L. Geerts - Academia.edu (original) (raw)

Papers by L. Geerts

Prenatal Diagnosis, 2001

Dimeric inhibin A was measured in maternal serum samples from 45 pregnancies affected by trisomy ... more Dimeric inhibin A was measured in maternal serum samples from 45 pregnancies affected by trisomy 21 and 493 samples from unaffected pregnancies at 10-14 weeks of gestation. Inhibin A levels in affected pregnancies were compared with levels of free b-hCG and PAPP-A in the same series. In the trisomy 21 group, the median multiple of the median (MoM) inhibin A was not significantly elevated (1.28 vs 1.00) with only 15.5% being above the 95th centile. In contrast, the median MoM free b-hCG was significantly increased (2.05 vs 1.00) with 36% above the 95th centile and PAPP-A was significantly reduced (0.49 vs 1.00) with 42% below the 5th centile. Inhibin A levels in the trisomy 21 group were significantly correlated with gestational age such that median levels rose from 1.04 at 11 weeks to 1.30 at 12 weeks and 1.67 at 13 weeks. These findings suggest that first trimester biochemical screening for trisomy 21, which is currently optimised using maternal serum free b-hCG and PAPP-A and fetal nuchal translucency, will not benefit from the inclusion of inhibin A.

The prevalence of monozygotic (MC) twins (twins developing from a single fertilised oocyte) is co... more The prevalence of monozygotic (MC) twins (twins developing from a single fertilised oocyte) is constant in different populations at around three per 1000 pregnancies.

Prenatal genetic screening is an integral part of general antenatal care and is regarded as stand... more Prenatal genetic screening is an integral part of general antenatal care and is regarded as standard of care for all pregnant women. All pregnant women < 20 weeks gestation should be offered some form of genetic screening and this should be discussed in an extensive pre-test counselling session. Late screening (after 20 weeks) may also be offered but will be limited by management options. Cell-free DNA testing has added another dimension to the landscape of prenatal screening but has to be appropriately used for the correct indication. Interpretation of risk for Down’s syndrome is a critical component of the screening process. A guideline would be to regard screening risks in absolute terms as there is no provision made to interpret risk in relative risk terms. An important safeguard to overcome the “relative risk” conundrum would be to inform all patients during pre-test counselling of an intermediate risk category generally between 1:300-1:1000 where cfDNA testing may be consid...

South African Medical Journal, 2013

Optimal management of pregnancy relies on accurate assessment of the gestational age (GA) of the ... more Optimal management of pregnancy relies on accurate assessment of the gestational age (GA) of the fetus; which can be determined by the history of the last menstrual period (LMP), clinical estimation of the 1st symphysis-to-fundal height measurement (FH) or ultrasonographic fetal biometry. However, many women fail to recall their LMP accurately. [1] Moreover, pregnancy duration and fertile period are highly variable, even for women with regular cycles. [1] FH suffers from poor reproducibility and high variability due to maternal and fetal factors; [2-4] its accuracy for dating has not been extensively studied [5-7] and requires FH dating charts (rather than growth charts). Ultrasonography (US) in the 1st, or early 2nd trimester, is highly reproducible [8] and widely used for dating, since early biological variability of fetal biometry is minimal. [9] In the past, certain LMP was used for dating as long as the GA was within 7, 10 or 14 days of the estimate of GA by US, [10] but now 1st, or 2nd trimester, US is increasingly recommended as the single dating method because of its smaller error rate. [1,11,12] The accuracy of dating GA by US in late pregnancy is less well studied, but may be clinically valuable. [13,14] The current policy in the Western Cape Province of South Africa (SA) provides for a routine US examination between 18-23 weeks of the clinically estimated GA for low-risk pregnancies since this reduces the number of presumptive post-and pre-term deliveries as well as the number of referrals to a higher level of care for suspected deviations in fetal growth. [15] The approximately 34% of women who typically present at >23 weeks [16] do not routinely receive US. Pregnancy dating is based on a pragmatic guideline incorporating information from the LMP, FH and early US (if available). [17] The accuracy of this guideline and the clinical value of late US-based GA dating have not been assessed. Our aim was to determine the accuracy of the different dating methods, and of their combinations, since they are currently widely used in SA. We performed a prospective study that compared the current US policy with a policy that included a routine booking scan. Objectives (i) Determine the accuracy of US in predicting the actual date of delivery (ADD), (ii) compare the incidence of GA-related outcomes and (iii) assess the influence of clinical variables on discrepancies between the dating methods. Methods The main study, described elsewhere, [16] was a prospective, interventional, before-and-after study in low-risk women (n=750 in each study arm) initiating antenatal care in 2 midwife-led clinics in the Metro East region, Cape Town, Western Cape. The study was approved by the Committee for Human Research, University of Stellenbosch (project no. N07/04/080) and a waiver of individual informed consent was granted. During the 1st period (October 2007-January 2008, comprising the control group), women received a routine US at 18-23 weeks GA, determined by clinical estimation based on a combination of the date of the LMP and FH. Additional scans were permitted, as per current policy, only for specified clinical indications. During the 2nd period, (February-April 2008, comprising the study group), a 'booking US scan' was obtained for all women within 7 days of their booking, regardless of GA. Singleton pregnancies continuing to >24 weeks were included if information was available for ≥1 dating method if ADD was known and ≥2 if ADD was not. We excluded pregnancies A comparison of pregnancy dating methods commonly used in South Africa: A prospective study

