Miscarriage at 5 weeks

Miscarriage or abortion is defined by WHO (World Health Organization) as expulsion or extraction of a fetus or embryo weighing 500gm or less from its mother’s womb before 23 weeks of pregnancy. Overall, about 12–15% of pregnancies end in miscarriage, with the frequency increasing with rising maternal age.

Miscarriage and abortion are terms used interchangeably to describe a pregnancy loss during initial trimesters. However, most of the time the term miscarriage is attributed to an unplanned or spontaneous loss, whereas abortion is reserved for an induced termination of pregnancy.

Spontaneous miscarriage usually manifest with some form of vaginal bleeding, back pain, lower abdominal pain, or passing out tissue with or without blood clots. It’s presentation may vary between individuals and between its types. Sometimes there are no symptoms and the miscarriage is only diagnosed during an ultrasound examination which detects a fetus with an absent heart beat.

When a pregnant lady visits the doctor with symptoms of vaginal bleeding, lower abdominal pain or passing out blood clots with tissue; a vaginal examination and ultrasound test for fetal heart activity would be performed to determine the viability of her pregnancy. From these test, an obstetrician would be able to tell if her pregnancy is at threat or a miscarriage is inevitable. Sometimes, one does not experience the above mentioned symptoms. However, the sudden decrease in nausea, vomiting, and breast size which initially started with the onset of pregnancy are the clues to the diagnosis of a miscarriage.

One in every five pregnancies are complicated with threatened miscarriage. Threatened miscarriage occurs when you experiencing signs of miscarriage but ultrasound shows that the fetal heart beat is present. You may need a further scan in a week or two to check what’s happening. Fortunately, more than 90% of these cases will progress to full term. The outcome tend to be more favorable if you are below 35 years of age and have no previous history of miscarriage. Ultrasound scan showing a strong fetal heart activity and no discrepancy between weeks of pregnancy and fetal size are also good indicators.

A complete miscarriage means that the pregnancy has been miscarried although there might sometimes be residual blood or tissue in the womb. If the process of miscarriage has begun, but some of the pregnancy tissue is still found in the womb, the miscarriage is deemed incomplete.Your obstetrician would then recommend on conservative or surgical treatment, depending on the situation. Sometimes, there are no symptoms or signs of a miscarriage but fetal heart activity is absent during routine scanning, this is called missed miscarriage. For those who experience recurrent miscarriages, meaning 3 or more successive spontaneous miscarriage, investigation should be carried out to identify the cause.

Miscarriage can be attributed to fetal, or parent’s factor. The most common case of miscarriages is a mal-developed embryo (embryo with defects in the chromosomes), this would be nature’s own defense mechanism to avoid abnormal fetuses. Maternal factors play an important role in miscarriages as well. The product of conception might not be able to get a good grip on the walls of the uterus if your uterus is deformed or has scar tissues from pervious surgical interventions. A weak cervix that is unable to keep the opening of the uterus closed would also cause an abortion. Any abnormality in a pregnant mother’s immunity can also cause miscarriages.

Before the 5th week of pregnancy, the risk of miscarriage is 22-75%. Sometimes, you might be unaware that you have been pregnant since the miscarriage occured before your next menstrual cycle and your menses took place as usual. The risk is high because at this stage, the progress of pregnancy could be affected by factors such as failed implantation, defect during fertilization, chromosomal abnormalities within either or both of the egg and sperm, etc. Thankfully, the risk of miscarriage reduces dramatically with each passing week, by the 7th and 13th week of pregnancy, 2.5% and 1% of pregnancy are spontaneously aborted respectively in an average healthy woman. During this time, a heart beat should be detected via ultrasound and the risk of miscarriage drops dramatically as the baby has crossed a significant developmental milestone.

In conclusion, miscarriage risk falls with each passing week, with significant drops around the 7th week, and again after the 13th week mark. Your age, your partner’s age, and your number of prior miscarriages all affect your overall risk of miscarriage. Miscarriage risk rises dramatically after about age 37 for women, and age 40 for men.

References:

Definitions and indicators in family planning, maternal and child health and reproductive health. WHO Regional Strategy on Sexual and Reproductive Health. Geneva: World Health Organization, 2001.
Zinaman MJ, Clegg DE, Brown CC, O’Connor J, Selevan SG. Estimates of human fertility and pregnancy loss. Fertility and Sterility 1996;65: 503–509.
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC478228/
Tong S, Kaur A, Walker SP, Bryant V, Onwude JL, Permezel M. Miscarriage risk for asymptomatic women after a normal first-trimester prenatal visit. Obstet Gynecol. 2008 Mar;111(3):710-4.
Wilcox AJ, Weinberg CR, O’Connor JF, et al. Incidence of early loss of pregnancy. N Engl J Med. Jul 28 1988;319(4):189-94.
http://pregnancyloss.info/statistics/
http://www.ncbi.nlm.nih.gov/pubmed/12042293