Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Birth Rate”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 109 records · Page 6Linked to original sources
PubMed2005

Elective transfer of single fresh blastocysts and later transfer of cryostored blastocysts reduces the twin pregnancy rate and can improve the in vitro fertilization live birth rate in younger women.

OBJECTIVE: To determine the extent to which embryo selection by blastulation and elective single blastocyst transfer, supported by efficient cryostorage of spare embryos, can reduce multiple pregnancies and maintain or improve on the live birth rate from IVF. DESIGN: Prospective, nonrandomized cohort study. SETTING: Sydney IVF, a private clinic in Australia. PATIENT(S): In vitro fertilization patients aged <38 years with three or more usable blastocyst, recruited from April 2000 through December 2001, with pregnancies followed up until August 2004. INTERVENTION(S): Blastocysts were cultured and cryostored with stage-specific culture medium and low oxygen conditions. MAIN OUTCOME MEASURE(S): Fetal heart-positive twin pregnancy rate and accumulating "take-home baby" rate per retrieval leading to blastocyst transfer. RESULT(S): Among 121 women who elected single fresh blastocyst transfer (but who could elect to have two frozen blastocysts transferred at once), 79 (65.3%) took home a baby, with a twin pregnancy rate of 7%. Among 285 women who chose two blastocysts for fresh transfer, 184 (64.2%) took home at least one baby, with a twin pregnancy rate of 34% and five perinatal deaths. CONCLUSION(S): With technically appropriate blastocyst culture and freezing, and elective single blastocyst transfer in the fresh cycle, the overall multiple pregnancy rate can be reduced by >75%, permitting in this series a slight increase in the chance of taking home a baby.

Adult↗
PubMed1987

Seasonality in twin birth rates, Denmark, 1936-84.

A study was made of seasonality in twin birth rate in Denmark between 1977 and 1984. We studied all twin births (N = 45,550) in all deliveries (N = 3,679,932) during that period. Statistical analysis using a simple harmonic sinusoidal model provided no evidence for seasonality. However, sequential polynomial analysis disclosed a significant fit to a fifth order polynomial curve with peaks in twin birth rates in May-June and December, along with troughs in February and September. A falling trend in twinning rate broke off in Denmark around 1970, and from 1970 to 1984 an increasing trend was found. The results are discussed in terms of possible environmental influences on twinning.

Birth Rate↗
PubMed1991

Relationship of follicle number, serum estradiol, and other factors to birth rate and multiparity in human menopausal gonadotropin-induced intrauterine insemination cycles.

OBJECTIVE: To determine the characteristics associated with pregnancy and multiple gestation after human menopausal gonadotropin intrauterine insemination (hMG-IUI). DESIGN: Prospective study of all patients undergoing hMG-IUI between January 1, 1984 and December 31, 1989. SETTING: University affiliated private clinic. PATIENTS: Four hundred twenty-four infertility patients undergoing 779 cycles of hMG-IUI. MAIN OUTCOME MEASURES: The relationship between estradiol (E2), number and size of follicles, age, and initial semen quality on pregnancy and multiple gestations in hMG-IUI cycles. RESULTS: The number of follicles greater than or equal to 12 mm was correlated with births and predicted all multiple births (r = 0.140, P less than 0.001). The corrected birth rate was 25.8% for age less than 35 and 14.0% for age greater than or equal to 35 when four or more follicles were greater than or equal to 12 mm. The uncorrected clinical pregnancy rate (PR) and birth rate were 12.8% and 10.5%, respectively. Decreased births were associated with tubal adhesions alone (P less than 0.03) or with endometriosis (P less than 0.002), more than four cycles of treatment (P = 0.01), initial sperm count less than 5 x 10(6) per mL (P less than 0.01), initial sperm motility less than 30% (P less than 0.002), and age greater than or equal to 35 (P less than 0.01). Estradiol was correlated with birth rate (r = 0.160, P less than 0.001), which increased from 3.6% when E2 was less than 500 pg/mL to 19.6% when E2 was greater than or equal to 2,500 pg/mL. CONCLUSIONS: The outcome of hMG-IUI is related to the number of follicles greater than or equal to 12 mm, to E2, and to age. Optimal PRs from hMG-IUI require mild ovarian hyperstimulation.

Adult↗
PubMed2002

Hereditary thrombophilias are not associated with a decreased live birth rate in women with recurrent miscarriage.

