In vitro fertilization (IVF) and twin pregnancy outcomes
Bibliographic record
Abstract
Background: IVF treatment has been used to transfer multiple embryos leading to multiple pregnancies which are known to be associated with increased maternal and perinatal complications. One question is whether IVF itself contributes to these risks. We compare the outcomes (maternal and perinatal) of IVF twin pregnancies with those of non-IVF twin pregnancies in the general population, in the province of British Columbia, Canada. We hypothesized twin pregnancies conceived by IVF are associated with a greater risk of maternal complications, abnormal labour and delivery events, and worse perinatal outcomes, compared with their non-IVF counterparts. Methods: An IVF twin pregnancy group (n = 161) was identified, in the former IVF Program of the University of British Columbia Centre for Reproductive Health (UBCCRH). We obtained these cases from the UBCCRH database between April 1, 1998, and March 31, 2010. A non-IVF twin pregnancy group was obtained by linking to the BC Perinatal Database to serve as a comparison group (n = 5525). Pregnancy outcomes and labour and delivery events were compared between IVF and non-IVF pregnancies using logistic and linear regression after adjustment for mothers' age, body mass index (BMI), and parity. Results: After adjustment for age, BMI, and parity, IVF twin pregnancies had higher rates of gestational hypertension, antepartum hemorrhage, gestational diabetes Mellitus, higher risks of C-section as the method of delivery and steroid use for lung maturation in IVF mothers. Also there were higher risks of IUGR and congenital anomalies in IVF babies, and IVF births had a lower birth weight, birth length, head circumference, and gestational age at birth. Conclusion: IVF twin pregnancies have an increased risk of some maternal complications, abnormal labour and delivery characteristics, and poorer perinatal outcomes, than naturally conceived twin pregnancies, even after adjustment for age, BMI, and parity. Further research is needed to clarify whether it is the infertility, maternal characteristics and co-morbidity associated with infertility, the IVF procedure or the potentially differential care of IVF patients that account for this increase in risk.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".