Prevalence of Co-occurring Medical and Behavioral Conditions/Symptoms Among 4- and 8-Year-Old Children with Autism Spectrum Disorder in Selected Areas of the United States in 2010.

We compared the prevalence of various medical and behavioral co-occurring conditions/symptoms between 4- and 8-year-olds with autism spectrum disorder (ASD) from five sites in the Autism and Developmental Disabilities Monitoring Network during the 2010 survey year, accounting for sociodemographic differences. Over 95% of children had at least one co-occurring condition/symptom. Overall, the prevalence was higher in 8- than 4-year-olds for 67% of co-occurring conditions/symptoms examined. Further, our data suggested that co-occurring conditions/symptoms increased or decreased the age at which children were first evaluated for ASD. Similarly, among the 8-year-olds, the prevalence of most co-occurring conditions/symptoms was higher in children with a previous ASD diagnosis documented in their records. These findings are informative for understanding and screening co-occurring conditions/symptoms in ASD.

Brief Report: Estimated Prevalence of a Community Diagnosis of Autism Spectrum Disorder by Age 4 Years in Children from Selected Areas in the United States in 2010: Evaluation of Birth Cohort Effects.

We compared early-diagnosed autism spectrum disorder (ASD) (defined as diagnosis by age 4 years) between the 2002 and 2006 birth cohorts, in five sites of the Autism and Developmental Disabilities Monitoring Network. In the 2002 cohort, the prevalence/1000 of early-diagnosed ASD was half the 8-year-old prevalence (7.2 vs. 14.7, prevalence ratio [PR] 0.5 [0.4-0.6]). Overall, the prevalence of early-diagnosed ASD did not differ between birth cohorts (PR 1.1 [0.9-1.3]). However, in three sites with complete case ascertainment, the prevalence of early-diagnosed ASD was higher for those born in 2006 versus 2002 (PR 1.3 [1.1-1.5]), suggesting possible improvement in early identification. The lack of change in two sites may reflect less complete case ascertainment. Studies in more recent cohorts are needed.

Maternal prepregnancy weight status and associations with children's development and disabilities at kindergarten.

OBJECTIVE: Obesity is prevalent among women of reproductive age, and developmental disabilities in children continue to increase. We examined associations between mother's prepregnancy body mass index (BMI) and physical and developmental disabilities, and objective measures of reading and math skills and fine and gross motor function in children. METHODS: We used the Early Childhood Longitudinal Study-Birth Cohort (ECLS-B; n=5200), a cohort of children born in 2001 and followed until kindergarten. Children were classified according to maternal prepregnancy BMI (in kg per m(2)): underweight (BMI <18.5), normal weight (BMI 18.5-24.9), overweight (BMI 25.0-29.9), obese class I (BMI 30.0-34.9) and obese class II/III (BMI ≥ 35.0). Parent reports of doctor-diagnosed disabilities were collected up to kindergarten and classified as learning and behavioral or physical. Children's reading and math and fine and gross motor function were assessed at kindergarten according to standardized tests. Linear and modified logistic regression models were adjusted for maternal sociodemographic variables, family enrichment variables, and children's sex, age and year of kindergarten entry. Additional adjustment for current child BMI was performed in separate models. All data are weighted to be nationally representative of the children born in 2001. RESULTS: Compared with children of normal-weight mothers, children born to obese class II/III mothers had an increased risk of learning or behavioral (risk ratio 1.67; 95% confidence interval 1.27, 2.21)), but not physical disabilities (risk ratio 0.57; 95% confidence interval 0.27, 1.22). Gross (P<0.001), but not fine (P=0.06) motor function was significantly associated with maternal BMI, but gross motor function was attenuated after adjustment for current child BMI (P=0.05). Children's reading scores (P=0.01) but not math scores (P=0.11) were significantly associated with maternal BMI. CONCLUSIONS: In this nationally representative US cohort, children born to severely obese mothers had an increased risk for diagnosed learning and behavioral but not physical disabilities by kindergarten.