OBJECTIVE: To assesses the live birth rate without treatment in women with hereditary thrombophilia who have recurrent miscarriage and women without thrombophilia who have recurrent miscarriage. DESIGN: Prospective observational study. SETTING: Tertiary referral unit in university hospital. PATIENT(S): One hundred twenty women with thrombophilia and 65 women without thrombophilia. MAIN OUTCOME MEASURE(S): Number of live births or repeated miscarriages. RESULTS: Of the 185 patients, 44 with thrombophilia and 26 without thrombophilia have conceived. Nineteen of the 44 pregnancies (43.2%) in thrombophilia patients have terminated in live births, compared with 8 of 26 pregnancies (30.8%) in patients without thrombophilia. This difference is not statistically significant. CONCLUSIONS: Hereditary thrombophilia did not seem to affect the live birth rate in women with recurrent miscarriage.

Abortion, Habitual↗
PubMed2006

Fertility rates and future population trends: will Europe's birth rate recover or continue to decline?

Europe has long completed its demographic transition from high birth and death rates to low birth and death rates. But the demographic transition paradigm that has been very useful for explaining global demographic trends during the 20th century and that still has strong predictive power when it comes to projecting future trends in countries that still have high fertility, has nothing to say about the future of fertility in Europe. The currently popular notion of a 'second demographic transition' is a useful way to describe a bundle of behavioural and normative changes that recently happened in Europe, but it has no predictive power. The social sciences have not yet come up with a useful theory to predict the future fertility level of post-demographic transition societies. We even do not know whether the trend will be up or down. Given the lack of a predictive theory, this paper will try to do two things: (i) Summarize different substantive arguments that would either suggest the assumption of a recovery of fertility rates in Europe or alternatively, imply further declines. (ii) Convert this discussion of the uncertainty of future fertility trends into probabilistic population projections for Europe, thus highlighting the implications of alternative fertility levels over the coming years. We will also discuss trade-offs between fertility and immigration, and the phenomenon that Europe now has entered a period of negative momentum of population growth.

Birth Rate↗
PubMed1994

Cumulative conception and live-birth rates after in vitro fertilization with and without the use of long, short, and ultrashort regimens of the gonadotropin-releasing hormone agonist buserelin.

OBJECTIVE: Our purpose was to compare cumulative conception and live-birth rates after in vitro fertilization with and without the use of the long, short, and ultrashort regimens of the gonadotropin-releasing hormone agonist buserelin. STUDY DESIGN: Life-table analysis of conception and live-birth rates in relation to ovarian stimulation regimen used in 2893 women who had one of five stimulation regimens exclusively throughout all treatment cycles, namely, human menopausal gonadotropin with or without clomiphene citrate; follicle-stimulating hormone with or without clomiphene citrate; and long, short, and ultrashort protocols of buserelin, plus follicle-stimulating hormone or human menopausal gonadotropin; and in an additional 347 women who had been administered both human menopausal gonadotropin and follicle-stimulating hormone with or without clomiphene citrate. RESULTS: The cumulative conception rate and cumulative live-birth rate were significantly higher in those women treated exclusively with the long buserelin regimen (59% and 55%, respectively, after three cycles) compared with those who only had human menopausal gonadotropin or follicle-stimulating hormone with or without clomiphene citrate (39% and 29%, respectively, after three cycles) (p = 0.001 and p = 0.0001) or compared with those who had only short or ultrashort buserelin regimens (22% and 17% after two cycles) (p = 0.0001 and p = 0.005). The pregnancy failure rate in patients on the long buserelin regimen was 22.4% (95% confidence interval 14.8% to 30.0%) compared with 33.3% (95% confidence interval 29.6% to 37.0%) in those who had human menopausal gonadotropin or follicle-stimulating hormone with or without clomiphene citrate (p = 0.03). When the probabilities of first conception and first live birth were examined by treatment regimen, after we allowed for the effects of age, cause of infertility, calendar year of treatment, and treatment cycle number (with a multiple logistic regression model), it was found that, relative to human menopausal gonadotropin or follicle-stimulating hormone with or without clomiphene citrate, the odds of conceiving with the long buserelin regimen was 1.63 (95% confidence interval 1.31 to 2.03) (p < 0.001) and the odds of a live birth was 1.97 (95% confidence interval 1.53 to 2.54) (p < 0.001). Similarly, relative to short or ultrashort buserelin the odds of conceiving with long bureselin was 1.88 (95% confidence interval 1.39 to 2.55) (p < 0.001) and the odds of a live birth was 1.79 (95% confidence interval 1.25 to 2.56) (p = 0.001). CONCLUSION: Pituitary desensitization with the long protocol of buserelin significantly increases the probabilities of conception and live birth after in vitro fertilization.

Adult↗
PubMed2004

Birth rate among patients with epilepsy: a nationwide population-based cohort study in Finland.

