Obstetrics and Gynaecology Forum - Volume 24, Issue 1, 2014
Volume 24, Issue 1, 2014
Spoilt for choice? How to approach the subject of Down's syndrome screening with expecting parents : editorialAuthor Lut GeertsSource: Obstetrics and Gynaecology Forum 24, pp 1 –5 (2014)More Less
The risk of Down syndrome (DS; trisomy 21; T21) in the general population is about 1 in 500 in early pregnancy and 1 in 700 amongst live born babies and it is considered standard of care to offer DS screening to all pregnant women. Screening for DS has seen very significant improvements in the last two decades and this has lead to very high expectations from parents, as witnessed by the steep increase in medicolegal claims when a DS baby is born unexpectedly. At present, a plethora of tests is available to determine the risk for DS in an individual pregnancy and the newest test, as discussed in the paper by Urban et al. in this Journal, certainly adds another twist to this story.
Source: Obstetrics and Gynaecology Forum 24, pp 9 –13 (2014)More Less
Peripartum cardiomyopathy (PPCM) is often diagnosed and treated late due to a lack of awareness amongst health care workers. There are widespread definitions for peripartum cardiomyopathy, some with strict criteria that may cause some patients to be missed, leading to the proposal of a modified definition. The incidence varies highly between countries and in South Africa it appears to be around 1 in 1000 pregnancies. The precise pathophysiology remains unclear but new evidence points towards a prolactin-oxidative stress cascade. This may in future provide us with a disease specific therapeutic intervention. The clinical presentation is highly varied and the management is similar to management of any patient with heart failure, but in the pregnant patient the teratogenicity of drugs must be considered. Multidisciplinary input is needed especially when managing delivery of these patients. Delivery should take place in a high care area experienced in managing pregnant patients with cardiac disease. The prognosis of patients diagnosed with PPCM varies geographically with roughly a third of patients returning to normal cardiac function and a third showing partial recovery. All patients should be fully counselled about the risk of heart failure in subsequent pregnancies and effective contraception.
Source: Obstetrics and Gynaecology Forum 24, pp 15 –19 (2014)More Less
Several biological mechanisms have been proposed to link endometriosis with infertility. All of the current proposed mechanisms are clearly pathological in their own way, but none have been shown to directly decrease fecundity in women. The causal relationship between the presence of endometriosis and sub fertility is supported by several arguments as suggested by D'Hooghe et al.
Source: Obstetrics and Gynaecology Forum 24, pp 21 –24 (2014)More Less
Background : Endometriosis is common, affecting up to 10% of females in their reproductive years. The vast majority of sufferers present with pain and infertility. The etiology of endometriosis is thought to be due to retrograde menstruation and implantation of endometrial tissue onto visceral peritoneum outside the uterus. Anti-Mullerian hormone is produced by granulose cells within the primordial follicles, and represents the ovarian reserve. AMH levels decline with age; however there are multiple factors which may affect the level at any given point. Many women presenting to infertility clinics have ovarian endometriomas. Diagnosis : The gold standard diagnostic modality for endometriosis is laparoscopic inspection of the pelvis. A positive histological result of biopsied tissue will confirm endometriosis; however a negative histological result does not exclude the diagnosis. In the case of ovarian endometriomas, one may palpate a pelvic mass or see a mass originating from the adnexa on ultrasound examination. Excised endometriomas should be sent for histological examination to exclude rare forms of ovarian carcinoma. The positive predictive value of sonar in identifying ovarian endometriomas can be as high as 97% in the hands of an experienced sonographer. Treatment of ovarian endometriomas : Laparoscopic excision is considered the treatment of choice. Excision has many advantages compared to drainage alone. Medical therapy alone has a limited role in the treatment of endometriosis; however certain modalities do offer acceptable symptomatic relief but their cost and side effect profile can limit their long term use. It is evident that even in the hands of an experienced surgeon there is often accidental damage to normal ovarian tissue during laparoscopic excision of ovarian endometriomas. There are various techniques that can be used during laparoscopy to excise ovarian endometriomas, with the combined technique and the three-step management technique being superior. Surgery and AMH levels : The evidence of how surgery affects AMH levels is conflicting. Assessing the evidence has remained a challenge. Study methodology varies tremendously and study heterogenicity remains a problem. This makes meta-analysis and systematic review very difficult to interpret. There seems to be a reduction in the AMH level following surgery however there are studies that have found no significant reduction in AMH levels following surgery. Conclusion : Ovarian endometriomas are commonly seen in women with endometriosis. Laparoscopic surgery remains the treatment of choice, however new evidence suggests that such surgery negatively affects the ovarian reserve. Unfortunately there are serious flaws in surgical technique which can bias the results of these studies. We propose that using only experienced surgeons, performing the appropriate surgical technique, without using bipolar electrocoagulation, one can preserve AMH levels in women undergoing laparoscopic excision of ovarian endometriomas.