International Journal of Gynecology & Obstetrics, 2008

Objective: To establish a centile chart of cervical length between 18 and 32 weeks of gestation i... more Objective: To establish a centile chart of cervical length between 18 and 32 weeks of gestation in a low-risk population of women. Methods: A prospective longitudinal cohort study of women with a low risk, singleton pregnancy using public healthcare facilities in Cape Town, South Africa. Transvaginal measurement of cervical length was performed between 16 and 32 weeks of gestation and used to construct centile charts. The distribution of cervical length was determined for gestational ages and was used to establish estimates of longitudinal percentiles. Centile charts were constructed for nulliparous and multiparous women together and separately. Results: Centile estimation was based on data from 344 women. Percentiles showed progressive cervical shortening with increasing gestational age. Averaged over the entire follow-up period, mean cervical length was 1.5 mm shorter in nulliparous women compared with multiparous women (95% CI, 0.4-2.6). Conclusions: Establishment of longitudinal reference values of cervical length in a low-risk population will contribute toward a better understanding of cervical length in women at risk for preterm labor.

Journal of Affective Disorders, 2017

Background Women who have experienced childhood trauma may be at risk for postpartum depression, ... more Background Women who have experienced childhood trauma may be at risk for postpartum depression, increasing the likelihood of negative outcomes among their children. Predictive pathways from maternal childhood trauma to child outcomes, as mediated by postpartum depression, require investigation. Methods A longitudinal sample of South African women (N=150) was followed through pregnancy and postpartum. Measures included maternal trauma history reported during pregnancy; postpartum depression through six months; and maternal-infant bonding, infant development, and infant physical growth at one year. Structural equation models tested postpartum depression as a mediator between maternal experiences of childhood trauma and children's outcomes. A subset

South African Medical Journal, 2012

Ultrasound in Obstetrics and Gynecology, 2005

Ultrasound in Obstetrics & Gynecology, 2013

ABSTRACT Congenital rubella infection has been associated with a number of abnormalities includ... more ABSTRACT
Congenital rubella infection has been associated with a
number of abnormalities including cardiac, central nervous
system and placental complications. We present
a case with multiple fetal abnormalities detected on
prenatal ultrasound, and confirmed postnatally, that
included a single umbilical artery, severe tricuspid regurgitation,
micrognathia and agenesis of the inferior cerebellar
vermis. Postnatal echocardiography additionally
revealed unobstructed total anomalous pulmonary venous
drainage (TAPVD) into the coronary sinus. Placental
examination showed signs of placentitis, and polymerase
chain reaction on neonatal serum was positive
for rubella. Following a multidisciplinary team review,
it was decided to provide only supportive care, and
the infant died at 6 months of age owing to a respiratory
tract infection. To our knowledge, TAPVD and
agenesis of the inferior cerebellar vermis have not been
reported previously in association with congenital rubella
infection. This case illustrates how congenital infection
may present in atypical ways and stresses the importance
of considering congenital infection in the differential
diagnosis of fetal anomalies when multiple features are
present.

