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PubMed1996

Fertility patterns according to occupational grouping in Norway, 1989.

In the early 1990s, most pregnant women in Norway were in gainful employment. This led to increased interest in the possible consequences for reproductive health, and a growing concern for the need to accommodate the pregnancy. We have therefore investigated how accurately general fertility rates predict the number of pregnancies in the workforce. Fertility rates (FR) among employed women and standardized fertility ratios (SFR) in occupational groups were estimated on the basis of information from the Labour Market Statistics and the national survey "Pregnancy and Work", Norway, 1989. The fertility rate among employed women was 17% higher than the general fertility rate. Two occupational groups had significantly different SFRs: technical/professional workers (SFR 118) and transport/communication workers (SFR 82). In addition, differences were found for parity-specific SFRs in administrative/executive work (SFR nullipara 80, SFR para 125) and service work (SFR nullipara 114, SFR para 80). We suggest that work status and occupation should be included among the variables registered in the Medical Birth Registry of Norway, in order to facilitate routine presentations of fertility rates and pregnancy outcomes for women in paid work. The results further indicate that work-specific conditions influence first-birth fertility. This should be explored in demographic studies of the relation between women's fertility and participation in paid work.

Adolescent↗

PubMed2006

Sibling oocyte submission to IVF and ICSI in unexplained infertility patients: a potential assay for gamete quality.

In order to reduce total fertilization failure in unexplained infertility, sibling oocytes were submitted to both conventional IVF and intracytoplasmic sperm injection (ICSI). Two groups of ICSI embryos were compared in unexplained infertility patients: those derived from ICSI when IVF had failed to fertilize, and those derived from ICSI while their sibling oocytes were fertilized by IVF. The outcome of oocytes fertilized exclusively by ICSI (essential ICSI, n = 749) was compared with those fertilized both by IVF and ICSI (non-essential ICSI, n = 957) in all IVF patients treated for unexplained infertility at the Hadassah Hospital (1999-2002). The latter group was further subdivided into ICSI and IVF embryos. Total fertilization rate was 54%. Fertilization rates by ICSI were lower in the essential ICSI compared with the non-essential ICSI group, at 65 and 73% (P < 0.025). Pregnancy rates per embryo transfer in the essential ICSI group (49%), ICSI derived embryos group (55%) and IVF derived embryos (44%) from the non-essential ICSI group, were similar. Implantation rates were lower in the essential ICSI group as compared with the non-essential ICSI group (21 versus 32% respectively; P < 0.05) and 26% for IVF embryos. In conclusion, essential ICSI was associated with lower fertilization and implantation rates.

Adult↗

PubMed2006

Association between sperm autoantibodies and enhanced embryo implantation rates during in vitro fertilization.

Previous investigations have demonstrated the propensity of strong IgA-class sperm autoantibodies to impede fertilization. However, because there has not been a general consensus on this issue, the aim of this retrospective analysis was to focus on the effects of different levels of IgA-class antibodies on each stage of the IVF procedure. This study has confirmed that high level IgA class antibodies significantly reduce fertilization rates but, unexpectedly, also has shown a very significant improvement in embryo implantation rates in patients with weak to moderate antibody levels. Interlaboratory prospective collaborative studies are being planned to test this preliminary observation more stringently.

Australia↗

PubMed2005

[Intracytoplasmic sperm injection can improve the fertilization limitation following in vitro fertilization during previous cycles].

OBJECTIVE: To evaluate whether or not intracytoplasmic sperm injection (ICSI) can improve previous fertilization limitation on conventional in vitro fertilization (IVF). METHODS: One hundred and thirty-six completed cycles in 113 patients with ICSI treatment were grouped. Group 1 was 106 cycles perform ICSI because of male factor, and group 2 was other 30 cycles with the history of fertilization failure and fertilization rate < 20% on conventional IVF, also assembling the cycles in group 2 according to the fertilization rate. RESULTS: There was no significant difference between two groups in the rates of normal fertilization(70.49% vs 72.02%), good quality embryos (38.28% vs 38.81%), and clinical pregnancy (40.57% vs 40.00%) (P > 0.05). The fertilization rate of a majority of cycles (70.00%, 21/30) in group 2 was higher than 50%, and the mean of fertilization rates was 79.79%. CONCLUSION: ICSI can improve the fertilization limitation following IVF during previous cycles, and the fertilization rates was similar to those treated ICSI because of male factor.