Few reports on population-based studies of birth rate among epilepsy patients have been published. In most previous studies, fertility has been lower among epilepsy patients than in the rest of the population. However, conflicting results have also been reported. Because of small samples and selective material, the generalizability of these results is also limited. The authors conducted a population-based cohort study of birth rate (1985-2001) in a nationwide Finnish cohort of patients with newly diagnosed epilepsy and a population-based reference cohort. All patients (n = 14,077) approved as eligible for reimbursement for antiepileptic medication from the Social Insurance Institution of Finland (KELA) for the first time between 1985 and 1994 were identified from the KELA database. A reference cohort (n = 29,828) was identified from the Finnish Population Register Center, with frequency-matching on age. Information on follow-up status and livebirths were also obtained from the Finnish Population Register Center. The birth rate was lower in patients with epilepsy than in the reference cohort among both men (hazard ratio = 0.58, 95% confidence interval: 0.54, 0.62) and women (hazard ratio = 0.88, 95% confidence interval: 0.83, 0.93). There were a clear decreasing trend by age at observation in men with epilepsy and a moderate decreasing trend by age at start of follow-up in women with epilepsy.

Adolescent↗
PubMed2003

Thromboprophylaxis improves the live birth rate in women with consecutive recurrent miscarriages and hereditary thrombophilia.

The effect of thromboprophylaxis with low molecular weight heparin (LMWH), on the subsequent live birth rate, in thrombophilic women with recurrent miscarriage has not been sufficiently assessed. The present study is a cohort study undertaken to assess the effect of enoxaparin on the subsequent live birth rate in women with hereditary thrombophila. Eighty-five patients with three or more consecutive pregnancy losses and a hereditary thrombophilia subsequently conceived. Thirty-seven were treated with daily subcutaneous injections of enoxaparin 40 mg and 48 were not treated. The outcome of the subsequent pregnancy was assessed in both groups of patients in terms of live births or repeat miscarriage. Forty-seven of the 85 patients were subsequently delivered, 38 have miscarried. Twenty-six of the 37 pregnancies in treated patients (70.2%) resulted in live births, compared with 21 of 48 (43.8%) in untreated patients (P < 0.02, OR 3.03, 95% CI 1.12-8.36). The beneficial effect was seen mainly in primary aborters, i.e. women with no previous live births (P < 0.008, OR 9.75, 95% CI 1.59-52.48). This benefit was also found in patients with a poor prognosis for a live birth (five or more miscarriages), where the live birth rate was increased from 18.2% to 61.6%. However, the benefit was not statistically significant, probably due to the small number of patients. If the beneficial effects of enoxaparin are confirmed by additional studies, thromboprophylaxis can be recommended for patients with hereditary thrombophilia and recurrent pregnancy loss.

Abortion, Habitual↗
PubMed2006

A relative reduction in mid-follicular LH concentrations during GnRH agonist IVF/ICSI cycles leads to lower live birth rates.

BACKGROUND: The effect of early- and mid-follicular LH concentrations on the ovarian response and pregnancy outcomes was evaluated in women receiving pituitary down-regulation with a GnRH agonist and ovarian stimulation with recombinant FSH (rFSH) during IVF/ICSI treatment. METHODS: Blood samples were collected prospectively from 701 cycles (560 patients) of assisted reproduction and analysed retrospectively. On the basis of LH concentrations on stimulation day 7/8, the patients were divided into two groups: LH<1.2 IU/l (n=179) and LH>or=1.2 IU/l (n=522). Cycle outcomes were also compared on the basis of a ratio of mid- to early-follicular LH concentrations ( 0.5, n=491). RESULTS: Patients with low LH concentrations were found to have a significant reduction in the late-follicular estradiol concentrations (P<0.001), the number of oocytes retrieved (P<0.01) and the number of usable embryos (P<0.01), and they required significantly more rFSH (430 IU difference, P<0.01). These differences did not translate into a significant change in live birth rates. Conversely, a ratio of or=50%) was associated with a significant reduction in live birth rates per embryo transfer and per cycle started (27.3 versus 19.0%, P<0.05 and 22.2 versus 15.8%, P<0.05, respectively). CONCLUSIONS: Low mid-follicular levels of LH have a significant impact on ovarian response but not on live birth rates. A fall in LH level of >or=50% from the early- to mid-follicular phase resulted in a lower live birth rate.

Adult↗
PubMed1998

Cummulative pregnancy and live birth rates after assisted conception.

