereas delivery at later gestational age is associated with improved prognosis for many outcomes, prolonged exposure to an intrauterine environment of PPROM is an independent risk factor for adverse neurodevelopmental outcomes. TWEETABLE ABSTRACT: Prolonged PPROM was associated with motor and mental Bayley scores of <70.

Effect of cervical cerclage on rate of cervical shortening.

OBJECTIVE: Although cerclage has been shown to reduce the risk of recurrent preterm birth in a high-risk patient population, the mechanism by which this occurs is not well understood. Our objective was to evaluate whether cerclage affects the rate of cervical shortening taking into account exposure to 17-hydroxyprogesterone and vaginal progesterone. METHODS: This was a retrospective cohort study of women who had serial cervical length measurements due to a history of spontaneous preterm delivery. Demographic data, obstetric history, progesterone administration, delivery information and serial cervical length measurements were collected. The rate of cervical shortening was compared in women with and without cerclage. Subgroup analyses were performed to compare rates of cervical shortening by indication for cerclage (history indicated vs ultrasound indicated) and outcome in the current pregnancy (cerclage vs no cerclage among those who delivered preterm). RESULTS: A total of 414 women were included of whom 32.4% (n = 134) had a cerclage. There was no difference in the rate of cervical shortening between the cerclage (0.8 mm/week) and no-cerclage (1.0 mm/week, P = 0.43) groups. The rates of cervical shortening among history-indicated and ultrasound-indicated cerclage groups were similar (0.9 vs 1.3 mm/week, respectively, P = 0.2). Among patients with a preterm delivery in the index pregnancy, the rates of cervical shortening among those with (1.31 mm/week) and without (1.28 mm/week, P = 0.78) cerclage were also similar. CONCLUSION: Cervical shortening among women with cerclage occurs at a similar rate to that among women without a cerclage, regardless of indication for cerclage or pregnancy outcome.