Female↗

PubMed2003

Disordered zona pellucida-induced acrosome reaction and failure of in vitro fertilization in patients with unexplained infertility.

OBJECTIVE: To determine the relationship between the zona pellucida (ZP)-induced acrosome reaction (AR) and fertilization rate and pregnancy rate in standard IVF and the frequency of disordered ZP-induced AR (DZPIAR) in patients with unexplained infertility. DESIGN: Prospective study. SETTING: Academic research and teaching tertiary hospital. PATIENTS: Patients with unexplained infertility with normal semen analysis. INTERVENTION: None. MAIN OUTCOME MEASURE: Semen analysis, the ZP-induced AR, and measurements of fertilization rate and pregnancy rate with in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI). RESULT(S): A statistically significant correlation was found for the ZP-induced AR and fertilization rate with standard IVF (n = 65). Patients with DZPIAR (ZP-induced AR of 16%, who had an average fertilization rate of 61%. The sensitivity and specificity of DZPIAR for prediction of IVF rates <30% and >or=30% were 80% and 86%, respectively. Of 260 patients screened, the frequency of DZPIAR was 29%. Ten patients with DZPIAR had an average fertilization rate of 15% and no pregnancy with initial IVF cycles, and a fertilization rate of 61% (with three live-birth pregnancies) with subsequent ICSI cycles. Another 33 patients with DZPIAR were treated with ICSI alone, with an average fertilization rate of 71% and a live-birth pregnancy rate of 17% per embryo transfer. Sixteen of the patients had live-birth pregnancies (including one set of twins) after undergoing an average of 3.2 embryo transfers. CONCLUSION(S): Patients with DZPIAR have a low or zero fertilization rate with standard IVF but high fertilization and pregnancy rates with ICSI. Up to 29% of patients with unexplained infertility with normal semen analysis may have this condition, which should be diagnosed and treated with ICSI rather then standard IVF.

Acrosome Reaction↗

PubMed1981

FSH or FSH plus LH superovulation in ewes following estrus synchronization with medoxyprogesterone acetate pessaries.

The estrous cycles of 28 ewes 9 to 10 months of age were synchronized with Medoxyprogesterone (MAP) pessaries. Superovulation was attempted by injecting either (follicle stimulating hormone) FSH or FSH plus Luteinizing Hormone (LH). MAP pessaries were in place for 12 days. FSH was administered (IM) to all ewes at 12-hr intervals over a 3-day period, 5 mg injected twice on day 11 after pessary insertion, followed by 4 and 3 mg twice daily on days 12 and 13, respectively. LH (25 mg injected IV) was given to 14 ewes within 8 hr after the onset of behavioral estrus. All ewes were hand mated with several rams at 12-hr intervals from the onset to the end of behavioral estrus. Ovulation, embryo recovery and fertilization rates were recorded for each ewe. Of 14 ewes injected with only FSH, 13 ovulated, with a mean ovulation rate of 8.2 +/- 5.6; embryo recovery rate averaged 62%, and fertilization rate was 97%. All 14 ewes given both FSH + LH ovulated, with an ovulation rate of 8.9 +/- 5.8 per ewe; embryo recovery averaged 70%, and 91% of all embryos recovered were fertilized. No statistical differences in ovulation, embryo recovery or fertilization rates were found between the FSH and FSH + LH superovulation treatment groups. In addition, no difference in the number of ewes showing estrus or duration of behavioral estrus was noted between FSH and FSH + LH treatments.

Animals↗

PubMed1991

Predictive value of classical and automated sperm analysis for in-vitro fertilization.

