Validation of self-reported data on assisted conception in The Danish National Birth Cohort.
ABSTRACT An increasing number of children are born after assisted conception and in surveillance programmes information on mode of conception is often achieved via maternal self-report. We assessed the validity of self-reported assisted conception in The Danish National Birth Cohort (DNBC), a prospective pregnancy cohort. Here, the term assisted conception refers to IVF, ICSI, ovulation induction and insemination.
We compared self-reported assisted conception in the DNBC to corresponding data from Danish national registers; the IVF Register and Danish Drug Prescription Register, providing method of conception in the entire population. In the DNBC, 101,042 women accepted the invitation in early pregnancy from 1996 to 2002. Our final study population comprised 88,151 DNBC women aged 20 years and older who participated in the first DNBC interview with a pregnancy resulting in a live born child.
In the DNBC, assisted conception was reported with a sensitivity of 83% and positive predictive value of 88%. Misclassification was largely explained by ambiguous phrasing of the DNBC interview question and interview skip patterns. Women with false negative reporting were more often multipara (P < 0.001) and older (P = 0.027 for IVF/ICSI and P = 0.002 for ovulation induction). The risk ratio (RR) for being born preterm in IVF/ICSI children was lower for children identified via the DNBC, RR 3.61 (95% confidence interval (CI) 3.31-3.94), than the IVF Register, RR 4.36 (95% CI 4.02-4.74).
There was a high positive predictive value of self-reported assisted conception in the DNBC, but the structure of the DNBC interview represented a problem and misclassification could introduce bias.
SourceAvailable from: Ulrik Schiøler Kesmodel[Show abstract] [Hide abstract]
ABSTRACT: Objective To study whether fertility treatment or subfertility is associated with long-term growth in the offspring. Design A prospective follow-up study including 1,773 singletons participating in the Lifestyle During Pregnancy Study at the age of 5. Setting Research centers. Patient(s) A total of 3,478 mother-child pairs were sampled from the Danish National Birth Cohort, and 1,773 completed the outcome measurements. A total of 69 children were born after fertility treatment, whereas 132 were born to subfertile parents conceiving spontaneously but after a time to pregnancy of more than 12 months. The remaining 1,572 children were born to parents conceiving spontaneously within 12 months. At the age of 5, the children participated in a follow-up including anthropometric measurements. Information on important covariates with respect to family background, maternal prenatal exposures, perinatal outcomes, and postnatal parental lifestyle characteristics were obtained from the Danish National Birth Cohort, the 5-year follow-up, and Danish health registers. Intervention(s) None. Main Outcome Measure(s) Adjusted mean differences in body weight, height, body mass index (BMI), and head circumference at age 5. Result(s) Compared with spontaneously conceived children born to fertile parents, no systematic differences were observed for body weight, height, BMI, or head circumference at age 5 in children conceived after fertility treatment or to subfertile parents conceiving spontaneously. Conclusion(s) There were no differences in child anthropometrics at 5 years between children conceived after fertility treatment or by subfertile parents compared with that of children born to fertile parents. However, children born after fertility treatment may show catch-up growth during childhood.Fertility and Sterility 10/2014; 102(4). DOI:10.1016/j.fertnstert.2014.06.048 · 4.30 Impact Factor
Epidemiology (Cambridge, Mass.) 09/2014; 25(5):773-5. DOI:10.1097/EDE.0000000000000153 · 6.18 Impact Factor
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ABSTRACT: With cesarean section rates increasing worldwide, clarity regarding negative effects is essential. This study aimed to investigate the rate of subsequent stillbirth, miscarriage, and ectopic pregnancy following primary cesarean section, controlling for confounding by indication.PLoS Medicine 07/2014; 11(7):e1001670. DOI:10.1371/journal.pmed.1001670 · 14.00 Impact Factor