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K G Nygren

Publications and source records attributed to K G Nygren.

At least 19 recordsLinked to original sources
PubMed2006

Assisted reproductive technology in Europe, 2002. Results generated from European registers by ESHRE.

European results of assisted reproductive techniques (ART) from treatments initiated during 2002 are presented in this sixth report. Data was mainly collected from already existing national registers. From 25 countries, 631 clinics reported 324,238 treatment cycles with: IVF 122,634, ICSI 135,048, frozen embryo replacement (FER) 57 162, egg donation (ED) 7677, preimplantation genetic diagnosis/screening (PGD/PGS) 1563 and in vitro maturation (IVM) 154. Overall this represents a 12% increase since year 2001. For the second time, results on European data on intrauterine inseminations were reported from 17 countries. A total of 93,284 cycles [IUI-husband/partner (H), 78 505 and IUI-donor (D), 14,779] were included. In 13 countries where all clinics reported to the register, a total of 177,429 cycles were performed in a population of 193.7 million, corresponding to 916 cycles per million inhabitants. For IVF the clinical pregnancy rate per aspiration and per transfer was 26.0 and 29.5%, respectively. For ICSI the corresponding rates were 27.2 and 29.4%. These figures are marginally better than in 2001. After IUI-H the clinical pregnancy rate was 11.6% in women below 40 and 7.8% in women>or=40 years of age. After IVF and ICSI the distribution of transfer of 1, 2, 3 and 4 or more embryos was 13.7, 54.8, 26.9 and 4.7%, respectively. Compared with year 2001, less embryos were transferred, but huge differences existed between countries. The distribution of singleton, twin and triplet deliveries for IVF and ICSI combined was 75.5, 23.2 and 1.3%, respectively. This gives a total multiple delivery rate of 24.5%, compared with 25.5% in year 2001. The range of triplet deliveries after IVF and ICSI varied from 0.0 to 5.2% between countries. After IUI-H in women below 40 years of age, 10.2% were twin and 1.3% triplet gestations.

Adult↗
PubMed2005

Assisted reproductive technology in Europe, 2001. Results generated from European registers by ESHRE.

European results of assisted reproductive techniques from treatments initiated during 2001 are presented in this fifth report. Data were collected mainly from already existing national registers. From 23 countries, 579 clinics reported 289 690 cycles with: IVF 120 946, ICSI 114 378, frozen embryo transfer (FER) 47 195 and egg donation (ED) 7171. Overall this represents a 4% increase since the year 2000. For the first time, results on European data on intra-uterine inseminations (IUIs) were reported from 15 countries. A total of 67 124 cycles [IUI husband'sperm (IUI-H) 52 949 and IUI donor sperm (IUI-D) 14 185] were included. In 12 countries where all clinics reported to the register, a total of 108 910 cycles were performed in a population of 131.4 million, corresponding to 829 cycles per million inhabitants. For IVF, the clinical pregnancy rate per aspiration and per transfer was 25.1 and 29.0%, respectively. For ICSI, the corresponding rates were 26.2 and 28.3%. These figures are similar to the results from 2000. After IUI-H, the clinical pregnancy rate was 12.8% in women <40 and 9.7% in women > or =40 years of age. After IVF and ICSI, the distribution of transfer of one, two, three and > or =4 embryos was 12.0, 51.7, 30.8 and 5.5%, respectively. Compared with the year 2000, fewer embryos were transferred, but huge differences existed between countries. The distribution of singleton, twin and triplet deliveries for IVF and ICSI combined was 74.5, 24.0 and 1.5%, respectively. This gives a total multiple delivery rate of 25.5%, compared with 26.9% in the year 2000. The range of triplet deliveries after IVF and ICSI differed from 0.0 to 8.2% between countries. After IUI-H in women <40 years of age, 10.2% were twin and 1.1% were triplet gestations.

Age Distribution↗
PubMed2005

In vitro fertilisation in Sweden: obstetric characteristics, maternal morbidity and mortality.