The fertilization rates observed in 122 attempts at in-vitro fertilization were examined in relation to sperm characteristics assessed by visual and automated screening. Using linear regression analysis, a significant correlation was found between the fertilization rate and (i) evaluations in fresh semen sperm concentration, percentages of sperm motility, vitality and normal morphology and velocity, (ii) measurements in swim-up preparations of percentages of sperm motility, vitality and morphology, velocity and amplitude of lateral head displacement. No significant correlation was found between the fertilization rate and any of the parameters studied in 24-h-old swim-up suspensions. Analysis by multiple variable stepwise linear regression showed an optimal correlation (R6 = 0.62) between the observed fertilization rate and theoretical calculation obtained from the following predictive function: fertilization rate = -0.3 + (0.008 x swim-up motility) + (0.004 x normal sperm morphology in fresh semen). Introduction of kinematic characteristics studied by automated screening improved the multiple correlation between the calculated and observed fertilization rate in cases of normal or mildly defective semen. Because of the limited availability of motile spermatozoa, automated analysis could not supersede classical sperm analysis in cases of more severe sperm defects.

Autoanalysis↗

PubMed1989

Does computerized image analysis of sperm movement enhance the predictive value of semen analysis for in-vitro fertilization results?

The influence of semen quality on fertilization rates in an in-vitro fertilization (IVF) programme was studied by analysing both conventional semen parameters and computerized movement characteristics. The study was based on 407 inseminated oocytes which were obtained from 50 patients in 113 laparoscopies. Sperm concentration did not correlate strongly with the fertilization rate. Sperm motility and morphology were the most meaningful parameters in predicting fertilization success. A drop in fertilization rate was found when sperm motility or normal morphology were below 40%. Sperm velocity measured in semen was the only sperm movement parameter which correlated with the fertilization rate, albeit weakly. The latter was reduced when average sperm velocity in semen was less than 50 microns/sec. Conventional semen parameters seem to be more predictive of the fertilizing potential of an ejaculate than movement characteristics obtained by computerized image analysis.

Fertilization↗

PubMed1994

Use of the acrosome reaction to ionophore challenge test in managing patients in an assisted reproduction program: a prospective, double-blind, randomized controlled study.

OBJECTIVE: To assess the utility of the acrosome reaction (AR) to ionophore challenge test in determining the sperm treatment protocols for patients undergoing assisted reproduction. DESIGN, SETTING, PATIENTS: One hundred twenty-one couples undergoing an IVF-ET or GIFT procedure from January to July 1992 were included in this prospective study. All cases had a preliminary semen analysis within the previous 3 months and an AR to ionophore challenge test was carried out unless an acceptable fertilization rate occurred on previous IVF. For those patients whose AR to ionophore challenge score was below the accepted fertile range of > or = 10%, a second AR to ionophore challenge test was performed after exposure of sperm to the stimulant pentoxifylline. Couples then were managed by assisted reproduction with randomized allocation of oocytes for fertilization with a standard sperm preparation or with added sperm stimulants, either 3.6 mM pentoxifylline alone or combined with 3.0 mM 2-deoxyadenosine. The study was double-blind with neither the patients nor the embryologist knowing the AR to ionophore challenge result at the time of the IVF procedure. MAIN OUTCOME MEASURES: Data from the preliminary semen analyses and AR to ionophore challenge scores were correlated with the fertilization rates achieved using control and treated sperm preparations. The rates of total fertilization failure and the numbers of clinical pregnancies occurring in each subgroup were also recorded. RESULTS: All AR to ionophore challenge groups showed normal sperm counts except the groups with poor AR to ionophore challenge, which demonstrated reduced sperm counts. The group with normal AR to ionophore challenge scores or previous normal fertilization showed satisfactory fertilization rates with either control or treated sperm, although some individual cases showed reduced fertilization with treated sperm. The fertilization rate for the group with low AR to ionophore challenge scores improved significantly with pentoxifylline, and the benefit was greatest when this had been predicted from the AR to ionophore challenge studies. Cases with persisting poor AR to ionophore challenge despite pentoxifylline showed no significant improvement in fertilization rates with sperm exposed to either sperm stimulant regimens. Poor AR to ionophore challenge scores were also predictive of total fertilization failure, but this problem was reduced by sperm stimulation. The AR to ionophore challenge score at 10% cutoff level showed optimal levels of sensitivity (82.1%), highest negative predictive value (82.1%), and lowest false negative rate (17.9%). CONCLUSIONS: The AR to ionophore challenge test is useful in the assessment and management of the male factor in assisted reproduction. It can be used to identify the majority of cases who will benefit from the use of sperm stimulants.

