Time to achieve pregnancy affects outcome

The time needed to achieve pregnancy appears to affect the outcome of that pregnancy, Swedish researchers report. In particular, time to pregnancy seems to affect the risks of Miscarriage, pregnancies in which the embryo implants outside of the womb, and multiple live births.

While the current findings support previous reports, studies that have compared the time to pregnancy with pregnancies ending in live births to the rate of pregnancies outside of the womb and stillbirths have, "to the best of our knowledge, never previously been performed," Dr. Anna Axmon and Dr. Lars Hagmar, from University Hospital in Lund, note.

The findings, which appear in the journal Fertility and Sterility, are based on a study of 5,302 pregnancies in three Swedish groups of women. The women were surveyed to determine the time to pregnancy.

Pregnancies ending in Miscarriage, both early and late, took longer to achieve than those ending in live births, the authors report. Likewise, the risk of pregnancies outside the womb was directly related to the time to pregnancy.

A spontaneous abortion is the loss of a fetus during pregnancy due to natural causes. The term "miscarriage" is the spontaneous termination of a pregnancy before fetal development has reached 20 weeks. Pregnancy losses after the 20th week are categorized as preterm deliveries.

The term "spontaneous abortion" refers to naturally occurring events, not elective or therapeutic abortion procedures.

Other terms include:

• missed abortion (a pregnancy demise where nothing is expelled)
  
• incomplete abortion (not all of the products of conception are expelled)
  
• complete abortion (all of the products of conception are expelled)
  
• threatened abortion (symptoms indicate a miscarriage is possible)
  
• inevitable abortion (the symptoms cannot be stopped, and a miscarriage will happen)
  
• infected abortion

By contrast, multiple live births were associated with shorter time to pregnancy. No relationship was seen between time to pregnancy and stillbirth.

Among pregnancies ending in a single live birth, the time to pregnancy was directly linked to the risk of preterm delivery, the report indicates.

Further studies are needed to shed light on the mechanisms involved in the association between time to pregnancy and pregnancy outcomes, the researchers conclude.

SOURCE: Fertility and Sterility, October 2005.