OBJECTIVE: To investigate obstetric characteristics, maternal morbidity and mortality among Swedish women giving birth after in vitro fertilisation (IVF) treatment. DESIGN: Register study. SETTING: Nationwide study in Sweden. SAMPLE: All women known to have had IVF in Sweden 1982-2001. METHODS: Using Swedish health registers, women who had given birth after IVF were identified from all Swedish IVF clinics and compared with all women who gave birth. Analysis was performed with the Mantel-Haenszel technique. MAIN OUTCOME MEASURES: Diagnoses during pregnancy, at delivery and at re-admission within 60 days after delivery and risk of cancer. RESULTS: IVF women had an increased risk of bleeding in early pregnancy [odds ratio (OR) = 4.59, 95% confidence interval (95% CI) 4.08-5.15] and of ovarian torsion during pregnancy (OR = 10.6, 5.69-10.7). They were also more likely to encounter pre-eclampsia (OR = 1.63, 1.53-1.74), placental abruption (2.17, 1.74-2.72), placenta praevia (3.65, 3.15-4.23), bleeding in association with vaginal delivery (1.40, 1.38-1.50) and premature rupture of membranes (PROM) (2.54, 2.34-2.76). Interventions including caesarean sections (1.38, 1.32-1.43) and induction of labour (1.37, 1.29-1.46) in singleton pregnancies was more frequent. The type of IVF method had little effect on these results, but there was a tendency for women who had received intra-cytoplasmatic sperm injection (ICSI) to have slightly fewer complications than women having standard IVF. There was a significant decrease in cancer risk after IVF (0.79, 0.69-0.91) but a suggested increase in the risk of ovarian cancer both before (2.70, 1.49-4.91) and after (2.08, 1.15-3.76) IVF. No change in mortality was observed. CONCLUSIONS: Women treated with IVF had an increased obstetric morbidity. This seems to contribute little to the well-known increased risk of preterm delivery.

Adult↗
PubMed2005

Avoidance of multiple pregnancy by use of single embryo transfer.

The benefits of single embryo transfer (SET) for both mother and child are evident. Already twin pregnancies constitute a relatively serious problem exemplified by the incidence of cerebral palsy, which will increase significantly as well as a risk for premature birth. Selective embryo reduction in countries where this is allowed may be one way to acutely solve the situation. In the beginning the use of natural cycle in vitro fertilization (IVF) avoided the problem, but with the introduction of controlled ovarian hyperstimulation predominantly by use of gonadotrophins in the early 1980ies the temptation to replace more than 1 embryo at a time became too strong. SET with maintenance of acceptable pregnancy rates can only be achieved if tools (improved morphological criteria, biomarkers, preimplantation genetic screening) to select the most viable/normal embryos are at hand together with improved cryopreservation procedures. In reports from Finland and Belgium already 5 years ago, elective single embryo transfer (eSET) was shown to reach almost the same success rates as double embryo transfer (DET) in selective patient groups (age under 37, good quality embryos). The indications for eSET have increased during the last years. In Finland the initiative came from the IVF clinics while in Sweden a legislative process (in act from January 2003) resulted in the recommendation that eSET should be used in the vast majority of the IVF cycles. In both these Nordic countries around 60% of the transfers are today eSET and the multiple pregnancy rate below 10% with no triplets. From an economical point of view, it is of course evident that multiple pregnancies with the numerous potential complications should be avoided altogether. Countries where IVF is included in the government health insurance will thus most likely show the way towards an even more successful, safer and cheaper treatment of infertile couples in the future.

Embryo Disposition↗
PubMed2004

Assisted reproductive technology in Europe, 2000. Results generated from European registers by ESHRE.

