Maternal and fetal factors which affect fetometry: use of in vitro fertilization and birth register data.

Background: Fetometry dating of gestational age is the gold standard in most developed countries but may have some inborn errors. Dating pregnancies after in vitro fertilization can be used for the evaluation of fetometric studies and for studies of variables which may affect them.

Methods: We compared the actual gestational age of 9543 singleton and 869 twin pregnancies with estimates based on second-trimester fetometry.

Maternal drug use during pregnancy and asthma risk among children.

Background: Maternal use of some drugs, notably paracetamol and drugs for gastroesophageal reflux, has been associated with an increased risk of childhood asthma in the child. We wanted to analyze these associations with consideration to the confounding of maternal asthma.

Methods: Childhood asthma was identified from the Swedish National Prescription Register and maternal drug use during the latter part of pregnancy from antenatal records, computerized in the Swedish Medical Birth Register.

Asthma in Swedish children conceived by in vitro fertilisation.

Objectives: To investigate a proposed association between in vitro fertilisation (IVF) and child asthma.

Design: The risk for asthma after IVF was estimated as ORs using Mantel-Haenszel analysis.

Setting: The Swedish Medical Birth Register.

Association between preterm birth and intrauterine growth retardation and child asthma.

An association between preterm birth and an increased risk of childhood asthma has been demonstrated, but the importance of intrauterine growth retardation on asthma risk is unclear. Using data from Swedish health registers, infant characteristics and childhood asthma were studied. Analyses were made using Mantel-Haenszel methodology with adjustment for year of birth, maternal age, parity, smoking in early pregnancy and maternal body mass index.

Delivery outcome after maternal use of drugs for migraine: a register study in Sweden.

Background: The use of drugs for migraine during pregnancy may have adverse effects on delivery outcome, and warnings exist for such drugs regarding use during pregnancy. Most information in the literature concerns triptans.

Objective: The aim of the study was to describe the delivery outcome when a woman had used drugs for migraine during pregnancy.

Apgar scores at 5 minutes after birth in relation to school performance at 16 years of age.

Objective: To estimate the association between an Apgar score of less than 7 at 5 minutes after birth and long-term cognitive function.

Methods: A linkage between the Swedish Medical Birth Registry and the Swedish School Grade Registry was performed. All singletons born from 1973 to 1986 after 36 6/7 weeks of gestation to Swedish-born women were included.

External review and validation of the Swedish national inpatient register.

Background: The Swedish National Inpatient Register (IPR), also called the Hospital Discharge Register, is a principal source of data for numerous research projects. The IPR is part of the National Patient Register. The Swedish IPR was launched in 1964 (psychiatric diagnoses from 1973) but complete coverage did not begin until 1987.

Antidepressant use during pregnancy: comparison of data obtained from a prescription register and from antenatal care records.

Purpose: To compare interview data on drug use during pregnancy with data identified from a register of prescriptions.

Materials: We compared information from the Swedish Prescribed Drug Register with the Swedish Medical Birth Register on antidepressant use. In order to evaluate the clinical significance of the difference in ascertainment with the two methods, the rate of preterm births among singletons and of neonatal symptoms were studied.

Maternal and child outcome after in vitro fertilization--a review of 25 years of population-based data from Sweden.

Objective: To summarize data on deliveries after in vitro fertilization (IVF) performed in Sweden up to 2006.

Design: Cohort study of women and children, conceived after IVF, with comparisons of deliveries after IVF before and after 1 April 2001.

Setting: Study based on Swedish health registers.

Is there an increased risk for drug treated attention deficit/hyperactivity disorder in children born after in vitro fertilization?

Background: There is mounting evidence that children born after in vitro fertilization (IVF) run an increased risk of neurological complications and notably cerebral palsy. Whether developmental disturbances occur more often than expected is debated.

Aim: To investigate the risk for ADHD in children conceived after IVF.

Cancer risk in children and young adults conceived by in vitro fertilization.

Objectives: Studies conducted so far have found no statistically significant increased risk for cancer among children who are born after in vitro fertilization (IVF).

Methods: We followed 26,692 children who were born after IVF during the years 1982-2005 by using the Swedish Cancer Register and compared the number of children who had cancer and were born after IVF with children who were not conceived by IVF. Adjustment was made for year of birth.

Ocular malformations or poor visual acuity in children born after in vitro fertilization in Sweden.

Purpose: To follow up children born after in vitro fertilization (IVF) with respect to eye malformations and poor visual acuity.

