不妊症で妊娠した児は未熟児や周産期死亡の危険が増加する　

1999/5/21ロイター　　イギリスの研究によると自然妊娠による周産期死亡は1000人の児に対して9人であるが、不妊症を経験した人の妊娠では1000人に対して27人であった。多くは早産による危険であるが、全体的に不妊症の婦人は生殖機能問題を生じやすいらしい。

Risk of preemies, newborn death in infertile women

NEW YORK, May 21 (Reuters Health) -- Women with a history of infertility may be at increased risk of having their infants die during or soon after delivery, researchers report.
``Counselling for women before any form of infertility treatment should include discussion of the risks of perinatal (during or in the week following delivery) death,'' write researchers led by Dr. Elizabeth S. Draper of Leicester University in the UK. The findings are published in the May 22nd issue of The Lancet.
The investigators compared rates of infertility (treated or untreated) in 542 women who delivered either a stillborn infant or an infant who died within the first week of life, to rates in a ``control'' group of nearly 1,000 mothers of surviving newborns.
A full 10% of mothers who had lost an infant had a previous history of infertility, according to the authors, compared with just 3.5% of mothers whose infants survived.
In an interview with Reuters Health, Draper noted that some women who had been infertile ``manage to achieve a spontaneous pregnancy'' without the assistance of infertility treatment. She pointed out that, ``these women have a similar risk of losing their baby as those who've had infertility treatment and a resulting pregnancy.''
The study authors note that ``for women who experience infertility, our study suggests a risk of perinatal death of 27 per 1,000 births and a risk of perinatal death after successful infertility treatment of 23 per 1,000 births. This compares with a risk of perinatal deaths of 9 per 1,000 births in the overall population... indicating that for women who experience infertility this risk increases by about 18 per 1,000 births.''
The majority of perinatal deaths in women with a history of infertility were associated with single births and were linked to premature delivery. ``This finding supports the idea that these women had poor overall reproductive function,'' Draper and colleagues conclude.
In a commentary, Dr. Donna Day Baird of the National Institute of Environmental Health Sciences in Research Triangle Park, North Carolina, and colleagues elsewhere suggest that future research focus on ``exposures and underlying biological mechanisms that can cause both infertility and preterm birth.'' They conclude that ``the possibility that (infertility) treatment can lead to preterm birth, independently of multiple fetuses, needs further examination,'' they conclude.
SOURCE: The Lancet 1999;353:1724-1725, 1746-1749.