Matthew Jolly

Risk factors for macrosomia and its clinical consequences: a study of 350,311 pregnancies.

OBJECTIVES To identify demographic risk factors for either birthweight >4kg or over the 90th centile and to quantify the obstetric risks. STUDY DESIGN Data from 350,311 completed singleton pregnancies in the North West Thames Region between 1988 and 1997 were analysed using logistic regression. Predisposing factors and pregnancy outcome were compared by birthweight 2.5-4kg (n=259,902) and >4kg (n=36,462) and 10th-90th centile (n=279,780) and >90th centile (n=34,937). RESULTS Macrosomia defined as birthweight >90th centile was more likely in women whose BMI >30 (kg/m(2)) (odds ratio (OR) 2.08; confidence intervals (CI) 1.99, 2.17), parity >4 (OR 2.20; CI 2.02, 2.40), age >40 (OR 1.22; CI 1.11, 1.35) and in women with pre-existing diabetes (OR 6.97; CI 5.36, 8.16) or who developed gestational diabetes (OR 2.77; CI 2.51, 3.07). Macrosomia defined by birthweight >4kg was better than birthweight >90th centile at predicting morbidity and was associated with a prolonged first and second stage of labour (OR 1.57; CI 1.51, 1.63) and (OR 2.03; CI 1.88, 2.19), respectively, an increased risk of instrumental vaginal delivery (OR 1.76; CI 1.68, 1.85), third degree perineal trauma (OR 2.73; CI 2.30, 3.23), emergency caesarean section (OR 1.84; CI 1.75, 1.93), postpartum haemorrhage (OR 2.01; CI 1.93, 2.10), Apgar score <4 (OR 1.35; CI 1.03, 1.76), and admission to the special care baby unit (OR 1.51; CI 21.38, 1.68). CONCLUSION Macrosomia is more common in mothers who are obese, older or diabetic and is associated with significant obstetric morbidity.

Is maternal underweight really a risk factor for adverse pregnancy outcome? A population-based study in London

Objective To determine the maternal and fetal risk of adverse outcome during pregnancy in relation to low maternal body mass index in an unselected population.

Validation of the Quintero staging system for twin-twin transfusion syndrome

OBJECTIVE To validate an established staging system for twin‐twin transfusion syndrome. METHODS Prospective observational study in a tertiary referral fetal medicine center of 52 consecutive cases of twin‐twin transfusion syndrome. Each pregnancy was assessed longitudinally for a variety of prognostic factors including fetal biometry, amniotic fluid volume, arterial and venous Doppler sonogram abnormalities, and the presence of hydrops. Data were used to determine stage at diagnosis and first treatment, and worst stage throughout pregnancy. Perinatal outcome was assessed by stage. Management comprised serial amnioreduction, septostomy, selective reduction, or delivery, alone or in combination. RESULTS Median gestation at presentation and first treatment were both 21 weeks (range 14–34 and 15–34), and at delivery it was 29 weeks (range 16–40). Sixty‐three percent of pregnancies (33 of 52) were at least stage III at presentation. Forty‐five percent of pregnancies (22 of 49) progressed to a more advanced stage. Overall survival was 47% (47 of 100), with no difference between donor and recipient fetuses (40% [20 of 50] versus 54% [27 of 50] [χ2 P < .5]). Survival rates were 58% (15 of 26), 60% (six of ten), 42% (20 of 48), 43% (six of 14), and 0% (none of two) for stages I–V, respectively, with no significant influence of stage at presentation on survival. Survival was poorer where stage increased, versus decreased (27% [12 of 44] versus 94% [17 of 18] χ2 P < .001). Kaplan‐Meier survival curves indicated that staging at presentation identified pregnancies at greater risk of earlier rather than later gestational perinatal loss. CONCLUSION The Quintero staging system did not distinguish good from bad outcome at presentation, and thus should be used with caution in guiding initial management of twin‐twin transfusion syndrome. However, prognosis was influenced by a change in stage, and pregnancies progressing to higher stage disease were at increased risk of earlier perinatal loss. Staging may thus be more useful in monitoring disease progression.

Interstitial laser: a new surgical technique for twin reversed arterial perfusion sequence in early pregnancy

Current treatments for twin reversed arterial perfusion sequence are associated with significant morbidity and most are not feasible in early gestation. We report the use of an interstitial laser in two pregnancies complicated by this sequence at 14 and 15 weeks, respectively. A 600μm laser fibre was introduced via a 17 gauge needle into the abdomen of the perfused twin close to the vitelline artery and umbilical vein, which were occluded by neodymium:yttrium aluminium garnet (Nd:YAG) laser. Both pregnancies continued uneventfully and each resulted in the birth of a healthy baby at term.

