The clinical presentation of a threatened abortion describes any bleeding seen during pregnancy prior to viability, that has yet to be assessed further. At investigation it may be found that the fetus remains viable and the pregnancy continues without further problems. It has been suggested that bed rest improves the chances of the pregnancy continuing when a small subchorionic hematoma has been found on ultrasound scans.[1]
Alternatively the following terms are used to describe pregnancies that do not continue:
An empty sac is a condition where the gestational sac develops normally, while the embryonal part of the pregnancy is either absent or stops growing very early. Other terms for this condition are blighted ovum and anembryonic pregnancy.
An inevitable abortion describes where the fetal heart beat is shown to have stopped and the cervix has already dilated open, but the fetus has yet to be expelled. This usually will progress to a complete abortion.
An incomplete abortion occurs when tissue has been passed, but some remains in utero.[2]
A missed abortion is when the embryo or fetus has died, but a miscarriage has not yet occurred. It is also referred to as delayed miscarriage.
The following two terms consider wider complications or implications of a miscarriage:
A septic abortion occurs when the tissue from a missed or incomplete abortion becomes infected. The infection of the womb carries risk of spreading infection (septicaemia) and is a grave risk to the life of the woman.
Recurrent pregnancy loss (RPL) or recurrent miscarriage (medically termed habitual abortion) is the occurrence of 3 consecutive miscarriages. A large majority (85%) of women who have had two miscarriages will conceive and carry normally afterwards, so statistically the occurrence of three abortions at 0.34% is regarded as "habitual".[3]
Very early miscarriages - those which occur before the sixth week LMP (since the woman's Last Menstrual Period) are medically termed early pregnancy loss[4] or chemical pregnancy.[5] Miscarriages that occur after the sixth week LMP are medically termed clinical spontaneous abortion.[4]
In medical contexts, the word abortion refers to any process by which a pregnancy ends with the death and removal or expulsion of thefetus, regardless of whether it's spontaneous or intentionally induced. Many women who have had miscarriages, however, object to the term abortion in connection with their experience, as it is generally associated with induced abortions. In recent years there has been discussion in the medical community about avoiding the use of this term in favor of the less ambiguous term miscarriage.[6]
Labor resulting in live birth before the 37th week of pregnancy is termed premature birth, even if the infant dies shortly afterward. Although long-term survival has never been reported for infants born from pregnancy shorter than 21 weeks, infants born as early as the 16th week of pregnancy may cry and live a few minutes or hours.[7]
A fetus that dies while in the uterus after about the 20th week of pregnancy is termed a stillbirth. Premature births orstillbirths are not generally considered miscarriages, though usage of the terms and causes of these events may overlap.
↑Ben-Haroush A, Yogev Y, Mashiach R, Meizner I (2003). "Pregnancy outcome of threatened abortion with subchorionic hematoma: possible benefit of bed-rest?". Isr. Med. Assoc. J. 5 (6): 422–4. PMID12841015.CS1 maint: Multiple names: authors list (link)
↑Hutchon D, Cooper S (1998). "Terminology for early pregnancy loss must be changed". BMJ. 317 (7165): 1081. PMID9774309.
Hutchon D (1998). "Understanding miscarriage or insensitive abortion: time for more defined terminology?". Am. J. Obstet. Gynecol. 179 (2): 397–8. PMID9731844.