Associations between maternal prepregnancy body mass index and child neurodevelopment at 2 years of age.

OBJECTIVE: Both underweight and obese mothers have an increased risk for adverse offspring outcomes. Few studies have examined the association between prepregnancy body mass index (BMI) and children's neurodevelopment. SUBJECTS: We used data from the nationally representative Early Childhood Longitudinal Study-Birth Cohort (ECLS-B; n=6850). Children were classified according to their mother's prepregnancy BMI (kg m(-2)) status: underweight (BMI <18.5), normal weight (BMI 18.5-24.9), overweight (BMI 25.0-29.9), obese class I (BMI 30.0-34.9), and obese class II and III (BMI ≥35.0). Children's age-adjusted mental development index (MDI) and psychomotor development index (PDI) T-scores (mean 50, s.d. 10) were obtained using a validated shortened version of the Bayley Scales of Infant Development-II at approximately 2 years of age. While adjusting for sociodemographics, we estimated the average MDI and PDI scores or the risk of delayed (<-1 s.d. vs >1 s.d.) mental or motor development, relative to children of normal weight mothers. RESULTS: Compared with children of normal weight mothers, MDI scores were lower among children of mothers of all other prepregnancy BMI categories, with the greatest adjusted difference among children of class II and III obese mothers (-2.13 (95% CI -3.32, -0.93)). The adjusted risk of delayed mental development was increased among children of underweight (risk ratio (RR) 1.36 (95% CI 1.04, 1.78)) and class II and III obese (RR 1.38 (95% CI 1.03, 1.84)) mothers. Children's PDI scores or motor delay did not differ by maternal prepregnancy BMI. CONCLUSION: In this nationally representative sample of 2-year-old US children, low and very-high maternal prepregnancy BMI were associated with increased risk of delayed mental development but not motor development.

Risk of autism spectrum disorders in children born after assisted conception: a population-based follow-up study.

OBJECTIVES: To assess the risk of autism spectrum disorders (ASD) in children born after assisted conception compared with children born after natural conception. DESIGN: Population-based follow-up study. SETTING: All children born alive in Denmark 1995-2003. PARTICIPANTS: 588,967 children born in Denmark from January 1995 to December 2003. Assisted conception was defined as in vitro fertilisation (IVF) with or without intracytoplasmic sperm injection and ovulation induction (OI) with or without subsequent insemination. Children exposed to IVF or OI were identified in the IVF Register and in the Danish Drug Prescription Register. MAIN OUTCOME MEASURES: A diagnosis of ASD in the Danish Psychiatric Central Register. RESULTS: 33,139 (5.6%) of all children born in Denmark in 1995-2003 resulted from assisted conception, 225 of whom (0.68%) had a diagnosis of ASD. Of the 555,828 children born in this period after natural conception, 3394 (0.61%) had a diagnosis of ASD. The follow-up time was 4-13 years (median 9 years). In crude analyses, children born after assisted conception had an increased risk of a diagnosis of ASD: crude hazard rate ratio (HRR) 1.25 (95% CI 1.09 to 1.43). In analyses adjusting for maternal age, educational level, parity, smoking, birth weight and multiplicity, the risk disappeared: adjusted HRR 1.13. (95% CI 0.97 to 1.31). However, subgroup analyses that suggest possible associations in women who received follicle stimulating hormone indicate the need for further study. DISCUSSION: This population-based follow-up study found no risk of ASD in children born after assisted conception.

Use of clomiphene citrate and birth defects, National Birth Defects Prevention Study, 1997-2005.

