By Will Boggs, MD
A beating foetal heart four weeks after in vitro fertilisation (IVF) predicts successful completion of the first trimester of pregnancy.
"Early ultrasound, in the patient with no history of miscarriage, is a very good predictor of a viable pregnancy," Dr. Peter G. McGovern from the University of Medicine and Dentistry of New Jersey in Newark told Reuters Health.
McGovern and his colleagues measured foetal cardiac activity four weeks after IVF in 139 women undergoing fresh IVF cycles.
All but two gestational sacs with foetal cardiac activity - 51 out of 53 (96 percent) - completed the first trimester, the authors report, whereas 13 of 15 without foetal cardiac activity (87 percent) did not complete the first trimester.
Among the single foetus pregnancies, all with cardiac activity completed the first trimester, but all pregnancies without early foetal cardiac activity failed in the first trimester, according to the report in the journal Fertility & Sterility.
Similarly, for twin pregnancies, 15 out of 17 (88 percent) gestational sacs with foetal cardiac activity completed the first trimester, but three out of five (60 percent) without foetal cardiac activity did not. When each twin pregnancy was evaluated as a unit, all 11 completed the first trimester with at least one foetus.
Foetal cardiac activity was also highly predictive of live birth, the researchers say. Nearly 90 percent of the gestational sacs with foetal cardiac activity - 46 out of 53 (87 percent) - resulted in a live birth, whereas 14 out of 15 (93 percent) of gestational sacs without foetal cardiac activity did not result in a live birth.
Positive foetal cardiac activity predicted a live birth 89 percent of the time in single pregnancies. The positive predictive value of foetal cardiac activity for live birth in twins was 82 percent per gestational sac and 91 percent per pregnancy, the report indicates.
"We can counsel IVF patients without a history of recurrent miscarriage that a documented foetal heart rate at four weeks after oocyte (egg) retrieval (six weeks' gestational age) is highly predictive of successful completion of the first trimester, as well as of live birth," the investigators conclude.