Further, as far back as 2006 the Institute of Medicine included "prior firsttrimesterabortion" on a list of risk factors associated with premature birth.6.
此外早在2006年之前，医学研究所的一份早产风险因素清单里包括首次妊娠时堕胎。
2
Randomized controlled trials comparing methods of pain control in firsttrimester surgical abortion at less than 14 weeks gestational age using electric or manual suction aspiration.
Blackmun then cited medical evidence suggesting that in the second trimester, an abortion posed a greater threat to a woman's health than one performed in the firsttrimester.