BACKGROUND: Clomiphene citrate (CC) is the first line drug for subfertility treatment. Studies assessing the association between CC and birth defects have been inconclusive. METHODS: We used data from the National Birth Defects Prevention Study, a population-based, multi-site case-control study of major birth defects. Women from 10 US regions with deliveries affected by at least one of >30 birth defects (cases) and mothers of live born infants without a major birth defect (controls) who delivered October 1997-December 2005 were interviewed. The exposure of interest was reported CC use in the period from 2 months before conception through the first month of pregnancy. Women who conceived using assisted reproductive technology were excluded. Thirty-six birth defect categories with at least three exposed cases were studied. Multiple logistic regression was used to control for potential confounders. RESULTS: CC use was reported by 1.4% of control mothers (94/6500). Among 36 case-groups assessed, increased adjusted odds ratios (aOR) were found [all: aOR, 95% confidence interval (CI)] for anencephaly (2.3, 1.1-4.7), Dandy-Walker malformation (4.4, 1.7-11.6), septal heart defects (1.6, 1.1-2.2), muscular ventricular septal defect (4.9, 1.4-16.8), coarctation of aorta (1.8, 1.1-3.0), esophageal atresia (2.3, 1.3-4.0), cloacal exstrophy (5.4, 1.6-19.3), craniosynostosis (1.9, 1.2-3.0) and omphalocele (2.2, 1.1-4.5). CONCLUSIONS: Several associations between CC use and birth defects were observed. However, because of the small number of cases, inconsistency of some findings with previous reports, and the fact that we cannot assess the CC effect separately from that of the subfertility, these associations should be interpreted cautiously.

Multiplicity and early gestational age contribute to an increased risk of cerebral palsy from assisted conception: a population-based cohort study.

BACKGROUND: This paper assesses the risk of cerebral palsy (CP) in children born after assisted conception compared with children born after natural conception (NC). METHODS: This population based follow-up study included all 588,967 children born in Denmark from 1995 to 2003. Assisted conception was defined as IVF, with or without ICSI, and ovulation induction (OI), with or without subsequent insemination. RESULTS: There were 33 139 (5.6%) children born in Denmark from 1995 to 2003 as a result of assisted conception and through to June 2009, 1146 (0.19%) children received a CP diagnosis. Children born after assisted conception had an increased risk of a CP diagnosis, crude hazard rate ratio (HRR) 1.90 (95% CI: 1.57-2.31) compared with NC children. Divided into IVF and OI children compared with NC children, the risk was HRR 2.34 (95% CI: 1.81-3.01) and HRR 1.55 (95% CI: 1.17-2.06), respectively. When we included the intermediate factors multiplicity and gestational age in multivariate models, the risk of CP in assisted conception disappeared. In general, children with CP born after assisted conception had similar CP subtypes and co-morbidities as children with CP born after NC. CONCLUSION: The risk of CP is increased after both IVF and OI. The increased risk of CP in children born after assisted conception, and in particular IVF, is strongly associated with the high proportion of multiplicity and preterm delivery in these pregnancies. A more widespread use of single embryo transfer warrants consideration to enhance the long-term health of children born after IVF.

Validation of self-reported data on assisted conception in The Danish National Birth Cohort.

BACKGROUND: 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. METHODS: 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. RESULTS: 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). CONCLUSIONS: 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.

Assisted reproductive technology and major structural birth defects in the United States.

BACKGROUND: With >1% of US births occurring following use of assisted reproductive technology (ART), it is critical to examine whether ART is associated with birth defects. METHODS: We analyzed data from the National Birth Defects Prevention Study, a population-based, multicenter, case-control study of birth defects. We included mothers of fetuses or live-born infants with a major birth defect (case infants) and mothers who had live-born infants who did not have a major birth defect (control infants), delivered during the period October 1997-December 2003. We compared mothers who reported ART use (IVF or ICSI) with those who had unassisted conceptions. Multiple logistic regression was used to adjust for the following confounders: maternal race/ethnicity, maternal age, smoking and parity; we stratified by plurality. RESULTS: ART was reported by 1.1% of all control mothers, and by 4.5% of control mothers 35 years or older. Among singleton births, ART was associated with septal heart defects (adjusted odds ratio [aOR] = 2.1, 95% confidence intervals [CI] 1.1-4.0), cleft lip with or without cleft palate (aOR = 2.4, 95% CI 1.2-5.1), esophageal atresia (aOR = 4.5, 95% CI 1.9-10.5) and anorectal atresia (aOR = 3.7, 95% CI 1.5-9.1). Among multiple births, ART was not significantly associated with any of the birth defects studied. CONCLUSIONS: These findings suggest that some birth defects occur more often among infants conceived with ART. Although the mechanism is not clear, couples considering ART should be informed of all potential risks and benefits.