European results of assisted reproductive techniques from treatments initiated during 2000 are presented in this fourth annual report. Data were collected mainly from pre-existing national registers. From 22 countries, 569 clinics reported 279 267 cycles: IVF 126 961, ICSI 99 976, frozen embryo replacement (FER) 45 800 and oocyte donations (OD) 6530. In nine countries where all clinics reported to the register, a total of 142 174 cycles were performed in a population of 166 million, corresponding to 856 cycles per million inhabitants. After IVF and ICSI, the distribution of transfer of one, two, three and >or=4 embryos was 12.1, 46.7, 33.3 and 6.8%, respectively. Huge differences existed between countries. For IVF, the clinical pregnancy rate per aspiration and per transfer was 24.7 and 28.4%, respectively. For ICSI, the corresponding rates were 26,6% and 28,7%. These figures represent increases of 0.7 and 0.8% compared with 1999. The distribution of singleton, twin, triplet and quadruplet deliveries for IVF and ICSI combined was 73.6, 24.4, 2.0 and 0.04%. This gives a total multiple delivery rate of 26.4%. The range of triplet deliveries after IVF and ICSI ranged from 0.3 to 7.0% between countries. Compared with 1999, the number of reported cycles was increased by 8% and the clinical pregnancy rate per transfer was increased by 0.7% after IVF and by 0.8% after ICSI. The total multiple delivery rates after IVF and ICSI remain unchanged during the last 4 years.

Adolescent↗
PubMed2002

Neonatal outcome in pregnancies from ovarian stimulation.

OBJECTIVE: To study the neonatal outcome in pregnancies after ovarian stimulation, not including in vitro fertilization. The outcomes studied were multiple birth, preterm birth, and low birth weight among singletons, congenital malformations, and infant death. METHODS: We identified 4029 women who delivered between 1995-1999 after ovarian stimulation alone and compared them with 438,582 women who neither had ovarian stimulation nor in vitro fertilization. We controlled for the confounding effect of year of birth, maternal age, parity, and length of subfertility before the pregnancy. RESULTS: The twinning rate was 5.9% in the study group and 1.2% in the control group. The triplet rate was 0.5% in the study group and 0.02% in the control group. A nearly doubling of the rate of monozygotic twinning was indicated in the study group compared with the control group. There was an excess of singleton preterm births and low birth weight infants in the study group, but this was mainly explainable by confounding of maternal age, parity, and subfertility. The rates of congenital malformations and perinatal deaths were increased, also mainly explainable by maternal characteristics. No increase in specific types of congenital malformations was seen. CONCLUSION: As the deviations in neonatal outcome after ovarian stimulation alone were reduced or disappeared when the confounding of maternal age, parity, and subfertility was taken into consideration, there is probably little direct effect of the stimulation procedure as such.

Adult↗
PubMed2002

Assisted reproductive technology in Europe, 1999. Results generated from European registers by ESHRE.

European results of assisted reproductive techniques from treatments initiated during 1999, are presented in this third report. Data were collected mainly from pre-existing national registers. From 22 countries 538 clinics reported 258 460 cycles: IVF 125 370, ICSI 95 221, frozen embryo replacement (FER) 34 002 and oocyte donations (OD) 3867. In eight countries, where all clinics reported to the register, a total of 99 629 cycles was performed in a population of nearly 106 million, corresponding to 943 cycles per million inhabitants and 3.9 cycles per 1000 women aged 15-49 years. After IVF and ICSI the distribution of transfer of 1, 2, 3 and >or=4 or more embryos was 11.9, 39.2, 39.6 and 9.3% respectively. Huge differences existed between countries. For IVF the clinical pregnancy rate per aspiration and per transfer was 24.2 and 27.7% respectively. For ICSI the corresponding rates were 26.1 and 27.9%. These figures represent relative increases by 2.2 to 5.2% compared with 1998. The distribution of singleton, twin, triplet and quadruplet deliveries for IVF and ICSI combined was 73.7, 24.0, 2.2 and 0.1%. This gives a total multiple delivery rate of 26.3%. Triplet deliveries after IVF and ICSI ranged from 0.3-7.0% between countries. Compared with 1998, the number of reported cycles increased by 11% and the clinical pregnancy rate per transfer increased from 27.0 to 27.7% after IVF and from 26.8 to 27.9% after ICSI. Multiple deliveries after IVF and ICSI remained unchanged at 26.3% in 1999.

Adolescent↗
PubMed2002

Hospital care utilization of infants born after IVF.