Acrosome↗

PubMed1996

Effects of sperm concentration and egg number on fertilization efficiency with channel catfish (Ictalurus punctatus) eggs and blue catfish (I. furcatus) spermatozoa.

The mean sperm concentration of 10 blue catfish (Ictalurus furcatus ) was 1.03 x 10(10) per gram of testis. Testis weighed 3.9 and 17.2 g, with a mean of 6.6 g per fish. Fertilization rate of channel catfish (Ictalurus punctatus ) eggs fertilized with 5.00 x 10(4) to 1.20 x 10(7) blue catfish spermatozoa per egg was 17 to 87%, with an overall mean of 65%. Sperm concentrations of 5.0 x 10(4)/egg exhibited a lower, 16.6% (P < 0.05) fertilization rate than higher sperm concentrations (1.25 x 10(5) to 1.20 x 10(8)/egg). Batches of 450, 2,000, 5,000, 8,000 and 11,000 eggs were similarly fertilized with various sperm concentrations. Mean fertility rate ranged from 25 to 67%, with an overall mean of 53%. The largest egg mass produced the lowest (P < 0.05) fertilization rate. A combination of 450 eggs per batch and 5.0 x 10(5) to 1.20 x (8) sperm per egg produced the highest rate of fertilization (67 to 87%).

Journal Article↗

PubMed1993

The hemizona assay: its role in identifying male factor infertility in assisted reproduction.

OBJECTIVES: To identify male factor infertility among a group of patients in an assisted reproductive program (phase 1) and to evaluate the hemizona assay (HZA) in the diagnosis and prognosis of such a program (phase 2). DESIGN: The IVF performance of normal gametes in the Tygerberg program were critically evaluated. Female patients were classified as pure tubal factor infertility, having a normal FSH:LH ratio on day 3 of the menstrual cycle. All participating women produced three or more preovulatory oocytes at retrieval and were inseminated with sperm considered normal by all present diagnostic criteria. The total and normal fertilization rate thresholds were defined in that group. Using those thresholds, couples tested for sperm binding in the HZA (n = 48) were used and divided into two groups according to their fertilization rates, namely group 1, low fertilization (< 55%) and group 2, normal fertilization (> 55%). SETTING: University-based tertiary care center. PATIENTS: Ninety-nine couples (589 oocytes) with pure tubal factor infertility and normal male factor were used in phase 1. Forty-eight couples with normal and abnormal male factors that had both HZA performed and IVF treatment were included in phase 2. RESULTS: Investigation of the performance of normal gametes in 99 couples (589 oocytes) revealed the total fertilization rate (total number of oocytes fertilized/total number of oocytes inseminated) was (mean +/- SD) 88.6% +/- 16.8% and the normal fertilization rate (total number of oocytes with normal fertilization/total number of oocytes inseminated) was 81.3% +/- 22%. The minimum total fertilization rate that can be considered normal in the Tygerberg program using mean--2 SD is therefore 55% and for normal fertilization rate is 37%. The group with low fertilization rate (< 55%) showed a mean hemizona index (HZI) significantly lower; nevertheless, the distribution overlapping indicates a low discriminating power of the HZA. A sensitivity of 75% and a specificity of 75% were found; the positive and negative predictive values were 81% and 68%, respectively. CONCLUSIONS: The results indicated the HZA and HZI contribute important information and can serve in conjunction with other semen characteristics as useful tools during the diagnosis of the male factor in assisted reproduction.