Design: Observational cohort study based on Swedish health registers.

Methods: Congenital eye malformations were studied in 32 091 children born from 1982 through 2007 and severe visual impairment was studied in 24 628 children born from 1985 through 2005 after IVF in Sweden.

Blastocyst versus cleavage stage transfer in in vitro fertilization: differences in neonatal outcome?

Objective: To compare neonatal outcome of blastocyst and cleavage stage embryo transfers after IVF.

Design: Register study.

Setting: Births recorded in the Swedish Medical Birth Register after IVF performed, 2002-2006.

The Swedish personal identity number: possibilities and pitfalls in healthcare and medical research.

Swedish health care and national health registers are dependent on the presence of a unique identifier. This paper describes the Swedish personal identity number (PIN) and explores ethical issues of its use in medical research. A ten-digit-PIN is maintained by the National Tax Board for all individuals that have resided in Sweden since 1947.

Maternal use of antihypertensive drugs in early pregnancy and delivery outcome, notably the presence of congenital heart defects in the infants.

Purpose: To investigate the association between maternal use of antihypertensives in early pregnancy and delivery outcome, notably infant congenital malformations.

Methods: A cohort study of 1,418 women who had used antihypertensive drugs in early pregnancy but had no diabetes diagnosis were identified from the Swedish Medical Birth Register.

Results: There was an excess risk for placental abruption, caesarean section, delivery induction, and post-delivery hemorrhage in women taking hypertensives.

Schizophrenia and offspring's risk for adverse pregnancy outcomes and infant death.

Background: Women with schizophrenia are at increased risk for adverse pregnancy outcomes. It is not known whether offspring born to fathers with schizophrenia also have an increased risk.

Aims: To evaluate paternal and maternal influences on the association between schizophrenia and pregnancy outcomes.

Maternal use of loperamide in early pregnancy and delivery outcome.

Aim: To study delivery outcome including presence of infant congenital malformations after maternal use of loperamide in early pregnancy.

Methods: Using the Swedish Medical Birth Register, women reporting the use of loperamide in early pregnancy were compared with other women for the period July 1, 1995-2004. Odds ratios (OR) or risk ratios (RR) were estimated after adjustment for some variables, which were associated with the use of loperamide (year of delivery, maternal age, parity, smoking, number of previous miscarriages).

Maternal use of selective serotonin re-uptake inhibitors and persistent pulmonary hypertension of the newborn.

In order to evaluate the previously published association between maternal use of selective serotonin re-uptake inhibitors (SSRI) and persistent pulmonary hypertension in the neonate (PPHN), we used data from the Swedish Medical Birth Register for the years 1997-2005. Infants were identified from discharge diagnoses, and maternal exposure to drugs from interviews performed in early pregnancy and from prescriptions from the antenatal care service. Putative confounders were studied: an increased risk for PPHN was indicated for high maternal age, for first parity, for maternal BMI, and possibly for maternal smoking.

Population-based Swedish studies of outcomes after in vitro fertilisation.

Background: Various outcomes have been described during pregnancy and among infants born to women after in vitro fertilisation (IVF) treatments. This mini-review summarises recent population-based Swedish studies about the short- and long-term effects of IVF on the infant and child, and also comments on disturbances of pregnancies and deliveries occurring after IVF.

Methods: Data on women who had IVF treatments and gave birth in Sweden during the period 1982-2001 were collected from all clinics performing IVF.

Use of anti-asthmatic drugs during pregnancy. 3. Congenital malformations in the infants.

Objective: To study the risk for congenital malformations among infants whose mothers used anti-asthmatic drugs during pregnancy.

Materials And Methods: We studied 24,750 infants whose mothers reported the use of anti-asthmatic drugs in early pregnancy. Infants were identified from the Swedish Medical Birth Register where drug use reported at the first maternal health care visit is recorded.

Use of anti-asthmatic drugs during pregnancy. 1. Maternal characteristics, pregnancy and delivery complications.

Objective: To study, in a large cohort, the association between the use of anti-asthmatic drugs during pregnancy and pregnancy complications.

Methods: Using the Swedish Medical Birth Register, we identified 24,369 women who reported the use of anti-asthmatic drugs in early pregnancy and 7778 women who were prescribed such drugs later during pregnancy by antenatal care system centres, during the period July 1, 1995 up to and including 2004. We studied maternal characteristics and pregnancy and delivery complications.