Test Amnioinfusion to Determine Suitability for Serial Therapeutic Amnioinfusion in Midtrimester Premature Rupture of Membranes

Objective: To evaluate whether a test amnioinfusion procedure is useful in selecting cases of midtrimester preterm premature rupture of membranes (PPROM) which may benefit from serial amnioinfusions if the initial fluid is retained. Study Design: The Centre for Fetal Care database between 1992 and 2000 was reviewed for women with PPROM <26 weeks who had undergone amnioinfusion. Amniotic fluid index (AFI) was assessed before and after a test amnioinfusion procedure. Those who retained fluid ≧48 h underwent serial AFI assessment with a view to serial amnioinfusion when oligohydramnios recurred. Results: Eighty-five amnioinfusion procedures were performed in 60 women with oligohydramnios. Nineteen of these women presented with confirmed PPROM at a median gestation of 19 (range 15–22) weeks and severe olighohydramnios (median AFI 1, range 0–3 cm), in whom 20 test amnioinfusions were carried out. Two amnioinfusions were abandoned during the procedure because of fetal bradycardia and both mothers opted for termination of pregnancy. Only 4 women retained fluid during the test amnioinfusion, 1 of whom miscarried at 19 weeks before serial amnioinfusion could be started. The remaining 3 underwent a median of 4 (range 1–6) serial amnioinfusion procedures; none had evidence of pulmonary hypoplasia. Thirteen (68%) leaked fluid within 48 h; within this group there was 1 subsequent miscarriage and 9 pregnancy terminations. The remaining 3 pregnancies resulted in livebirths 2 of which had pulmonary hypoplasia with 1 early neonatal death. Overall survival was poor (4/19), largely attributed to the high incidence of terminations in the presence of persistent severe oligohydramnios. In continuing pregnancies reaching viability survival was 67% (4 of 6). Conclusion: Three quarters of women with mid-trimester PPROM lose fluid at test amnioinfusion and therefore would not be suitable candidates for serial amnioinfusion. However, if infused fluid is retained, this allows subsequent serial amnioinfusion and prolongation of pregnancy in about 75%, with an attendant decrease in the risk of pulmonary hypoplasia. However, even successful serial amnioinfusion remains associated with procedure-related complications (i.e. chorioamnionitis, placental abruption) which themselves may predispose to preterm delivery.

X-linked inheritance of Dandy-Walker variant.

We report a family in which two sisters had three male fetuses with isolated Dandy-Walker variant (DWV) diagnosed on antenatal ultrasound. DWV is one part of a spectrum of abnormalities related to Dandy-Walker malformation (DWM) which commonly occur in association with other anomalies with or without chromosome abnormalities. The majority of cases are sporadic but rare reports of recurrence in siblings exist. This is the second report suggesting that isolated DWM/DWV can be inherited as an X-linked recessive trait.

Niobium η-cyclopentadienyl compounds with imido and amido ligands derived from tert-butylamine

The niobium η-cyclopentadienyl compounds with imido and amido ligands [Nb(η-C5H5)(NtBu)(NHtBu)Cl] 1,* [Nb(η-C5H5)(NtBu)(NHtBu)nBu] 2, [Nb(η-C5H5)(NtBu)(NHtBu)2] 3, [Nb(η-C5H5)(NtBu)(NHtBu)Me] 4, [Nb(η-C5H5)(η1-C5H5)(NtBu)(NHtBu)] 5, [Nb{(η-C5H4)CMe2(η1-C5H4)}(NtBu)(NHtBu)] 6, [Nb(η-C5H5){N(C6H3iPr2-2,6)}(NHtBu)Cl] 7,* [Nb(η-C5H5){N(C6H3iPr2-2,6)}(NHtBu)Me] 8, [Nb(η-C5H5)(NtBu)(NEt2)Cl] 9 and [Nb(η-C5H5)(NtBu)(NHtBu)(NEt2)] 10 have been prepared (* indicates the crystal structure has been determined). A correlation between the chemical shift of the NH proton and the value of Δδ measured between the α and β carbons of the tert-butyl groups of the amido ligands is discussed in relation to the degree of electron donation from the amido ligand to the niobium centre.

Pairwise ligand exchange reactions in tetrahedral and pseudo-tetrahedral transition metal complexes

Ligand exchange reactions between various transition-metal complexes of the form [Mo(Q)2X2], [M(Q)CpX2] and [Mo(Q)2CpX], where Q and X are di-anionic and mono-anionic ligands, respectively, and M is Nb or Ta, have been studied. The formal electron count at the metal, and also the steric and electronic properties of the supporting ligands, are found to influence exchange rates, while ligand steric and electronic properties affect equilibrium constants.

The role of Brønsted acid catalysis in inter-metal ligand exchange reactions

A Bronsted acid is shown to catalyse the inter-metal exchange of mono-anionic (alkoxide and amide) and dianionic (imido) ligands in four-coordinate molybdenum complexes of the type Mo(NR)2(X)2 (R = alkyl, aryl; X = alkoxide, amide).

Imido ligand reactivity in four-co-ordinate bis(imido) complexes of molybdenum(VI)

The four-co-ordinate complexes Mo(NR)2(OBut)2(R = But or 2,6-Pri2C6H3) undergo imido ligand exchange reactions with benzaldehyde, amines and dioxygen; the reaction of Mo(NR)2(OBut)2(R = 2,6-Pri2C6H3) with phenyl isocyanate, however, leads to the formation of a bis(metallacycle) complex.