Chorionic Gonadotropin↗

PubMedDate not supplied

The importance of computer-assisted semen analysis and sperm function testing in an IVF program.

OBJECTIVE: To study the relationship of sperm motion characteristics, sperm morphology, and hypo-osmotic swelling test with fertilization rates in vitro. DESIGN: Computer-assisted measures of fresh seminal and processed sperm preparations, sperm morphology, and hypo-osmotic swelling test results were assessed for predicting fertilization by step-wise regression analysis. SETTINGS: In vitro fertilization laboratory, department of infertility management, university affiliated-hospital. INTERVENTIONS: None. PATIENTS: One hundred and two couples who underwent IVF were studied. MAIN OUTCOME MEASURES: Computer-assisted sperm motion variables in semen and following semen processing in capacitating media; hypo-osmotic swelling of sperm tails before and after semen processing; morphology of sperm before and after processing; fertilization of oocytes as evidenced by presence of two pronuclei as the end point. RESULTS: Various sperm motion parameters, hypo-osmotic swelling test results, and normal morphology of sperm were directly correlated to fertilization as judged by the Karl-Pearsons test. However, in step-wise regression analysis, normal morphology of sperm from seminal fraction exhibited 61% correlation with fertilization rates (P < .001). In step 2, normal morphology along with percent motility exhibited a 64% correlation with fertilization rates (P < .001). In step 3, normal morphology, percent motility, and linearity showed a 67% correlation with fertilization rates (P < .001). The hypo-osmotic swelling test did not predict fertilization rates (regression coefficient = 0.066, P = 0.474). In the processed sample preparations, normal sperm morphology showed a 72% correlation with fertilization rate (P < .001). In step 2, normal morphology along with curvilinear velocity exhibited a 77% correlation with fertilization rates (P < .001). In step 3, normal morphology, curvilinear velocity, and average path velocity showed a 79% correlation with fertilization rates (P < .001). The hypo-osmotic swelling test did not predict fertilization rates (regression coefficient = 0.076, P = 0.512). CONCLUSIONS: Morphology of sperm and computer-assisted sperm motion variables, such as motility, linearity, curvilinear velocity, and average path velocity, may serve as prognostic indicators for fertilization potential of sperm. The hypo-osmotic swelling test may describe only physiological intactness, rather than the fertilization potential of sperm. The results suggest that objective analysis of sperm motion characteristics and precise sperm morphology may form a first, and obligatory, step for critical evaluation of patients before they start IVF treatment.

Fertilization in Vitro↗

PubMed1995

Birth statistics 1993.

The key birth statistics for 1993, in Table E of the Annual Review on page 7 of this volume, show that: The total number of live births fell for the third consecutive year and was 673 thousand in 1993, 2 per cent fewer than in 1992, and the lowest annual total since 1986. The number of women in reproductive ages changed only marginally, so that the crude birth rate (CBR), the general fertility rate (GFR) and total period fertility rate (TPFR) each decreased. The TPFR was 1.76 in 1993, 2 per cent lower than in 1992. The mean age of women at childbirth continued to rise, and reached 28.1 years. The proportion of births outside marriage increased by a further 1 per cent between 1992 and 1993, to reach 32.2 per cent. There were 105.6 male births for every 100 female births--a higher ratio than in 1992.

Adult↗

PubMed2003

Sperm supply and egg fertilization in the ostrich (Struthio camelus).