Within the last 15 years in vitro fertilization (IVF) has become an established treatment modality. Its results compare favorably with that of spontaneous conception in the natural menstrual cycle in fertile women. The possibility of a success for any couple undergoing treatment will, however, depend on their characteristics. Over the past several years, the importance of these individual factors has been subjected to an extensive research. Our group has performed a number of studies that relate the cumulative conception rate (CCR) and cumulative live birth rate (CLR) with the age of the patient, the cause of infertility, and the type of ovarian stimulation used. We have also analyzed the effect of previously successful in vitro fertilization treatment upon the results of a subsequent treatment course, and the obstetric outcome of in vitro fertilization pregnancies when compared to those that are naturally conceived. In this review article, the importance of the above mentioned factors will be discussed in view of our research results and other recently available evidence.

Birth Rate↗
PubMed2006

An energy-saving development initiative increases birth rate and childhood malnutrition in rural Ethiopia.

BACKGROUND: Evolutionary life history theory predicts that, in the absence of contraception, any enhancement of maternal condition can increase human fertility. Energetic trade-offs are likely to be resolved in favour of maximizing reproductive success rather than health or longevity. Here we find support for the hypothesis that development initiatives designed to improve maternal and child welfare may also incur costs associated with increased family sizes if they do not include a family planning component. METHODS AND FINDINGS: Demographic and anthropometric data were collected in a rural Ethiopian community benefiting from a recent labour-saving development technology that reduces women's energetic expenditure (n = 1,976 households). Using logistic hazards models and general linear modelling techniques, we found that whilst infant mortality has declined, the birth rate has increased, causing greater scarcity of resources within households. CONCLUSIONS: This study is, to our knowledge, the first to demonstrate a link between a technological development intervention and an increase in both birth rate and childhood malnutrition. Women's nutritional status was not improved by the energy-saving technology, because energy was diverted into higher birth rates. We argue that the contribution of biological processes to increased birth rates in areas of the developing world without access to modern contraception has been overlooked. This highlights the continued need for development programmes to be multisectoral, including access to and promotion of contraception.

Adolescent↗
PubMed2005

The age pattern of first-birth rates among U.S. women: the bimodal 1990s.

Between 1990 and 2002, the age pattern of Type I first-birth rates (i.e., the hazard of a first birth) among U.S. women was bimodal. This pattern, driven by changing differential fertility patterns among racial and ethnic groups, reached its apex at the mid-1990s and had almost vanished by the decade's end. Research on first-birth timing has tended to focus on Type II first-birth rates and therefore has failed to identify this larger, bimodal pattern. This article presents the benefits of using Type I rates, documents the emergence of the bimodal pattern via two new measures of bimodality, and uses a decomposition analysis to discuss the pattern's causes.

Adolescent↗
PubMed2004

The effect of seasonal host birth rates on population dynamics: the importance of resonance.

Many of the simple mathematical models currently in use often fail to capture important biological factors. Here we extend current models of insect-pathogen interactions to include seasonality in the birth rate. In particular, we consider the SIR model with self-regulation when applied to specific cases--rabbit haemorrhagic disease and fox rabies. In this paper, we briefly summarize the results of the model with a constant time-independent birth rate, a, which we then replace with the time dependent birth rate a(t), to investigate how this effects the dynamics of the host population. We can split parameter space into an area in which the model without seasonality has no oscillations, in which case a simple averaging rule predicts the behaviour. Alternatively, in the area where oscillations to the equilibrium do occur in the non-seasonal model, disease persistence is more complicated and we get more complex dynamical behaviour in this case. We apply resonance techniques to discover the structure of the subharmonic modes of the SIR model with self-regulation. We then look at whether many biological systems are likely to display these "resonant" dynamics and find that we would expect them to be widespread.

Animals↗
PubMed2001

Trends in birth rates: New York City 1970-1995.

Traditional means of assessing the problem of teen pregnancy have relied on national or state statistics. By using large geographic areas, usually comprised of a heterogeneous population, it is impossible to tell which subareas have more of a problem than others. This study focused on trends in teen birth rates at the health district level in New York City over a 25-year period to illustrate variations among ethnic groups. Teen birth rates were calculated based on vital statistics published by the New York City Department of Health. They were calculated as the number of births per 1,000 females in each of three age groups: under age 15, 15-17, and 18-19. Rates were calculated for the entire City, for four boroughs, and for selected health center districts. The decline in the birth rate among New York City teens is most significant in health districts populated by blacks. An exception is the noted increases in birth rates in districts populated predominantly by Hispanics. Data show substantial decreases among older teens compared to younger teens. Birth trends in small areas of New York City mirror trends seen nationwide. As migration changes the ethnic composition of small areas, it is important to monitor trends so that policies and programs can be targeted to those in need.

Adolescent↗