Trends in embryo transfer practices and multiple gestation for IVF procedures in the USA, 1996-2002.

BACKGROUND: Increasing use of IVF in the USA has been a major contributor to the rising national multiple birth rate. Many have advocated that reducing the number of embryos transferred is essential for addressing the IVF-associated multiple birth problem. METHODS: A population-based sample of 506 072 IVF transfers performed in the USA in 1996-2002 was used to investigate trends in embryo transfer practices and to determine whether any changes in practice patterns have impacted the multiple gestation risk associated with IVF. RESULTS: The proportion of procedures in which >or=3 embryos were transferred declined significantly for most patient groups between 1996 and 2002. However, declines for some groups were not sizeable (from 79 to 73% and from 76 to 71% for fresh, non-donor procedures among women aged 38-40 and 41-42 years respectively) and transferring >or=3 embryos remained the norm for all groups. As of 2002, single embryo transfer had not increased for most groups and remained uncommon. Some declines in overall multiple gestation rates were observed, although multiple gestation risk associated with 2 embryos transferred increased significantly for all groups. CONCLUSIONS: Despite changes in embryo transfer practices, multiple gestation risk remains high, in part due to increased multiple gestation rates associated with the transfer of two embryos.

Multiple-birth risk associated with IVF and extended embryo culture: USA, 2001.

BACKGROUND: Multiple births are associated with serious adverse infant and maternal outcomes. The objective of this study was to assess the multiple-birth risk (MBR) associated with IVF and determine whether the risk is impacted by stage of embryo development at transfer. METHODS: A population-based sample of 50 819 IVF transfers utilizing day 3 or day 5 embryos performed in the USA in 2001 on women aged 20-40 years was used to assess MBR and live-birth rate (LBR), stratified by patient age, supernumerary embryo availability, and number of embryos transferred. RESULTS: Although significantly more day 5 than day 3 transfers used < or =2 embryos (69.2 versus 27.7%), the former were not associated with decreased MBR. MBR was high when >1 embryo was transferred, irrespective of embryo development stage. LBR were generally maximized with 2 embryos transferred, and for some (day 5 transfers, patients aged 35-37 years) with one embryo. Electing to transfer a single day 5 embryo appeared efficacious for some patients: women aged 20-37 years with supernumerary embryos cryopreserved had LBR of 31.6-39.5%. CONCLUSIONS: MBR is high when > or =2 embryos are transferred. Single embryo transfer is the only way to prevent many multiple births and associated adverse health outcomes.

Research hurdles complicating the analysis of infertility treatment and child health.

Research aimed at the empirical evaluation of infertility treatment including assisted reproductive technologies (ART) on child health and development is hampered by investigators' inability to methodologically separate possible treatment effects from underlying fecundity impairments. While the literature continues to identify ART as a risk factor for many child health outcomes, less attention has been paid to the methodologic rigor needed to answer this question. We identify aspects of fecundity and the nuances of medical practice that need to be considered and captured when designing epidemiologic investigations aimed at assessing ART and child health. These include: (i) the use of prospective study designs in which the unit of analysis (cycle versus individual versus couple) is defined; (ii) data collection on relevant time-varying covariates at, before and during treatment; and (iii) the use of statistical techniques appropriate for hierarchical data and correlated exposures. While none of these issues in and by itself is unique to ART research, attention to these issues has been lacking in much of the published research limiting our ability to evaluate health consequences for children. Longitudinal studies of children conceived with ART will benefit from attention to these issues and, hopefully, produce answers to lingering questions about safety.