We used egg break-out and spermatozoa trapped in the perivitelline layer of eggs to test the hypothesis that sperm supply and egg fertilization rate are high in the ostrich. Egg fertilization status was determined at break-out by the appearance of the germinal disc (GD) and then the perivitelline layer overlying the GD region was collected to count sperm (SpermOPVL) under fluorescence following staining with 4',6'-diamidino-2-phenyindole (DAPI). The study was carried out on commercial ostrich farms over two laying seasons. In the first year, 229 eggs from nine randomly chosen ostrich pens comprising pairs, trios (two females, one male) and larger groups were collected for 1 week of every month of laying. Eggs contained 253 +/- 18 SpermOPVL/mm2 of the GD (mean +/- SEM; range 0-1330). Egg fertilization rate averaged 89.4 +/- 3.4% and varied from 78.6 to 98.2% between pens. Month had no effect on sperm supply or egg fertilization status. Eggs from paired birds (sex ratio 1 : 1) had less sperm in the GD than the eggs from pens with a higher sex ratio. In the second year, 150 eggs from seven pens, each containing only one male and either one, two or three females, were studied for 2 weeks at the beginning (winter), middle (spring) and end (summer) of laying. Eggs contained 364 +/- 45 SpermOPVL/mm2 of the GD (range 0-2880). Season had no effect on sperm supply or egg fertilization. The number of SpermOPVL varied between pens, assumed to be due to variation between individual males. The number of SpermOPVL increased as the sex ratio increased only when very high-ranking males were excluded from the analysis. Egg fertilization rate was 94.4 +/- 3.1% but varied from 64.0 to 100% between pens. Egg fertilization was not affected by season or sex ratio. Low fertilization rates were observed in two pens and appeared related to the lack of synchrony between timing of laying and sperm production in the first, and lack of mating in the second pen. We conclude that ostrich flocks generally have high rates of egg fertilization and any infertility is associated with lack of sperm supply.

Animals↗

PubMed2006

Efficiency of oocyte cryopreservation: a meta-analysis.

OBJECTIVE: To determine the efficiency of oocyte cryopreservation relative to IVF with unfrozen oocytes. DESIGN: Meta-analysis. SETTING: Academic assisted reproduction center. PATIENT(S): Results of all reports from January 1997 to June 2005 with the patients undergoing IVF-intracytoplasmic sperm injection (ICSI) with cryopreserved cycles between 1996 and 2004 were compared with those of patients who underwent IVF-ICSI with unfrozen oocytes in 2002 and 2003 in our program. INTERVENTION(S): Mean age and number of ET cycles originating from unfrozen oocytes was matched with those for thaw cycles originating from oocytes cryopreserved with a slow-freezing (SF) protocol. Vitrification (VF) reports were not included in the comparative analysis because of a small number of pregnancies (10) before June 2005. MAIN OUTCOME MEASURE(S): The comparison of fertilization rate, clinical pregnancy, and live-birth rates per injected oocyte, clinical pregnancy and live-birth rates per transfer, and implantation rate between IVF-ICSI cycles with frozen and unfrozen oocytes. RESULT(S): Live-birth rates per oocyte thawed were 1.9% and 2.0% for SF and VF, respectively, before June 2005. Live-birth rates per injected oocyte and ET, respectively, were 3.4% and 21.6% for SF and were 6.6% and 60.4% for IVF with unfrozen oocytes. Compared to women who underwent IVF after SF, IVF with unfrozen oocytes resulted in significantly better rates of fertilization (odds ratio [95% confidence interval]); 2.22 (1.80, 2.74), of live birth per injected oocyte; 1.5 (1.26, 1.79), and of implantation; 4.66 (3.93, 5.52). These odds ratios were lower when oocyte cryopreservation success rates from 2002-2004 were compared with those for IVF with unfrozen oocytes. When the reports after June 2005 were considered, this trend did not appear to continue. With the consideration of VF reports after June 2005, however, higher pregnancy rates were achieved. CONCLUSION(S): In vitro fertilization success rates with slow-frozen oocytes are significantly lower when compared with the case of IVF with unfrozen oocytes. Although oocyte cryopreservation with the SF method appears to be justified for preserving fertility when a medical indication exists, its value for elective applications remains to be determined. Pregnancy rates with VF appear to have improved, but further studies will be needed to determine the efficiency and safety of this technique.

Cryopreservation↗

PubMed1995

Sperm preparation for intracytoplasmic injection: methods and relationship to fertilization results.