BACKGROUND: Infants born after IVF are often twins, and singleton IVF babies have an increased risk for preterm birth. Both conditions are likely to increase morbidity. We examined the frequency and duration of hospitalization required by babies born after IVF, and compared this information with all infants born in Sweden during the same time period. METHODS: We used a nationwide registration of IVF pregnancies from 1984 to 1997 and a nationwide register of all in-patient care up to the end of 1998. We identified 9056 live born infants after IVF treatment and compared them with 1 417 166 non-IVF live born infants. RESULTS: The highest odds ratio (OR approximately 3) was seen for neonatal hospitalization, but an increased OR (1.2-1.3) was noted for children up to 6 years of age. The OR for being hospitalized after IVF was 1.8, but when the analysis was restricted to term infants it was 1.3 and this excess was then explainable by maternal subfertility. Statistically significant increased ORs were seen for hospitalization for cerebral palsy (1.7), epilepsy (1.5), congenital malformation (1.8) or tumour (1.6), but also for asthma (1.4) or any infection (1.4). When information from the Swedish Cancer Registry was used, no excess risk for childhood cancer was found. The average number of days spent in hospital by IVF and non-IVF children was 9.5 and 3.6 respectively. CONCLUSIONS: The increased hospitalization of IVF children is, to a large extent, due to the increased incidence of multiple births. Therefore, the increased costs associated with this may be reduced by the use of single embryo transfers, with the savings in health care costs being offset against the increased number of embryo transfer cycles required to maintain the pregnancy rate.

Birth Rate↗
PubMed2001

Assisted reproductive technology in Europe, 1998. Results generated from European registers by ESHRE. European Society of Human Reproduction and Embryology.

European results of assisted reproductive techniques from treatments initiated during 1998 are presented in this second ESHRE report. Data was collected from 18 European countries usually from pre-existing national registers. A total of 521 clinics from these 18 countries reported 232 443 cycles: IVF 103 919 intracytoplasmic sperm injection (ICSI) 89 192 unclassified fertilization method 667 frozen embryo replacement (FER) 34 03 oocyte donations (OD) 4629. In nine countries where all clinics reported to the register a total of 128 801 cycles were performed in a population of 165 million corresponding to 781 cycles per million inhabitants 3.2 cycles per 1000 women aged 15-49 years. After IVF ICSI the distribution of transfer of 1, 2, 3 > or =4 embryos was 11.5, 37.2, 42.0 and 9.4% respectively. Huge differences existed between countries. For IVF the clinical pregnancy rate per aspiration per transfer was 23.2% 27.0% respectively. For ICSI the corresponding rates were 24.8% 26.8%. The distribution of singleton, twin, triplet, quadruplet deliveries for IVF and ICSI combined was 73.7, 23.9, 2.3 and 0.1%. This gives a total multiple delivery rate of 26.3%. The range of triplet deliveries after IVF and ICSI differed from 0.2-5.3% between countries. Compared with 1997, the number of reported cycles has increased by 14% and the number of reporting clinics by 8%. The clinical pregnancy rate per transfer increased from 26.1 to 27.0% after IVF and from 26.4 to 26.8% after ICSI. Multiple deliveries after IVF and ICSI decreased from 29.6 to 26.3%.

Adolescent↗
PubMed2001

Assisted reproductive technology in Europe, 1997. Results generated from European registers by ESHRE. European IVF-Monitoring Programme (EIM), for the European Society of Human Reproduction and Embryology (ESHRE).

European results of assisted reproductive techniques from treatments initiated during 1997 are presented in this first ESHRE report. Data were collected from 18 European countries, usually from already-existing national registers. A total of 482 clinics from these 18 countries reported 203 893 cycles. In 10 countries with complete registration, 133215 cycles were performed in a population of 174 million, corresponding to 765 cycles per million inhabitants. After IVF and intracytoplasmic sperm injection (ICSI), the distribution of transfer of one, two, three and four or more embryos was 11.5, 35.9, 38.4 and 14.3% respectively. Huge differences existed between countries. For IVF, the clinical pregnancy rate per transfer was 26.1%, and the delivery rate per embryo transfer 20.9%. For ICSI, the corresponding rates were 26.4% and 21.5%. Singleton, twin, triplet and quadruplet delivery rates for IVF were 70.4, 25.8, 3.6 and 0.2% respectively, giving a total multiple delivery rate for IVF of 29.6%. After ICSI, the corresponding rates were 71.7, 25.2, 2.9 and 0.1%, amounting to a total multiple delivery rate of 28.2%. The range of triplet delivery rates after IVF range from 0.4% to 11.9% among countries.