South African medical journal = Suid-Afrikaanse tydskrif vir geneeskunde, 1995

OBJECTIVE To determine the outcome of babies of mothers with severe rhesus (Rh) incompatibility t... more OBJECTIVE To determine the outcome of babies of mothers with severe rhesus (Rh) incompatibility treated by elective delivery when the amniotic optical density at 450 nm crossed Whitfield's action line (group 1), by plasmapheresis and immunotherapy (group 2) or by means of intra-uterine intravascular transfusions (group 3). STUDY DESIGN A retrospective study of 55 mothers and their 57 fetuses with severe Rh incompatibility at < 34 weeks' pregnancy duration. MAIN OUTCOME PARAMETERS Number of mothers in each treatment group, prevalence of intra-uterine death, hydrops, intra-uterine intravascular transfusions, cord haematocrit, cord bilirubin, number of liveborn babies, birth weight, neonatal death, hyaline membrane disease (HMD) and exchange transfusions. STUDY POPULATION AND SETTING All mothers and babies with severe Rh incompatibility (defined as an amniotic optical density of 450 nm in the upper and upper-mid zone on the Liley chart at < 34 weeks' pregnancy duratio...

O&G Forum, 2016

Counselling regarding congenital CMV infection is challenging as it may have a protracted clinica... more Counselling regarding congenital CMV infection is challenging as it may have a protracted clinical course from the time of suspected maternal infection until evidence of fetal damage. Gestational age at infection is the strongest predictor of adverse outcome but is often impossible to determine.Fetal infection, confirmed by amniotic fluid PCR, cannot be reliably diagnosed before 20 weeks gestation but this is usually not an issue outside of routine screening programmes. Although a positive PCR confirms fetal infection, it does not have prognostic value in the individual patient and it must be remembered that a negative PCR result is not fully reassuring as the sensitivity is not 100%. Fetal blood parameters, obtained by cordocentesis, are most useful for prognosticating in addition to ultrasound features, but manifestations of fetal damage (particularly central nervous system involvement) may only become apparent late in the third trimester. If imaging features of central nervous sy...

To determine the outcome of babies of mothers with severe rhesus (Rh) incompatibility treated by ... more To determine the outcome of babies of mothers with severe rhesus (Rh) incompatibility treated by elective delivery when the amniotic optical density at 450 nm crossed Whitfield's action line (group 1), by plasmapheresis and immunotherapy (group 2) or by means of intra-uterine intravascular transfusions (group 3). A retrospective study of 55 mothers and their 57 fetuses with severe Rh incompatibility at < 34 weeks' pregnancy duration. Number of mothers in each treatment group, prevalence of intra-uterine death, hydrops, intra-uterine intravascular transfusions, cord haematocrit, cord bilirubin, number of liveborn babies, birth weight, neonatal death, hyaline membrane disease (HMD) and exchange transfusions. All mothers and babies with severe Rh incompatibility (defined as an amniotic optical density of 450 nm in the upper and upper-mid zone on the Liley chart at < 34 weeks' pregnancy duration, previous fetal hydrops or Rh-related intra-uterine death (IUD), fetal hyd...

