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Biomedical subjects

Christina Bergh

Publications and source records attributed to Christina Bergh.

25 records · Page 2Linked to original sources

Derivation, characterization, and differentiation of human embryonic stem cells.

The derivation of human embryonic stem (hES) cells establishes a new avenue to approach many issues in human biology and medicine for the first time. To meet the increased demand for characterized hES cell lines, we present the derivation and characterization of six hES cell lines. In addition to the previously described immunosurgery procedure, we were able to propagate the inner cell mass and establish hES cell lines from pronase-treated and hatched blastocysts. The cell lines were extensively characterized by expression analysis of markers characteristic for undifferentiated and differentiated hES cells, karyotyping, telomerase activity measurement, and pluripotency assays in vitro and in vivo. Whereas three of the cell lines expressed all the characteristics of undifferentiated pluripotent hES cells, one cell line carried a chromosome 13 trisomy while maintaining an undifferentiated pluripotent state, and two cell lines, one of which carried a triploid karyotype, exhibited limited pluripotency in vivo. Furthermore, we clonally derived one cell line, which could be propagated in an undifferentiated pluripotent state.

Animals↗

Fallopian tube sperm perfusion: the impact of sperm count and morphology on pregnancy rates.

BACKGROUND AND OBJECTIVE: To evaluate the effect of changed criteria for sperm count and morphology when performing fallopian tube sperm perfusion (FSP) in unexplained infertility. PATIENTS AND METHODS: We report on a longitudinal study in which two periods of insemination cycles are compared. One hundred and eighty-three couples who started 361 stimulation cycles intended for FSP were included in the first period and 190 couples starting 303 cycles in the second period. The sperm requirement in the first study period was at least 7 million sperm in the prepared test sample. The FSP cycle included downregulation, controlled ovarian hyperstimulation (COH), ovulation induction and intrauterine and intrafallopian tube insemination using a sperm suspension of 3 mL volume. To avoid high-order multiple pregnancies, cycles at risk were converted to in vitro fertilization (IVF). Based on the results from the first period, sperm requirements were lowered to a sperm count of 3 million and at least 5% normal morphology according to strict criteria. RESULTS: FSP was performed in 51% and 60% of started cycles during the two periods with similar pregnancy (24% and 23%) and birth (15% and 19%) rates. Neither sperm count nor morphology above the requirements affected pregnancy rates. IVF-converted, completed cycles reached equal pregnancy (41%) and delivery (32%) rates in both periods. Multiple pregnancy rates were higher after IVF (38%) than after FSP (24%). CONCLUSION: The lowered requirements for sperm count and morphology have not impaired pregnancy results after FSP. Patients who either completed an FSP cycle or had their cycle converted to IVF were all at high risk of multiple pregnancy.

Fallopian Tubes↗

Cumulative probability of live birth after three in vitro fertilization/intracytoplasmic sperm injection cycles.

OBJECTIVE: To assess the probability of live birth after three available in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI) cycles. DESIGN: Retrospective, observational study. SETTING: University hospital. PATIENT(S): Nine hundred seventy-four couples who started their first conventional IVF or ICSI cycle between January 1996 and December 1997. A total of 1985 stimulated cycles were initiated. INTERVENTION(S): Analysis of the cumulative live birth rate using the life-table approach with and without taking dropouts into account. MAIN OUTCOME MEASURE(S): Cumulative live birth rate. RESULT(S): The overall cumulative live birth rate after three completed stimulated cycles (including freezing/thawing cycles) was 65.5% with an "optimistic" approach. For the "realistic" and "pessimistic" approaches the corresponding figures were 63.1% and 55.5%, respectively. Unexpectedly, 65% of couples not achieving a live birth interrupted the full treatment program of three cycles. CONCLUSION(S): The cumulative live birth rate gives the couple a more accurate prognosis of achieving a live birth after IVF/ICSI than the statistics usually provided. With the "realistic" estimation, 63% of the couples achieved childbirth after three available conventional IVF or ICSI cycles. Further studies are required to investigate the high drop-out rate.

Adult↗

Obstetric outcome and follow-up of children born after in vitro fertilization (IVF).

In vitro fertilization (IVF) is a well established and effective method for the treatment of infertility, but there is concern about the health of children born as a result of this procedure. The introduction of new technologies, such as intracytoplasmic sperm injection (ICSI), has increased concern that the offspring from such techniques may be at increased risk, particularly of malformations. Studies on obstetric and neonatal outcome and early infant development after IVF obtained from a Medline search were reviewed. Children born after IVF had a considerably higher risk of being born pre-term and with a lower birth weight than children conceived naturally. A high incidence of multiple births and maternal characteristics were the main factors responsible for the increase in adverse outcome. Novel strategies in assisted reproduction, including the development of single embryo transfer regimens and avoidance of multiple births, are required. There is also a need for further developmental follow-up of children born after assisted conception, especially those born after ICSI.

Journal Article↗