Embryo Transfer↗
PubMed1999

Deliveries and children born after in-vitro fertilisation in Sweden 1982-95: a retrospective cohort study.

BACKGROUND: In-vitro fertilisation is an effective treatment for infertility, but there is concern about the health of children. We investigated, in a retrospective registry study, malformations, cancers, and deaths in the complete Swedish in-vitro-fertilisation birth cohort compared with the general population. METHODS: We collected data from all in-vitro-fertilisation clinics in Sweden and compared the obstetric outcomes of babies (n=5856) born between 1982 and 1995 with all babies born in the general population (n=1,505,724) during the same period, according to data from the Swedish Medical Birth Registry and the Registry of Congenital Malformations. We investigated the incidence of childhood cancer through the Swedish Cancer Registry. Data were stratified for maternal age, parity, previous subfertility, year of birth, and multiple of pregnancies. FINDINGS: Multiple births occurred in 27% of pregnancies compared with 1% in the control group. In the in-vitro-fertilisation group, more babies were born preterm (<37 weeks) than controls (30.3 vs 6.3%) and more had low birthweights (<2500 g, 27.4 vs 4.6%). The perinatal mortality was 1.9% in the in-vitro fertilisation group and 1.1% in the controls. For in-vitro-fertilisation singletons, the risk ratios, adjusted for year of birth, for very preterm birth (<32 weeks) and very low birthweight (<1500 g) were 3.54 (95% CI 2.90-4.32) and 4.39 (3.62-5.32), respectively. Malformations occurred in 5.4% of all babies in the in-vitro-fertilisation group (1.39 [1.25-1.54]), and the rates of neural-tube defects and oesophageal atresia were higher than those in the controls. There was no increase in childhood cancer in the in-vitro-fertilisation group. INTERPRETATION: A high frequency of multiple births and maternal characteristics were the main factors that led to adverse outcomes, and not the in-vitro-fertilisation technique itself. The clinical practice of in-vitro-fertilisation needs to be changed to lower the rate of multiple pregnancy.

Cohort Studies↗
PubMed1996

The utilization rate and pregnancy outcome of multifetal pregnancy reduction in the Nordic countries.

OBJECTIVE: To review the utilization rate and pregnancy outcome of multifetal pregnancy reductions (MFR) in the Nordic countries during the period January 1986-June 1992. STUDY DESIGN: All centers offering assisted conception in Denmark, Finland, Norway and Sweden were retrospectively surveyed by means of a questionnaire with regard to the number and methods used for MFR, pregnancy loss and the outcomes of the pregnancies. The response rate was 100%. RESULTS: During the period studied, 185 births of triplets or higher multiples occurred in Sweden, 120 in Finland and 102 in Denmark. MFR was performed in 42 women (Sweden 26, Finland 10, Denmark 6) but not in Norway at all. This gives an estimated average utilization rate of 1/7 multiple births of three or more in Sweden, 1/17 in Denmark and 1/12 in Finland. The most frequently used method was intracardiac or intrathoracic injection of a potassium chloride solution in gestational weeks 9-12. One pregnancy was reduced from seven to four fetuses, two from five to three, 10 from five to two, one from four to three, 17 from four to two, one from four to one, five from three to two, four from three to one and one from two to one. Nine (21%) pregnancies terminated in a spontaneous abortion within one week (n = 2) to several weeks (n = 7) after the procedure. Of the remaining 33 (79%) pregnancies which continued to delivery, two fetuses died in utero in the second trimester, three infants died perinatally and one child had transverse limb reduction defects. A successful pregnancy defined by the discharge home of at least one infant occurred in 79% of the cases. CONCLUSION: This study gives national estimates on the utilization rate of MFR. Although MFR is performed more frequently in Sweden than in Denmark and Finland, the overall figures remain low in the Nordic countries. The incidence of pregnancy loss in this study is somewhat higher than in several larger reported series, probably reflecting the learning curve of the procedure. It seems reasonable that MFR should be performed in only a few centers in the Nordic countries.

Female↗