498 Letters February 1997 Am j Obstet Gynecol

Table L Reversal of adaptation: Review of l i terature

Birth Fetal weight

Author, year Gestation death (gin)

Marl and Wasserstrum, 27 wk 5 days 1 day 430 1991

Chandran et aI., 1991 24 wk 0 days 12 hr 400 Huang et al., 1993 25 wk 0 days 7 days 390 Rizzo et al., 1994 29 wk 5 days 6 hr 540 Chirit et al., 1995 28 wk 3 days 1 day 760 Rowlands and Vyas, 25 wk I days 2 days 410

1995 Rowlands and Vyas, 28 wk 2 days 2 days 475

1995 Sepulveda et al., 1996 29 wk 0 days 7 days 460

cerebral artery was d o c u m e n t e d after loss of the brain- sparing effect and before in t rauter ine death. Jakobovits suggests that this abnormal Doppler f inding could be the result of increased intracranial pressure by external or internal factors. In our case care was taken to avoid external pressure to the fetal head by the transducer, and there was no evidence of intracranial hemor rhage nor hydrocephaly at pos tmor tem examinat ion. There fo re we believe that this pat tern truly represents one of the latest events sur rounding the general ized vascular collapse preced ing fetal death.

We agree with Jakobovits that reversal of cerebral redistr ibution is not always associated with i m m i n e n t fetal death. As our case demonstrates, the fetus can survive in u tero even 1 week after losing the brain- sparing effect. However, the currently available informa- tion confirms the original s ta tement of Mari and Wass- erstrum, 1 that expedi te delivery would be necessary to avoid intrauter ine death. Indeed, a review of the litera- ture shows that fetal death almost always occurs within the following 48 hours (Table I). The quest ion whether detect ion of reversal of adaptat ion in a severely growth- restricted fetus provides a window in which exped ien t delivery can allow survival of a neurological ly intact individual remains unanswered. Evidence f rom fetal b lood sampling indicates that these fetuses are severely hypoxemic with possible super imposed cerebral edema. 2 Reverse end-diastolic flow in the middle cerebral artery should be taken in context of poor umbil ical flow, ol igohydramnios, and severe in t rautrauter ine growth re- striction; when they all occur together the out look is grim.

Waldo Sepulveda, MD

Fetal Medicine Center, Clinica Las Condes, Casilla 268, Santiago 34, Chile

Michael J. Peek, PhD

Department of Obstetrics and Gynaecology, Canberra Clinical School, Canberra Hospital, P.O. Box 11, Woden, Australian Capital Territory 2606, Australia

REFERENCES 1. Mari G, Wasserstrum N. Flow velocity waveforms of the fetal

circulation preceding fetal death in a case of lupus anticoag- ulant. Am J Obstet Gynecol 1991;164:776-8.

2. Vyas S, Nicolaides KH, Bower S, Campbell S. Middle cerebral artery flow velocity waveforms in fetal hypoxaemia. Br J Obstet Gynaecol 1990;97:79%803.

A complete list of references is available from the authors on request.

6/8/79163

Data on episiotomy rates need analysis by parity

To the Editors: We read with interest the paper on episiotomy by Lede et al. (Lede RL, Belizan JM, Carroli G. Is rout ine use of episiotomy justified? Am J Obstet Gynecol 1996;174:1399-402) and we agree that ne i ther high rates of episiotomy nor rout ine episiotomy can be justif ied in the face of the available studies. It is now widely accepted that the inc idence of per ineal t rauma is an impor tan t index of care and this informat ion is therefore, inc luded in our annual clinical report .

Table I. Episiotomy data analyzed by parity

NuUiparous Multigravid women women Total

First-degree tear 282 (12.4%) 1102 (27.2%) 1384 (21.5%) Second-degree 250 (10.3%) 360 (8.9%) 610 (9.5%) Third-degree, muscle 23 (1%) 10 (0.2%) 33 (0.4%) Third-degree, anal 11 (0.5%) 3 (0.1%) 14 (0.2%)

m u c o s a

Episiotomy 1031 (42.9%) 425 (10.4%) 1457 (22.6%)

O u r audit , 1 however , h ighl ights the impor t ance of analyzing such informat ion by parity (Table I) and we believe that such analysis is an essential e l emen t of any study investigating episiotomy rates and in audit feed- back to individual practi t ioners where the aim is to reduce episiotomy rates. Our overall episiotomy rate remains low at 22.6% with a third-degree tear rate of 0.6%. Our results show that third-degree tears are more likely to occur in nul l iparous women; the incidence has r ema ined low in spite of our low episiotomy rate. We propose that any analysis examining the impact of lower episiotomy rates on the incidence of third-degree tears must correct for parity.

Richard Greene, MD, Franfois Gardeil, MD, and Michael J. Turner, MD

Coombe Women's Hospital, Academic Center, Dublin 8, Ireland

REFERENCE 1. Coombe Women's Hospital annual clinical report 1994.

Dublin: Coombe Women's Hospital, 1994.

6/8/79165

Reply

To the Editors: We are pleased with the comments of Greene et al. about our clinical opin ion article.

It is impor tan t to poin t out that in the hospital of these authors an overall inc idence of episiotomy of 22.6% with