Risk of multiple birth associated with in vitro fertilization using donor eggs.

Multiple birth, which is associated with adverse fetal, infant, and maternal outcomes, is increasingly related to the use of in vitro fertilization (IVF). Among women undergoing IVF who use their own eggs, greater maternal age is associated with decreased risk of multiple birth; using donor eggs from younger women may negate this age effect. Data from 6,936 IVF procedures performed in the United States in 1996-1997 on women aged 35-54 years who used donor eggs were analyzed to assess the effect of maternal age, number of embryos transferred, and cryopreservation of extra, nontransferred embryos (an indicator of higher embryo quality) on risk of multiple birth. Greater maternal age did not decrease multiple-birth risk. Rates of multiple birth were related to number of embryos transferred and whether extra embryos had been cryopreserved, and they were high compared with those of IVF patients the same age who had used their own eggs. Among women who had extra embryos cryopreserved, transferring more than two embryos increased multiple-birth risk, with no corresponding increase in the chance for a livebirth. These results highlight the need to consider the age of the donor and embryo quality when making embryo transfer decisions involving use of donor eggs.

Obesity in women of childbearing age: risks, prevention, and treatment.

This article reviews the health burden of obesity, its treatment and prevention, and potential barriers to care with special emphasis on adult women of childbearing age. From 1988 to 1994, 22% of nonpregnant women 18-49 years old in the United States were overweight (body mass index [BMI] >/= 25-29.9), and 22% were obese (BMI >/= 30). Both conditions increase the risk of chronic disease and mortality, and among women of childbearing age, overweight and obesity also increase the risk of infertility and adverse pregnancy outcomes.The three main strategies for preventing obesity are weight maintenance, weight loss for overweight and obese persons, and physical activity for all. More than 44% of nonpregnant women of childbearing age are trying to lose weight, and more than 33% are trying to maintain weight, but less than 21% of women of childbearing age use the recommended combination of physical activity and caloric restriction to try to lose or maintain weight. Pregnant women should try to gain no more than the recommended weight gain range for their prepregnancy BMI, yet about one third gain more weight.Although research has shown that advice from physicians can have an impact on their patients' eating habits and physical activity, many health professionals either provide no such advice or give inappropriate advice to women of childbearing age. Barriers may include inadequate reimbursement, time constraints, and lack of professional training. Frequent contact with women of childbearing age provides obstetricians and gynecologists and nurse specialists an opportunity to prevent and treat obesity successfully.

High and low hemoglobin levels during pregnancy: differential risks for preterm birth and small for gestational age.

OBJECTIVE: To examine the association of maternal hemoglobin during pregnancy with preterm birth and small for gestational age (SGA). METHODS: We performed a retrospective cohort analysis of hemoglobin and birth outcome among 173,031 pregnant women who attended publicly funded health programs in ten states and delivered a liveborn infant at 26-42 weeks' gestation. We defined preterm as less than 37 weeks' gestation and SGA as less than the tenth percentile of a US fetal growth reference. RESULTS: Risk of preterm birth was increased in women with low hemoglobin level in the first and second trimester. The odds ratio (OR) for preterm birth with moderate-to-severe anemia during the first trimester (more than three standard deviations [SD] below reference median hemoglobin, equivalent to less than 95 g/L at 12 weeks' gestation) was 1.68 (95% confidence interval [CI] 1.29, 2. 21). Anemia was not associated with SGA. High hemoglobin level during the first and second trimester was associated with SGA but not preterm birth. The ORs for SGA in women with very high hemoglobin level during the first and second trimester (more than three SDs above reference median hemoglobin, equivalent to greater than 149 g/L at 12 weeks' gestation and greater than 144 g/L at 18 weeks') were 1.27 (95% CI 1.02, 1.58) and 1.79 (95% CI 1.49, 2.15), respectively. CONCLUSION: These data highlight the importance of considering anemia and high hemoglobin level as indicators for adverse pregnancy outcome. An elevated hemoglobin level (greater than 144 g/L) is an indicator for possible pregnancy complications associated with poor plasma volume expansion, and should not be mistaken for good iron status.