South African medical journal = Suid-Afrikaanse tydskrif vir geneeskunde, 1993

ABSTRACT

Journal of Pediatrics & Neonatal Care

Objective: To examine the effects of cigarette, marihuana and methamphetamine smoking and consump... more Objective: To examine the effects of cigarette, marihuana and methamphetamine smoking and consumption of alcohol during pregnancy on maternal serum alpha-fetoprotein (MSAFP) levels at 20-24 weeks. Study design: In the Safe Passage Study (SPS) more than 12,000 pregnant women were prospectively followed up during pregnancy and until the infant was one year old to examine the effects of exposure to alcohol during pregnancy on stillbirth and sudden infant death syndrome. The present study is a cross-sectional secondary analysis of MSAFP analyses done at 20-24 weeks gestation in 1,679 SPS participants, recruited at the Bishop

South African Journal of Obstetrics and Gynaecology, Apr 28, 2010

Ultrasound services in our rainbow nation-many shades of grey? EDITORIAL Like most things in Sout... more Ultrasound services in our rainbow nation-many shades of grey? EDITORIAL Like most things in South Africa, the fields of O&G ultrasound in general, and fetal medicine in particular, are characterised by a typical mix of First-and Third-World services. Although centres of excellence exist in both the private and public health care sectors, the main feature of O&G ultrasound in this country is a surprising inequity in access to high-quality services. This is unfortunately true for both the public and private sectors, albeit for different reasons.

Obstetrics and Gynaecology Forum, 2008

Human …, 2000

This extended series of 303 monochorionic twin pregnancies examined at 1014 weeks gestation expl... more This extended series of 303 monochorionic twin pregnancies examined at 1014 weeks gestation explores the possible association of increased fetal nuchal translucency thickness (NT) in the early prediction of severe twin-to-twin transfusion syndrome (TTS). Of 303 pregnancies, ...

South African Medical Journal

Neural tube defects (NTDs) include anencephaly, encephalocele and spina bifida (SB). Anencephaly ... more Neural tube defects (NTDs) include anencephaly, encephalocele and spina bifida (SB). Anencephaly is a lethal condition, whereas encephalocele and SB, which may cause long-term disability, are a considerable burden to families and the healthcare system, [1,2] and are relatively common birth defects. In South Africa (SA), studies give estimated population prevalence rates of 0.99-3.8 per 1 000 live-born infants. [3-6] Folic acid supplementation in the peri-conceptional period [7] or fortification of staple foods [8] has been shown to reduce the prevalence of NTDs. In SA, the introduction of folic acid fortification of maize and wheat products in 2003 was associated with a 31% reduction in NTD prevalence at sentinel sites, from 1.41 to 0.98/1 000 births. [9] Another preventive option is prenatal diagnosis by ultrasound, with the choice of termination of pregnancy (TOP), which has become increasingly available in parts of SA. Despite these changes, there are minimal data on NTD prevalence after 2003. Effective surveillance of NTDs and other birth defects is important for various reasons, e.g. to establish burden of disease, monitor trends in birth prevalence, assess impact of preventive measures and detect outbreaks. The last role is highlighted by the recent link between maternal Zika virus infection and microcephaly in offspring, [10] and the possible link between maternal use of the antiretroviral drug dolutegravir and NTDs. [11] The National Department of Health (NDoH) has a populationbased birth defect surveillance system, which appears to be ineffective. [12] Hospital-based surveillance is an easier alternative, but less optimal because of lack of a defined denominator. It therefore works best where it captures most of the population of interest in a geographical region. [13] We anticipated this to be largely true in Western Cape Province, SA, for NTDs, or at least for SB, given that both prenatal diagnosis and paediatric management are centralised at tertiary hospitals with defined catchment areas. Furthermore, most NTDs are readily visible at birth. We therefore aimed to assess the detection of NTDs at a tertiary hospital using a range of prenatal, perinatal and postnatal data sources, and to estimate the impact of prenatal diagnosis and birth prevalence for the referral area. Methods The study was conducted at Tygerberg Academic Hospital (TAH), a tertiary public hospital in the Western Cape. It is a referral centre for This open-access article is distributed under Creative Commons licence CC-BY-NC 4.0.