Sperm preparation for intracytoplasmic sperm injection (ICSI) is described and the effect of high speed centrifugation during preparation on fertilization rate is evaluated. No significant differences were found in the 2-pronuclear or abnormal fertilization rates between sibling oocytes injected with sperm prepared by swim-up or mini-Percoll combined with high speed centrifugation. The high fertilization rate obtained with both methods indicates that high speed centrifugation is not necessary to prepare sperm for ICSI. Fertilization rates were also compared for sperm obtained from ejaculates, fresh and frozen epididymal aspirates, and testicular biopsies. High fertilization rates were obtained from all groups but they were significantly higher in those oocytes injected with epididymal sperm (78% per oocyte surviving injection). The high fertilization rate with epididymal sperm may reflect sperm quality or may result from the method of sperm preparation for injection. Fertilization after the injection of sperm from which the tail was dislodged during immobilization was compared with that obtained using intact sperm. A significantly lower rate of 2-pronuclear fertilization was found in those oocytes injected with sperm heads only (55%) compared with intact sperm (68%), although cleavage rates between the two groups were similar. The use of hypo-osmotic medium to select potentially live sperm from an immotile sample is also described and fertilization was obtained after the injection of sperm with a structural defect which were selected using this technique. These results indicate that high fertilization rates can be obtained with ejaculated, epididymal and testicular sperm without special treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Cell Separation↗

PubMed2002

Births: preliminary data for 2001.

OBJECTIVES: This report presents preliminary data for 2001 on births in the United States. U.S. data on births are shown by age, race, and Hispanic origin of mother. Data on marital status, prenatal care, cesarean delivery, and low birthweight are also presented. METHODS: Data in this report are based on more than 96 percent of births for 2001. The records are weighted to independent control counts of all births received in State vital statistics offices in 2001. Comparisons are made with 2000 final data. RESULTS: The number of births, the crude birth rate, and the fertility rate all declined slightly between 2000 and 2001. The number of births was down by less than 1 percent, the crude birth rate declined 1 percent to 14.5 per 1,000 population, and the fertility rate was down slightly to 67.2 births per 1,000 women aged 15-44 years. Teenagers were less likely to give birth in 2001; the teen birth rate continued to fall, dropping 5 percent between 2000 and 2001 to 45.9 births per 1,000 females aged 15-19 years, another record low. The teen birth rate has fallen 26 percent since 1991. The birth rate for teenagers 15-17 years fell 8 percent, and the rate for teenagers 18-19 years was down 4 percent for 2000-2001. Since 1991 rates have fallen 35 percent for teenagers 15-17 years, and 20 percent for teenagers 18-19 years. Birth rates for women aged 20-24 declined by 2 percent, whereas rates for women 25-44 years increased. Childbearing among women aged 40-54 years was stable. The birth rate for unmarried women decreased modestly to 44.9 births per 1,000 unmarried women 15-44 years in 2001, still remaining below the peak reached in 1994. The number of births to unmarried women was up very slightly, but births to unmarried teens were down. The proportion of women who began prenatal care in the first trimester of pregnancy improved slightly to 83.4 percent, but the rate of low birthweight held at 7.6 percent. The total cesarean delivery rate jumped 7 percent between 2000 and 2001 to 24.4 percent of all births, the highest level ever reported from this data source; the primary rate of cesarean deliveries rose 5 percent, and the rate of vaginal births after previous cesarean delivery tumbled 20 percent.

Adolescent↗

PubMed1993

Family formation in the Czech and Slovak Republics.

The author analyzes family formation trends in the Czech and Slovak Republics. Information is included on first marriage rates, divorce, remarriage, and fertility. "Procreative behaviour in each of the birth-cohorts in the Czech Republic (starting with the birth-cohort 1930) is at the level of simple reproduction. In Slovakia, the completed fertility rate continued declining so that today the two parts of the former federation show very similar levels of reproduction. Marriage is a very wide-spread institution in Czechoslovakia and it is situated in the younger age groups.... The popularity of legal unions in the Czech and Slovak Republics and the relatively higher fertility rate in the European context can be ascribed to the young age at which those events occur." (SUMMARY IN CZE)

Birth Rate↗