Does assisted hatching pose a risk for monozygotic twinning in pregnancies conceived through in vitro fertilization?

OBJECTIVE: To examine the association between assisted hatching and monozygotic (MZ) twinning. DESIGN: Case-control. SETTING: Population-based sample of IVF-ET cycles initiated in U.S. clinics, 1996. PATIENT(S): The IVF-ET (n = 35,503) cycles and 11,247 resultant pregnancies. INTERVENTION(S): Use of an assisted hatching procedure on embryos transferred. MAIN OUTCOME MEASURE(S): Cases were pregnancies for which number of fetal hearts observed on ultrasound exceeded number of embryos transferred. These pregnancies were considered to contain at least one MZ set of twins. Cases were compared with two control groups: other multiple-gestation pregnancies (>/=2 fetal hearts but number of fetal hearts

Prepregnancy body mass index and pregnancy weight gain: associations with preterm delivery. The NMIHS Collaborative Study Group.

OBJECTIVE: To examine associations between rate of pregnancy weight gain and preterm delivery among women of varying prepregnancy body mass indices (BMI). METHODS: Subjects were 3511 mother-infant pairs from the 1988 National Maternal and Infant Health Survey. Prenatal weight measured between 14 and 28 weeks' gestation was used to calculate rate of pregnancy weight gain for each woman. Weight gain (lb/week) was categorized as low (under 0.5), average (0.5-1.5), or high (above 1.5). Prepregnancy BMI was calculated as weight divided by height in (kg/m(2)) and categorized as low (under 19.8), average (19.8-26.0), and high (above 26). Delivery before 37 weeks' gestation was considered preterm. Associations between BMI, weight gain, and preterm delivery were examined before and after exclusion of medically indicated preterm deliveries and pregnancies complicated by maternal medical conditions potentially related to weight gain or fetal growth restriction. Associations were expressed as odds ratios (OR) adjusted for several potential confounding factors. RESULTS: Women with low pregnancy weight gain were at increased risk of preterm delivery. The magnitude of risk varied according to a woman's prepregnancy BMI. After all exclusions and adjustments for confounders, ORs, and 95% confidence intervals (CI) for low pregnancy weight gain were 6.7 (1.1, 40.6) for underweight women, 3.6 (1.6, 8.0) for average-weight women, and 1.6 (0.7, 3.5) for overweight women compared with average-weight women with average pregnancy weight gain. CONCLUSIONS: Low weight gain in pregnancy was associated with increased risk of preterm delivery, particularly if women were underweight or of average weight before pregnancy.

Validity of self-reported pregnancy delivery weight: an analysis of the 1988 National Maternal and Infant Health Survey. NMIHS Collaborative Working Group.

This study examined the validity of self-reported delivery weight among 3,518 respondents to the 1988 National Maternal and Infant Health Survey. Self-reported delivery weight was ascertained from a mail survey administered during the postpartum period. Measured delivery weight was obtained by abstraction of medical records from the hospital of delivery. On average, a woman's reported delivery weight was 2.82 pounds (1 pound = 0.45 kg) less than her measured delivery weight (p < 0.001). The level of underreporting increased significantly with increases in prepregnancy body mass index, current body mass index, pregnancy weight gain, and weight change from delivery to recall. Reporting error also increased among women who were non-White, less educated, and unmarried; whose pregnancy was unintended; and who initiated prenatal care late, responded late to the survey questionnaire, became pregnant again before responding, and reported a delivery weight ending in zero. When reported delivery weight was used to calculate weight gain and was categorized into typical weight gain categories, 30-40% of women were classified incorrectly. An empirical evaluation of how this misclassification might impact epidemiologic analyses indicated that associations between weight gain and birth weight were attenuated when weight gain was based on reported delivery weight rather than on measured delivery weight.