Source: Obstetrics and Gynaecology Forum 24, pp 27 –33 (2014)More Less
There is convincing evidence that many of common chronic diseases such as ischaemic heart disease (IHD), hypertension and diabetes mellitus have their origin, or at least part of it, during fetal development. The idea of the fetal origin of diseases, or the developmental origin of health and disease (DOHaD) as it is called today, originated in 1986 when Barker and Osmond, on division of the United Kingdom into different regions, observed a strong geographical relation between IHD mortality rates in 1968-78 and infant mortality in 1921-25. They further found that IHD strongly correlated with both neonatal and post neonatal mortality. As these neonatal conditions were associated with poor living circumstances, poor nutrition in early life was identified as a possible causing factor. In the follow-up of 5 654 men, born during 1911-1930, Barker et al. found that men with the lowest weights at birth and at one year had the highest death rates from IHD in later life, leading them to suggest that measures that promote healthy prenatal and postnatal growth may reduce deaths from IHD. In the follow up of 1 084 men, Law et al. found that the mean waist-to-hip ratio at 51 to 64 years was inversely related to birth weight. The same group studied 702 people born in Amsterdam during the famine of 1944-45 and found that prenatal exposure to poor nutrition, especially during late gestation, was linked to decreased glucose tolerance in adults.
Source: Obstetrics and Gynaecology Forum 24, pp 35 –40 (2014)More Less
Non-invasive prenatal testing (NIPT) refers to testing of cell-free fetal DNA in the maternal plasma, and is currently a rapidly evolving field. NIPT has recently become accepted as a screening test for certain aneuploidies, in particular Down syndrome (DS). NIPT testing is available in South Africa, although the genomic and bioinformatic processing of samples is performed elsewhere (most commonly the USA).
Several different approaches to NIPT testing are available, each with specific advantages and disadvantages. They all have a high sensitivity and specificity for detection of DS, but may be less accurate for other aneuploidies. Even for DS, NIPT is not a diagnostic test: some cases of DS will be missed, and positive results must be confirmed with an invasive test.
NIPT is indicated for screening for DS, especially in women at increased prior risk. Its role in testing for other aneuploidies, such as trisomy 13 or Turner syndrome, is less clear. NIPT is contraindicated where the fetus is at risk for a broader range of chromosome abnormalities - in this case invasive testing for karyotype should be offered.
The availability of NIPT is limited mainly by cost and the fact that it is not a medical aid benefit - it is currently for those who can afford to pay for it out of pocket.
In general an NIPT test can be performed from 10 weeks gestation, has a turn-around time of up to 2 weeks, and a failure rate of ~5%. Ideally, NIPT should be integrated into a broader Fetal Medicine service, and we present several options. NIPT should be offered in the context of genetic counselling. NIPT has potential value for O&G practices in more isolated geographical settings, but the practical and counselling pitfalls are significant.