Live-birth rates and multiple-birth risk using in vitro fertilization.

CONTEXT: To maximize birth rates, physicians who perform in vitro fertilization (IVF) often transfer multiple embryos, but this increases the multiple-birth risk. Live-birth and multiple-birth rates may vary by patient age and embryo quality. One marker for embryo quality is cryopreservation of extra embryos (if embryos are set aside for cryopreservation, higher quality embryos may have been available for transfer). OBJECTIVE: To examine associations between the number of embryos transferred during IVF and live-birth and multiple-birth rates stratified by maternal age and whether extra embryos were available (ie, extra embryos cryopreserved). DESIGN AND SETTING: Retrospective cohort of 300 US clinics reporting IVF transfer procedures to the Centers for Disease Control and Prevention in 1996. SUBJECTS: A total of 35554 IVF transfer procedures. MAIN OUTCOME MEASURES: Live-birth and multiple-birth rates (percentage of live births that were multiple). RESULTS: A total number of 9873 live births were reported (multiple births from 1 pregnancy were counted as 1 live birth). The number of embryos needed to achieve maximum live- birth rates varied by age and whether extra embryos were cryopreserved. Among women 20 to 29 years and 30 to 34 years of age, maximum live-birth rates (43 % and 36%, respectively) were achieved when 2 embryos were transferred and extra embryos were cryopreserved. Among women 35 years of age and older, live-birth rates were lower overall and regardless of whether embryos were cryopreserved, live-birth rates increased if more than 2 embryos were transferred. Multiple-birth rates varied by age and the number of embryos transferred, but not by whether embryos were cryopreserved. With 2 embryos transferred, multiple-birth rates were 22.7%, 19.7%, 11.6%, and 10.8% for women aged 20 to 29, 30 to 34, 35 to 39, and 40 to 44 years, respectively. Multiple-birth rates increased as high as 45.7% for women aged 20 to 29 years and 39.8% for women aged 30 to 34 years if 3 embryos were transferred. Among women aged 35 to 39 years, the multiple-birth rate was 29.4% if 3 embryos were transferred. Among women 40 to 44 years of age, the multiple-birth rate was less than 25% even if 5 embryos were transferred. CONCLUSIONS: Based on these data, the risk of multiple births from IVF varies by maternal age and number of embryos transferred. Embryo quality was not related to multiple birth risk but was associated with increased live-birth rates when fewer embryos were transferred.

Medically advised, mother's personal target, and actual weight gain during pregnancy.

OBJECTIVE: To evaluate whether advice on pregnancy weight gain from health care professionals, women's target weight gain (how much weight women thought they should gain), and actual weight gain corresponded with the 1990 Institute of Medicine recommendations. METHODS: Predominantly white, middle-class women participating in a mail panel reported their prepregnancy weights, heights, and advised and target weight gains on a prenatal questionnaire (n = 2237), and their actual weight gains on a neonatal questionnaire (n = 1661). Recommended weight gains were categorized for women with low body mass index (BMI) (less than 19.8 kg/m2) as 25-39 lb; for women with average BMI (19.8-26.0 kg/m2) as 25-34 lb; and for women with high BMI (more than 26.0-29.0 kg/m2) and very high BMI (more than 29.0 kg/m2) as 15-24 lb. RESULTS: Twenty-seven percent of the women reported that they had received no medical advice about pregnancy weight gain. Among those who received advice, 14% (95% confidence interval [CI] 12%, 16%) had been advised to gain less than the recommended range and 22% (95% CI 20%, 24%) had been advised to gain more than recommended. The odds of being advised to gain more than recommended were higher among women with high BMIs and with very high BMIs compared with women with average BMIs. Black women were more likely than white women to report advice to gain less than recommended. Advised and target weight gains were associated strongly with actual weight gain. Receiving no advice was associated with weight gain outside the recommendations. CONCLUSION: Greater efforts are required to improve medical advice about weight gain during pregnancy.